| Age | Commit message (Collapse) | Author | Files | Lines |
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Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
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A use-after-free was detected in snd_card_do_free() when a sound card
managed by devres is unbound while a user-space application still holds an
open file descriptor.
For managed cards, the memory is allocated using devres_alloc(), and its
release function is set to __snd_card_release(), which calls
snd_card_free(). When the device is unbound, the unbind thread calls
snd_card_free(), which drops a reference to the card's device. If the user
thread still has an open file descriptor, the reference count does not
reach zero, and the unbind thread blocks on wait_for_completion(&released).
When the user thread closes the file descriptor, it drops the final
reference, invoking the device release callback release_card_device(),
which calls snd_card_do_free(). snd_card_do_free() performs cleanup and
calls complete(card->release_completion). This wakes up the unbind thread,
which returns from snd_card_free() and __snd_card_release(). The devres
core then immediately frees the memory block containing the snd_card
structure.
Meanwhile, the user thread continues execution in snd_card_do_free() and
evaluates `if (!card->managed)`. It reads the `managed` boolean from the
snd_card structure that was just freed by the unbind thread, triggering a
KASAN use-after-free.
Fix this by caching the value of card->managed in a local variable before
calling complete(). This ensures that the card pointer is not dereferenced
after the unbind thread has been woken up and potentially freed the card.
BUG: KASAN: use-after-free in snd_card_do_free sound/core/init.c:604
[inline]
BUG: KASAN: use-after-free in release_card_device+0x1ab/0x1b0
sound/core/init.c:153
Read of size 1 at addr ffff8881912ec909 by task syz-executor130/5857
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
snd_card_do_free sound/core/init.c:604 [inline]
release_card_device+0x1ab/0x1b0 sound/core/init.c:153
device_release+0xc4/0x1f0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x222/0x550 lib/kobject.c:737
snd_card_file_remove+0x331/0x390 sound/core/init.c:1125
snd_pcm_release+0x12c/0x160 sound/core/pcm_native.c:2986
__fput+0x418/0xa50 fs/file_table.c:512
fput_close_sync+0x11f/0x240 fs/file_table.c:617
__do_sys_close fs/open.c:1511 [inline]
__se_sys_close fs/open.c:1496 [inline]
__x64_sys_close+0x7e/0x110 fs/open.c:1496
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Fixes: e8ad415b7a55 ("ALSA: core: Add managed card creation")
Assisted-by: Gemini:gemini-3.6-flash Gemini:gemini-3.1-pro-preview syzbot
Reported-by: syzbot+7061d72c26b7daebe2b4@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7061d72c26b7daebe2b4
Link: https://syzkaller.appspot.com/ai_job?id=24752a23-f0b6-49c1-bf20-4fa89c2e7eb2
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Link: https://patch.msgid.link/02042186-27b7-42a9-b64e-f93ce8fbe05a@mail.kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_midi_input_event() must not be running while a rawmidi substream is
closing, since this can lead to the trigger state becoming out-of-step
through this sequence in snd_rawmidi_input_trigger():
snd_rawmidi_input_trigger(up=0)
snd_midi_input_event()
-> snd_rawmidi_kernel_read()
-> snd_rawmidi_input_trigger(up=1)
-> cancel_work_sync()
which ends with the underlying device being active unexpectedly.
When this is called from close_substream(), further input can re-trigger
the input event leaving it running after rawmidi_release_priv() has set
rfile->rmidi to NULL which leads to:
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b0
Call trace:
snd_midi_input_event+0x3c/0x134 [snd_seq_midi] (P)
snd_rawmidi_input_event_work+0x1c/0x2c
process_one_work+0x150/0x3a4
worker_thread+0x190/0x318
Apply a similar approach to commit ef7607ab1c8ad ("ALSA: seq: midi:
Serialize output teardown with event_input") which fixed the same issue
in the output direction, but updated to use RCU following Takashi Iwai's
proposed follow-on patch [1].
With this change in place, midisynth_unsubscribe() clears the input file
so snd_midi_input_event() will not re-trigger the stream and will be
quiesced by the cancel_work_sync() in snd_rawmidi_input_trigger().
[1] https://lore.kernel.org/linux-sound/20260813144224.753399-1-tiwai@suse.de/
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Link: https://patch.msgid.link/20260813150810.795393-1-jkeeping@inmusicbrands.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The recent fix for serializing the output teardown introduced a
spinlock invocation at every MIDI output event via event_process_midi.
Since this is a hot path, let's do performance optimization with RCU.
