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When KCOV is enabled all functions get instrumented, unless
the __no_sanitize_coverage attribute is used. To prepare for
__no_sanitize_coverage being applied to __init functions, we have to
handle differences in how GCC's inline optimizations get resolved. For
arm this exposed several places where __init annotations were missing
but ended up being "accidentally correct". Fix these cases and force
several functions to be inline with __always_inline.
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Lee Jones <lee@kernel.org>
Reviewed-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20250717232519.2984886-5-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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When KCOV is enabled all functions get instrumented, unless
the __no_sanitize_coverage attribute is used. To prepare for
__no_sanitize_coverage being applied to __init functions, we
have to handle differences in how GCC's inline optimizations get
resolved. For mips this requires adding the __init annotation on
init_mips_clocksource().
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/r/20250717232519.2984886-9-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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Move a few kfence and debug_pagealloc related functions in hash_utils.c
and radix_pgtable.c to __init sections since these are only invoked once
by an __init function during system initialization.
i.e.
- hash_debug_pagealloc_alloc_slots()
- hash_kfence_alloc_pool()
- hash_kfence_map_pool()
The above 3 functions only gets called by __init htab_initialize().
- alloc_kfence_pool()
- map_kfence_pool()
The above 2 functions only gets called by __init radix_init_pgtable()
This should also help fix warning msgs like:
>> WARNING: modpost: vmlinux: section mismatch in reference:
hash_debug_pagealloc_alloc_slots+0xb0 (section: .text) ->
memblock_alloc_try_nid (section: .init.text)
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202504190552.mnFGs5sj-lkp@intel.com/
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20250717232519.2984886-8-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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To reduce stale data lifetimes, enable CONFIG_INIT_ON_FREE_DEFAULT_ON as
well. This matches the addition of CONFIG_STACKLEAK=y, which is doing
similar for stack memory.
Link: https://lore.kernel.org/r/20250717232519.2984886-13-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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Since we can wipe the stack with both Clang and GCC plugins, enable this
for the "hardening.config" for wider testing.
Link: https://lore.kernel.org/r/20250717232519.2984886-12-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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In preparation for Clang stack depth tracking for KSTACK_ERASE,
split the stackleak-specific cflags out of GCC_PLUGINS_CFLAGS into
KSTACK_ERASE_CFLAGS.
Link: https://lore.kernel.org/r/20250717232519.2984886-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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The Clang stack depth tracking implementation has a fixed name for
the stack depth tracking callback, "__sanitizer_cov_stack_depth", so
rename the GCC plugin function to match since the plugin has no external
dependencies on naming.
Link: https://lore.kernel.org/r/20250717232519.2984886-2-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:
- Add the new top-level CONFIG_KSTACK_ERASE option which will be
implemented either with the stackleak GCC plugin, or with the Clang
stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
for what it does rather than what it protects against), but leave as
many of the internals alone as possible to avoid even more churn.
While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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Add KUnit tests for the seq_buf API to ensure its correctness and
prevent future regressions, covering the following functions:
- seq_buf_init()
- DECLARE_SEQ_BUF()
- seq_buf_clear()
- seq_buf_puts()
- seq_buf_putc()
- seq_buf_printf()
- seq_buf_get_buf()
- seq_buf_commit()
$ tools/testing/kunit/kunit.py run seq_buf
=================== seq_buf (9 subtests) ===================
[PASSED] seq_buf_init_test
[PASSED] seq_buf_declare_test
[PASSED] seq_buf_clear_test
[PASSED] seq_buf_puts_test
[PASSED] seq_buf_puts_overflow_test
[PASSED] seq_buf_putc_test
[PASSED] seq_buf_printf_test
[PASSED] seq_buf_printf_overflow_test
[PASSED] seq_buf_get_buf_commit_test
===================== [PASSED] seq_buf =====================
Link: https://lore.kernel.org/r/20250717085156.work.363-kees@kernel.org
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <kees@kernel.org>
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The two str_has_prefix() and strstarts() are about the same
with a slight difference on what they return. Group them in
the header.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250711085514.1294428-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook <kees@kernel.org>
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It seems the Clang can see through OPTIMIZER_HIDE_VAR when the constant
is coming from sizeof. Adding "volatile" back to these variables solves
this false positive without reintroducing the issues that originally led
to switching to OPTIMIZER_HIDE_VAR in the first place[1].