The new output_substream __rcu pointer is published via
rcu_assign_pointer() in midisynth_use() after output_rfile is set, and
cleared in midisynth_unuse() before the resource teardown.
event_process_midi() reads it under rcu_read_lock() and bumps
output_use_lock inside that section, which is necessary to close the
window between the pointer dereference and the refcount increment.
midisynth_unuse() calls synchronize_rcu() before snd_use_lock_sync():
this guarantees that any reader who obtained a non-NULL pointer has
already called atomic_inc (output_use_lock), so the subsequent
snd_use_lock_sync() sees the correct in-flight count.
Fixes: ef7607ab1c8a ("ALSA: seq: midi: Serialize output teardown with event_input")
Link: https://patch.msgid.link/20260813144224.753399-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Now that the bitwise parameter definitions are gone for PCM
parameters, we don't have to cast with ugly __force prefix.
Simply drop those superfluous casts
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260812060557.80445-7-tiwai@suse.de
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Now that the bitwise parameter definitions are gone for PCM
parameters, we don't have to cast with ugly __force prefix.
Simply drop those superfluous casts.
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260812060557.80445-6-tiwai@suse.de
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Now that the bitwise parameter definitions are gone for control
parameters, we don't have to cast with ugly __force prefix.
Simply drop those superfluous casts.
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260812060557.80445-5-tiwai@suse.de
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Now that the bitwise parameter definitions are gone for PCM
parameters, we don't have to cast with ugly __force prefix.
Simply drop those superfluous casts.
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260812060557.80445-3-tiwai@suse.de
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The struct describes a bounce payload of an error code followed by the
original event and its external data. No kernel has ever sent that.
Before commit efc86691e4d8 ("ALSA: seq: Fix kernel heap address leak in
bounce_error_event()") the kernel emitted no SNDRV_SEQ_EVENT_BOUNCE at
all, and since then it sends the event record alone.
Nothing has ever read it either. Its only accessor,
snd_seq_event_bounce_ext_data(), has had no caller for the whole git
history, and it did not even compile until commit c7e0b5bf9fff ("[ALSA]
Remove xxx_t typedefs: Sequencer") incidentally repaired the type name
it referred to, three years after the git import. Drop the accessor
along with the struct.
This removes a definition from a UAPI header. Since no kernel ever
produced the layout, nothing can have parsed it, but a program that
merely names the type will need to stop.
Suggested-by: Takashi Iwai <tiwai@suse.de>
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
Link: https://patch.msgid.link/20260812141506.4016387-1-sammiee5311@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The bounce_error_event() embeds the failed event in the bounce payload
by pointing data.ext.ptr at it. When that event is a queued
variable-length event, its own data.ext.ptr holds the address of its
first extension cell, put there by snd_seq_event_dup(). The payload
goes out verbatim through snd_seq_expand_var_event(), so the address
reaches userspace.
That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear
variable event pointer on read") removed from the event header. The
read path still clears it there, just above the call that expands the
payload.
Embed a sanitised copy instead, treated exactly as snd_seq_read()
treats the header. A stack copy is enough because delivery is
synchronous and snd_seq_event_dup() copies before returning.
An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE,
queueing a variable-length event to a port that does not exist and
reading the bounce back. Eight bytes on 64-bit, from its own pool.
Fixes: efc86691e4d8 ("ALSA: seq: Fix kernel heap address leak in bounce_error_event()")
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
Link: https://patch.msgid.link/20260811131835.3837024-1-sammiee5311@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The UMP sequencer client protects its output rawmidi file (out_rfile)
with an rwlock (output_lock). seq_ump_process_event(), the port's
event_input callback, reads out_rfile.output under read_lock on every
delivered UMP event, while the open/close paths (serialized by
ump->open_mutex) publish and clear out_rfile under write_lock.
Output is opened/closed only on the subscribe/use lifecycle while
delivery happens per event, so this is another read-mostly hot path.
Convert it to RCU and drop the rwlock. out_rfile is an embedded struct
rather than a pointer, so instead of restructuring it, add an
RCU-protected shadow of the substream (out_substream) for the reader;
out_rfile itself becomes writer-only state accessed solely under
open_mutex. The reader now runs lock-free under rcu_read_lock() via
rcu_dereference(), and open publishes the substream with
rcu_assign_pointer().
On close the substream is cleared with rcu_assign_pointer(NULL) and the
rawmidi is released only after synchronize_rcu(), so no reader in the
delivery path can still be writing to the substream when
snd_rawmidi_kernel_release() runs.
Dropping write_lock_irqsave() from the writers is safe: they run in
process context under open_mutex, and the sole atomic reader now uses
RCU, which is IRQ-safe.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260810133711.42483-6-tiwai@suse.de
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Each virmidi device keeps a list of its opened input files (filelist)
protected by both an rwlock (filelist_lock) and a rw_semaphore
(filelist_sem). snd_virmidi_dev_receive_event() walks the list on the
sequencer event input path -- read_lock() when the event is delivered in
atomic context, down_read() otherwise -- decoding each incoming event
into the file's rawmidi buffer. The writers (input open/close) take both
locks to add/remove entries.
This is another typical dual-lock read-mostly pattern as the port
subscriber list: files are opened/closed rarely while the receive
callback runs per event. Let's convert the traversal to RCU and drop
the rwlock; the existing filelist_sem keeps serializing the writers.
The atomic input path now runs lock-free under rcu_read_lock(), and
both readers share a single list_for_each_entry_rcu() (valid under the
rwsem via lockdep_is_held()). The writers switch to
list_add_tail_rcu() / list_del_rcu().
snd_virmidi_input_close() freed the entry (parser and struct)
immediately after list_del. A concurrent lockless reader in the atomic
path may still be dereferencing it, so the close path now waits for an
RCU grace period after list_del_rcu() before freeing; synchronize_rcu()
is used rather than kfree_rcu() because the parser must also be released
after the grace period, not just the struct. Non-atomic readers are
already excluded by the down_write, so only the atomic RCU readers need
the grace period.
Dropping write_lock_irq() from the writers is safe: no writer runs in
atomic/IRQ context, and the sole atomic reader now uses RCU, which is
IRQ-safe.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260810133711.42483-5-tiwai@suse.de
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The sequencer keeps a global table of clients (clienttab[]) indexed by
client id, protected by the global clients_lock spinlock. The lookup
snd_seq_client_use_ptr() reads a slot and takes a use_lock reference on
the client, and this runs on the event delivery hot path: every
dispatched event resolves its destination (and often source) client
through it. The spinlock's only job on the read side is to make the
"pointer is non-NULL" test and the reference increment indivisible with
respect to the writer that nulls the slot and then drains the refcount.
Clients come and go rarely but delivery happens constantly, so this is
yet another read-mostly case as the port and subscriber lists.
Convert the table to RCU: the read side now runs lock-free under
rcu_read_lock() and takes the use_lock reference via
rcu_dereference(), removing contention on the single global spinlock
from the delivery path. The writers keep clients_lock (still needed
to serialize slot allocation) and publish / unpublish via
rcu_assign_pointer(); creation and destruction remain serialized at a
higher level by register_mutex.
As with the ports, the client is not freed via kfree_rcu(): its lifetime
is governed by the use_lock refcount drained in seq_free_client1().
list_del under the old spinlock excluded a concurrent lookup from taking
a new reference once the slot was nulled; rcu_assign_pointer(NULL) offers
no such exclusion, so a reader still holding the old pointer can grab a
reference after the unpublish. seq_free_client1() therefore calls
synchronize_rcu() after nulling the slot and before snd_use_lock_sync():
once the grace period elapses no new reference can appear, and the
existing drain then frees the client safely.
clienttablock[] keeps its slot-reservation role (create/free are
serialized by register_mutex); its read on the lookup path only gates
module autoload, so a lockless read is harmless. Dropping the spinlock
from the read path is safe: clients_lock is now taken only by the
process-context writers, and the sole atomic reader uses RCU, which is
IRQ-safe.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260810133711.42483-4-tiwai@suse.de
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Each sequencer client keeps a list of its ports (ports_list_head)
protected by both an rwlock (ports_lock) and a mutex (ports_mutex).
The rwlock is taken read-side on the event delivery hot path:
snd_seq_port_use_ptr() walks the list to resolve a port on every
dispatched event, while the mutex serializes port creation/deletion.
Ports change rarely but delivery happens constantly, so this is the
another read-mostly case as the port subscriber list. Convert the
port list traversal to RCU and drop the rwlock entirely; the existing
ports_mutex keeps serializing the writers. The atomic delivery path
(snd_seq_port_use_ptr(), snd_seq_port_query_nearest()) now runs
lock-free under rcu_read_lock() instead of contending on the shared
rwlock.
The writers switch to list_add_tail_rcu()/list_del_rcu().
snd_seq_insert_port() now stores the port number and name before
publishing the node so RCU readers only ever observe a fully
initialized port. One drawback is that snd_seq_delete_all_ports()
drops the O(1) splice trick and unlinks each port individually,
though: the splice repointed the last port's ->next away from the list
head, which would send a concurrent lockless reader off the end of the
list.
Unlike the subscriber objects, ports are not freed via kfree_rcu():
port_delete() must drain outstanding use_lock references (and run
private_free()) synchronously. The rwlock previously guaranteed that
no reader could take a new use_lock reference once the port was
unlinked -- list_del under write_lock excluded snd_use_lock_use()
under read_lock. list_del_rcu() offers no such exclusion, so a reader
still traversing the list can grab a reference after the unlink.
port_delete() therefore calls synchronize_rcu() after the port has
been unlinked and before snd_use_lock_sync(): once the grace period
elapses no new reference can appear, and the existing drain then frees
the port safely.
Dropping write_lock_irq() from the writers is safe: no writer runs in
atomic/IRQ context, and the sole atomic reader now uses RCU, which is
IRQ-safe.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260810133711.42483-3-tiwai@suse.de
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Each sequencer port keeps two subscriber groups (c_src and c_dest),
each protected by both an rwlock (list_lock) and a rw_semaphore
(list_mutex). The rwlock is taken read-side in the event delivery hot
path (__deliver_to_subscribers()) for delivering every event to
subscribers, while the mutex serializes subscribe/unsubscribe and
covers the sleepable delivery and query walks.
Subscriptions change rarely but delivery happens constantly, so this is
a textbook read-mostly case. Convert the subscriber list traversal to
RCU and drop the rwlock entirely while keeping the existing list_mutex
for serializing the writers. The atomic delivery path now runs
lock-free under rcu_read_lock() instead of contending on the shared
rwlock.
Along with the conversion to RCU, the subscriber lists are switched
from list_head to hlist so that removal can use hlist_del_init_rcu():
it keeps the ->next pointer intact for concurrent readers while
clearing ->pprev, which lets the double-deletion guard (added in
commit 13d5e5d4725c) keep detecting an already-removed entry via
hlist_unhashed().
Dropping write_lock_irq() from the writers is safe: no writer runs in
atomic/IRQ context, and the sole atomic reader now uses RCU, which is
IRQ-safe. Port lifetime handling (use_lock/closing drain in
port_delete()) is orthogonal and unchanged.
Note that the conversion to RCU has another merit: it automatically
"fixes" the (rather false) lockdep warnings for the doubly read-locks
of the same subscriber list, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260810133711.42483-2-tiwai@suse.de
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The cvt_legacy_sysex_to_ump() initialises only the first word of the
output packet and ORs the data bytes into it. The second word is left
alone, and the conversion context is kept across calls, so it still
carries the previous packet's bytes. Those stale bits corrupt the new
data. Any SysEx longer than six data bytes is affected.
A SysEx with the twelve data bytes 01..0c comes out as:
30160102 03040506
30260708 0b0e0f0e
The second packet declares six data bytes and four of them are wrong,
inside the declared length.
The sibling cvt_legacy_cmd_to_ump() already clears the second word. Do
the same here.
Fixes: 0b5288f5fe63 ("ALSA: ump: Add legacy raw MIDI support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
Link: https://patch.msgid.link/20260808014554.3550153-1-sammiee5311@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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There's a large number of vm_get_page_prot(vma->vm_flags) invocations.
Make life easier by introducing vma_get_page_prot() parameterised by the
VMA.
This also makes converting vm_get_page_prot() to vma_flags_t easier.
Also update the userland VMA tests to reflect the change.
No functional change intended.
Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-8-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Jani Nikula <jani.nikula@intel.com> # for i915
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> [DRM]
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When opening a legacy rawmidi device for a UMP, it may re-open an
existing rawmidi device for appending to a substream, leading to a
lockdep warning due to rmidi->open_mutex taken twice -- but the
rawmidi devices are completely individual, hence it's a
false-positive.
For avoiding the warning, modify the helper to open a rawmidi instance
with a proper locking subclass from the UMP legacy open.
Unfortunately, there is no good way to achieve it with guard(), so
reverted to the manual mutex calls again.
Reported-by: syzbot+d10d58fc99caa0489796@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/6a6a9634.57649fcc.360844.000b.GAE@google.com
Link: https://patch.msgid.link/20260806101352.1291581-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The fixed-size components field in SNDRV_CTL_IOCTL_CARD_INFO can be too
small on systems with many audio devices.
Keep the existing struct snd_ctl_card_info ABI intact and add a new
ioctl SNDRV_CTL_IOCTL_CARD_BYTES that carries a variable-length payload
selected by a type discriminator. The first defined type
SND_CTL_CARD_BTYPE_COMPONENTS returns the full components string. The
ioctl is designed to be reused for other variable-length card payloads
in the future.
The user-space caller may set data_allocated == 0 (or data == NULL) to
query the required length; otherwise the kernel copies the payload into
the user buffer and writes back the actual length in data_len.
When the legacy components field in struct snd_ctl_card_info is
truncated, '>' is written just before the NUL terminator to signal to
user-space that the full string is available via the new ioctl.
card->components is now dynamically allocated and grown in 32 byte
increments via krealloc(), capped at 512 bytes.
Link: https://github.com/alsa-project/alsa-lib/pull/494
Suggested-by: Jaroslav Kysela <perex@perex.cz>
Suggested-by: Takashi Iwai <tiwai@suse.com>
Signed-off-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260720103505.1860399-2-mstrozek@opensource.cirrus.com
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Clean up trailing whitespace in preparation for the card components
changes.
Signed-off-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260720103505.1860399-1-mstrozek@opensource.cirrus.com
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Pull 7.2 devel branch for applying further patches cleanly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_pcm_drain() on a linked stream parks an on-stack wait entry on the
drained peer's runtime->sleep, and after schedule_timeout() removes it
only if that peer is still found in the caller's group. If group
membership changes during the wait and the sleep ends by signal or
timeout (so autoremove_wake_function() does not run), finish_wait() is
skipped and snd_pcm_drain() returns with the entry still queued on that
stream's sleep list; a later wake_up() then walks a freed stack frame.
This is reachable by unlinking either the drained or the draining stream.
Unlike the close path (snd_pcm_drop() -> snd_pcm_post_stop()),
snd_pcm_unlink() never wakes the sleep queues. Wake every group member
under the group lock before the membership change, so a linked drainer is
released and drops its entry while the streams are still grouped.
The window was opened when snd_pcm_link_rwsem stopped being held across
the wait and the removal became conditional on group membership (see
Fixes). The later switch to finish_wait() kept that conditional removal,
so the signal/timeout case remained.
Fixes: f57f3df03a8e ("ALSA: pcm: More fine-grained PCM link locking")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Link: https://patch.msgid.link/A0705100-D10B-4286-9980-0142ABEEAD51@doyensec.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_timer_close_locked() marks an instance with SNDRV_TIMER_IFLG_DEAD
and returns early when the flag is already set, but the flag is never
cleared again. A completed close ends in remove_slave_links(), which
leaves timeri->timer NULL, so a second close is already harmless through
the timer == NULL path; the early return can only be reached by an
instance that was opened again in between. For such an instance the
close unlinks nothing, so snd_timer_instance_free() frees an object that
is still on timer->open_list_head, still on snd_timer_master_list if it
was opened with a slave key, still owns any adopted slaves, and still
holds its timer and module references.
snd_seq_timer_open() reopens an instance exactly like that: it retries
its fallback open on the same object after a failure that has already
run snd_timer_close_locked() internally. An unprivileged user with
access to /dev/snd/timer and /dev/snd/seq can force that failure, since
snd_timer_check_master() returns -EBUSY when a pending slave matches the
new master's (slave_class, slave_id) key and the target timer has
reached max_instances, and SNDRV_TIMER_IOCTL_SELECT with dev_class =
SNDRV_TIMER_CLASS_SLAVE keeps the caller-supplied dev_sclass, so a
sequencer queue's key can be forged. The freed instance is afterwards
dereferenced by any further snd_timer_open() on that timer, by
snd_timer_check_slave(), and by /proc/asound/timers, which faults on the
stale ti->owner pointer.
The flag only has to be visible while the close is in progress, which is
all its other users need. Clear it in remove_slave_links(), under the
same timer->lock that sets it, once the instance is off every list.
Fixes: da3039e91d1f ("ALSA: timer: Forcibly close timer instances at closing")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Link: https://patch.msgid.link/CA41AA48-75BF-45E9-A36D-3A5D2F124F60@doyensec.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_ump_attach_legacy_rawmidi() allocates the legacy conversion array
ump->out_cvts and, on the snd_rawmidi_new() error path, frees it with
kfree() but leaves ump->out_cvts pointing at the freed memory. When the
endpoint is later torn down, snd_ump_endpoint_free() frees ump->out_cvts
a second time, resulting in a double free.
The host snd-usb-audio driver attaches the legacy rawmidi for any USB
MIDI 2.0 (UMP) device, so a device that makes snd_rawmidi_new() fail
reaches this path on enumeration.
Clear ump->out_cvts after freeing it on the error path so it is not
freed again during teardown.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
Fixes: 33cd7630782d ("ALSA: ump: Export MIDI1 / UMP conversion helpers")
Reported-by: Federico Kirschbaum <federico.kirschbaum@xbow.com>
Reported-by: Baul Lee <baul.lee@xbow.com>
Cc: stable@vger.kernel.org
Signed-off-by: Baul Lee <baul.lee@xbow.com>
Link: https://patch.msgid.link/20260726051633.41206-1-baul.lee@xbow.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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A userspace-driven ALSA timer (SND_UTIMER) lets an unprivileged user set
the backing snd_timer's hardware resolution to an arbitrary 64-bit value
via SNDRV_TIMER_IOCTL_CREATE. snd_utimer_create() only rejects zero.
When such a timer is bound to a sequencer queue, initialize_timer()
computes the tick period as
tmr->ticks = 1000000000 / (r * freq);
where r is that user-controlled resolution and freq is the sequencer
update rate in Hz, clamped to MIN_FREQUENCY..MAX_FREQUENCY (10..6250).
A resolution of 2^63 makes the 64-bit product r * freq wrap to zero for
any even freq, including DEFAULT_FREQUENCY (1000), so the division faults
with a divide-by-zero.
The division runs under tmr->lock with interrupts disabled, so the oops
leaves the spinlock held and hangs the CPU. It is reachable by an
unprivileged user with access to /dev/snd/timer and /dev/snd/seq.
Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 7 UID: 1000 PID: 456 Comm: alsa_seq_utimer Not tainted 7.2.0-rc4+
RIP: 0010:initialize_timer.constprop.0+0x20a/0x2d0
snd_seq_timer_start+0x15e/0x2b0
snd_seq_control_queue+0x56f/0xba0
snd_seq_write+0x3e0/0x730
Reject an overflowing product with check_mul_overflow() and fall back to
a single tick, which also avoids feeding a wrapped-but-nonzero divisor
(e.g. 2^63 * 1000 mod 2^64 == 0, or other resolutions wrapping to a small
value) into the period computation.
Fixes: 37745918e0e7 ("ALSA: timer: Introduce virtual userspace-driven timers")
Cc: <stable@vger.kernel.org>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Link: https://patch.msgid.link/DF8A3844-AD5E-4B8A-9CFC-BD83C212BA38@doyensec.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_timer_close_locked() drains the closing instance's own in-flight
callback (IFLG_CALLBACK) before freeing it, but not its slaves'. When a
master instance is closed, remove_slave_links() clears each slave's
->timer; the slave's own close then reads timer == NULL and takes the
branch that skips the drain entirely (snd_timer_stop_slave() also no-ops
on a NULL timer). So a slave whose callback is still running when the
master is closed is freed underneath the live callback, leading to
use-after-free.
Drain the slaves too before remove_slave_links() severs them.
snd_timer_stop() has already taken this instance off the active list, so
no new slave callback can be queued. Take the slaves off the ack list so
a pending one can't fire either, then wait for any that is already in
flight.
Fixes: 37745918e0e7 ("ALSA: timer: Introduce virtual userspace-driven timers")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/D26598EB-DBF7-4D76-9F71-8E4BD59822D4@doyensec.com
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The userspace-driven timer (utimer) TRIGGER ioctl calls
snd_timer_interrupt() directly with no serialization, so two threads
triggering the same utimer can run snd_timer_interrupt() on one
snd_timer concurrently.
snd_timer_process_callbacks() drops timer->lock around each instance
callback and marks the in-flight callback with the single
SNDRV_TIMER_IFLG_CALLBACK bit; snd_timer_close_locked() waits on that
bit to drain an in-flight callback before freeing the instance. The bit
cannot represent two concurrent callbacks: when a second interrupt
re-queues an instance whose callback is still running, both run at once,
the first to finish clears the bit, and the close-path drain then frees
the instance (and its callback_data) while the other callback is still
live - a use-after-free reachable by any user able to open
/dev/snd/timer, both via a user timer instance and via a sequencer queue
timer bound to the utimer.
snd_timer_interrupt() sets IFLG_CALLBACK before dropping timer->lock, so
a concurrent interrupt already observes it under the lock. Skip
re-queuing an instance (and its slaves) to the ack/sack list while its
callback is in flight; the accumulated pticks are delivered on the next
tick, so no event is lost.
Fixes: 37745918e0e7 ("ALSA: timer: Introduce virtual userspace-driven timers")
Cc: stable@vger.kernel.org
Suggested-by: Takashi Iwai <tiwai@suse.de>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/6F9B6501-8E65-4265-B02C-7EFB240D1664@doyensec.com
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queue_delete() closes the queue timer, then frees it. snd_seq_timer_close()
clears q->timer->timeri. snd_use_lock_sync() then drains borrowers, and
snd_seq_timer_delete() frees q->timer.
A borrower can re-open the timer inside that window. A SET_QUEUE_CLIENT
that took a queueptr() use_lock reference before the queue was unlinked
runs snd_seq_timer_open() after the close. Open refuses re-open only while
timeri is set, and the close just cleared it, so it re-opens timeri.
snd_seq_timer_delete() does not close that instance. Its snd_seq_timer_stop()
is a no-op, because running was cleared first. So it frees q->timer with the
instance still live. The queue is freed next.
The instance stays on the global timer with callback_data pointing at the
freed queue. A non-owner START on the unlocked queue arms it. The next tick
derefs the freed queue in snd_seq_timer_interrupt().
Reachable by an unprivileged user with access to /dev/snd/seq. No CAP and
no queue ownership required.
Close any lingering instance in the destructor. There, ->timeri can no
longer change: the queue is unlinked and all use_lock borrowers have
drained, so no snd_seq_queue_use() can re-open it. Close it before clearing
q->timer. snd_timer_close() waits for any in-flight snd_seq_timer_interrupt()
to finish, and that callback still reads q->timer (via snd_seq_check_queue()),
so q->timer must stay valid until it drains.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Link: https://patch.msgid.link/422FDB81-2A68-47C7-A22D-2D3301E2E86D@doyensec.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Align file_operations initializers with tabs to match the standard
kernel coding style and improve readability.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Link: https://patch.msgid.link/20260708140624.562403-1-phucduc.bui@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_ctl_open() unconditionally overwrites the return value of
snd_card_file_add() with -ENODEV on failure, discarding the actual
error code.
Fix this by directly returning the original error code returned by
snd_card_file_add() (e.g. -ENOMEM or -ENODEV). This behavior is
consistent with the error handling used in other functions such as
snd_mixer_oss_open(), snd_hwdep_open(), snd_pcm_oss_open(), and others.
There is no functional change other than the returned error code in this
failure path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260708023540.6962-1-phucduc.bui@gmail.com
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When try_module_get() fails in snd_pcm_open(), the owning module is going
away and the device is no longer usable, so -EFAULT ("bad address") is the
wrong error. Return -ENODEV, matching the other unavailable-device paths
in this function(the NULL pcm check and the card->shutdown check).
This changes the errno reported to userspace on this rare race.
No other behaviour changes.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260707084506.718583-7-phucduc.bui@gmail.com
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When try_module_get() fails in snd_pcm_oss_open(), the owning module is
going away and the device is no longer usable, so -EFAULT ("bad address")
is the wrong error. Return -ENODEV, matching the other unavailable-device
paths in this function(the NULL pcm check and the card->shutdown check).
This changes the errno reported to userspace on this rare race.
No other behaviour changes.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260707084506.718583-6-phucduc.bui@gmail.com
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When try_module_get() fails in snd_mixer_oss_open(), the owning module is
going away and the device is no longer usable, so -EFAULT ("bad address")
is the wrong error. Return -ENODEV, matching the other unavailable-device
paths in this function(the NULL card check and the NULL mixer_oss check).
This changes the errno reported to userspace on this rare race.
No other behaviour changes.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260707084506.718583-5-phucduc.bui@gmail.com
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When try_module_get() fails in alloc_info_private(), the owning module is
going away and the device is no longer usable, so -EFAULT ("bad address")
is the wrong error. Return -ENODEV, matching the other -ENODEV path in the
same function.
This changes the errno reported to userspace on this rare race.
No other behaviour changes.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260707084506.718583-4-phucduc.bui@gmail.com
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When try_module_get() fails in snd_hwdep_open(), the owning module is
going away and the device is no longer usable, so -EFAULT ("bad address")
is the wrong error. Return -ENODEV, matching the other unavailable-device
paths in this function(the NULL hw check and the card->shutdown check).
This changes the errno reported to userspace on this rare race.
No other behaviour changes.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260707084506.718583-3-phucduc.bui@gmail.com
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When try_module_get() fails in snd_ctl_open(), the owning module is going
away and the device is no longer usable, so -EFAULT ("bad address") is the
wrong error. Return -ENODEV, matching the other unavailable-device paths
in this function(the NULL card check and the snd_card_file_add() failure).
This changes the errno reported to userspace on this rare race.
No other behaviour changes.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260707084506.718583-2-phucduc.bui@gmail.com
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Use ARRAY_SIZE(snd_minors) instead of SNDRV_OS_MINORS directly, for
consistency with snd_find_free_minor() and snd_unregister_device() in
the same file. No functional change.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Link: https://patch.msgid.link/20260707074556.569451-1-phucduc.bui@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The alsa_sound_init() function currently returns a hardcoded -EIO
if register_chrdev() fails, masking specific error codes from
__register_chrdev() such as -EINVAL, -ENOMEM, or -EBUSY.
Masking these failures under a generic -EIO makes system-level
diagnostics unnecessarily difficult. Propagating explicit error codes
from register_chrdev() is also an established convention widely
practiced across other subsystems.
Fix this by capturing and propagating the dynamic error code from
register_chrdev(). While at it, also assign the return value of
snd_info_init() to the 'err' variable instead of hardcoding -ENOMEM
to ensure consistency and future-proofing.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Link: https://patch.msgid.link/20260703103840.253527-1-phucduc.bui@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The previous conversion from nonseekable_open() to stream_open() retained
the existing error check.
Since stream_open() always returns 0, remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-8-phucduc.bui@gmail.com
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The previous conversion from nonseekable_open() to stream_open() retained
the existing error check.
Since stream_open() always returns 0, remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-7-phucduc.bui@gmail.com
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The previous conversion from nonseekable_open() to stream_open() retained
the existing error check.
Since stream_open() always returns 0, remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-6-phucduc.bui@gmail.com
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nonseekable_open() always returns 0, so the error check is unnecessary.
Remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-5-phucduc.bui@gmail.com
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nonseekable_open() always returns 0, so the error check is unnecessary.
Remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-4-phucduc.bui@gmail.com
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nonseekable_open() always returns 0, so the error check is unnecessary.
Remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-3-phucduc.bui@gmail.com
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|
The previous conversion from nonseekable_open() to stream_open() retained
the existing error check.
Since stream_open() always returns 0, remove the dead error handling path.
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260702084445.519669-2-phucduc.bui@gmail.com
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When a device gets disconnected, the driver waits until the all opened
file descriptors are closed before releasing the device. Although PCM
core emits an error to any further syscalls (except for close), some
applications don't notice the disconnected state because they mainly
access only via mmap, and it may block the device release
unnecessarily too long.
This patch is an attempt to improve the behavior by adding the
notification of the PCM disconnected state at mmap data faulting.
When the device is disconnected, it now returns VM_FAULT_SIGBUS, so
that the application can notice the invalid PCM state.
Reported-and-tested-by: Ai Chao <aichao@kylinos.cn>
Link: https://lore.kernel.org/20260615132657.2097213-1-aichao@kylinos.cn>
Link: https://patch.msgid.link/20260619150035.1560937-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_seq_event_dup() copies an incoming event into a pool cell and, in
the UMP-enabled build, clears the trailing cell->ump.raw.extra word that
the memcpy() did not cover. The guard deciding whether to clear it
compares the copied size against sizeof(cell->event):
memcpy(&cell->ump, event, size);
if (size < sizeof(cell->event))
cell->ump.raw.extra = 0;
For a legacy (non-UMP) event, size == sizeof(struct snd_seq_event) ==
sizeof(cell->event), so the condition is false and the extra word keeps
stale data. The cell pool is allocated with kvmalloc() (not zeroed) and
cells are reused via a free list, so that word holds uninitialised heap
or leftover event data.
When such a cell is delivered to a UMP client (client->midi_version > 0)
that set SNDRV_SEQ_FILTER_NO_CONVERT -- so the legacy event reaches it
unconverted -- snd_seq_read() reads it out as the larger struct
snd_seq_ump_event and copies the stale word to user space, a 4-byte
kernel heap infoleak to an unprivileged /dev/snd/seq client.
Compare against sizeof(cell->ump) instead, so the trailing word is zeroed
for every event shorter than the UMP cell.
Fixes: 46397622a3fa ("ALSA: seq: Add UMP support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
Link: https://patch.msgid.link/20260623233841.853326-1-sammiee5311@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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In snd_pcm_set_sync_per_card() the le32 value is written to an u32
instead of an __le32 pointer. Fix the following warning by fixing
the type:
sound/soc/soc-pcm.c:2166:9: warning: incorrect type in argument 7 (different base types)
sound/soc/soc-pcm.c:2166:9: expected int
sound/soc/soc-pcm.c:2166:9: got restricted snd_pcm_format_t
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Link: https://patch.msgid.link/20260617102943.893950-1-ben.dooks@codethink.co.uk
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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snd_compr_task_new() allocates the driver task before validating the
returned DMA buffers and reserving file descriptors. When either of
those later steps fails, the core frees its task wrapper and DMA-buffer
references without calling the driver's task_free() callback. Any
driver resources allocated by task_create() are therefore leaked.
The dual-fd allocation path also jumps to cleanup without storing the
negative get_unused_fd_flags() result in retval. Since retval still
contains the successful task_create() return value, TASK_CREATE can
incorrectly report success although the task was discarded.
Preserve the fd allocation errors and call task_free() when failure
occurs after a successful task_create() callback.
Fixes: 04177158cf98 ("ALSA: compress_offload: introduce accel operation mode")
Fixes: 3d3f43fab4cf ("ALSA: compress_offload: improve file descriptors installation for dma-buf")
Cc: stable@vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260615-alsa-compress-task-unwind-v1-1-39e8ad3ddb27@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Although we've covered the races around the timer object assignment
and release for timer instances, there are still races at starting or
stopping the timer instance. They refer to timeri->timer without
lock, hence they can still trigger UAFs.
For addressing it, this patch changes the existing slave_active_lock
spinlock to timeri_lock rwlock. It's a global rwlock applied as
read-lock when snd_timer_start() & co are called as well as
snd_timeri_timer_get() is called. In turn, the places where
timeri->timer is assigned or released are covered by the write-lock.
The patch replaces spinlock_irqsave with spinlock in a couple of
spaces because they are now already protected by timeri_lock, too.
Reported-by: Kyle Zeng <kylebot@openai.com>
Link: https://patch.msgid.link/20260614090714.773216-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Linus Torvalds
Aleksandr Nogikh
John Keeping
Takashi Iwai
HyeongJun An
Lorenzo Stoakes
Maciej Strozek
Norbert Szetei
Baul Lee
bui duc phuc
Ben Dooks
Cássio Gabriel