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://github.com/ClangBuiltLinux/linux/issues/2075 [1]
Cc: Jannik Glückert <jannik.glueckert@gmail.com>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Fixes: 6ee149f61bcc ("kunit/fortify: Replace "volatile" with OPTIMIZER_HIDE_VAR()")
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250628234034.work.800-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Use the new TRAILING_OVERLAP() helper to fix a dozen instances of
the following type of warning:
drivers/acpi/nfit/intel.c:692:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/aF7pF4kej8VQapyR@kspp
Signed-off-by: Kees Cook <kees@kernel.org>
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Add new TRAILING_OVERLAP() helper macro to create a union between
a flexible-array member (FAM) and a set of members that would
otherwise follow it. This overlays the trailing members onto the
FAM while preserving the original memory layout.
Co-developed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/aFG8gEwKXAWWIvX0@kspp
Signed-off-by: Kees Cook <kees@kernel.org>
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Convert mux_control_ops to a flexible array member at the end of the
mux_chip struct and add the __counted_by() compiler attribute to
improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.
Use struct_size() to calculate the number of bytes to allocate for a new
mux chip and to remove the following Coccinelle/coccicheck warning:
WARNING: Use struct_size
Use size_add() to safely add any extra bytes.
No functional changes intended.
Link: https://github.com/KSPP/linux/issues/83
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20250610104106.1948-2-thorsten.blum@linux.dev
Signed-off-by: Kees Cook <kees@kernel.org>
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As we always iterate through the entire die_map when expanding
type strings, recursively processing referenced types in
type_expand_child() is not actually necessary. Furthermore,
the type_string kABI rule added in commit c9083467f7b9
("gendwarfksyms: Add a kABI rule to override type strings") can
fail to override type strings for structures due to a missing
kabi_get_type_string() check in this function.
Fix the issue by dropping the unnecessary recursion and moving
the override check to type_expand(). Note that symbol versions
are otherwise unchanged with this patch.
Fixes: c9083467f7b9 ("gendwarfksyms: Add a kABI rule to override type strings")
Reported-by: Giuliano Procida <gprocida@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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This hides excessive warnings, as nobody builds with W=2.
Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1")
Fixes: 7d95680d64ac ("scripts/misc-check: check unnecessary #include <linux/export.h> when W=1")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
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In preparation for needing to shift NVMe passthrough to always use
task_work for polled IO completions, ensure that those are suitably
run at exit time. See commit:
9ce6c9875f3e ("nvme: always punt polled uring_cmd end_io work to task_work")
for details on why that is necessary.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Currently NVMe uring_cmd completions will complete locally, if they are
polled. This is done because those completions are always invoked from
task context. And while that is true, there's no guarantee that it's
invoked under the right ring context, or even task. If someone does
NVMe passthrough via multiple threads and with a limited number of
poll queues, then ringA may find completions from ringB. For that case,
completing the request may not be sound.
Always just punt the passthrough completions via task_work, which will
redirect the completion, if needed.
Cc: stable@vger.kernel.org
Fixes: 585079b6e425 ("nvme: wire up async polling for io passthrough commands")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If an exiting non-autoreaping task has already passed exit_notify() and
calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent
or debugger right after unlock_task_sighand().
If a concurrent posix_cpu_timer_del() runs at that moment, it won't be
able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or
lock_task_sighand() will fail.
Add the tsk->exit_state check into run_posix_cpu_timers() to fix this.
This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because
exit_task_work() is called before exit_notify(). But the check still
makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail
anyway in this case.
Cc: stable@vger.kernel.org
Reported-by: Benoît Sevens <bsevens@google.com>
Fixes: 0bdd2ed4138e ("sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand()")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If peeking a bunch of buffers, normally io_ring_buffers_peek() will
truncate the end buffer. This isn't optimal as presumably more data will
be arriving later, and hence it's better to stop with the last full
buffer rather than truncate the end buffer.
Cc: stable@vger.kernel.org
Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers")
Reported-by: Christian Mazakas <christian.mazakas@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Stephen Rothwell reports htmldocs warning on ublk docs:
Documentation/block/ublk.rst:414: ERROR: Unexpected indentation. [docutils]
Fix the warning by separating sublists of auto buffer registration
fallback behavior from their appropriate parent list item.
Fixes: ff20c516485e ("ublk: document auto buffer registration(UBLK_F_AUTO_BUF_REG)")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20250612132638.193de386@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20250613023857.15971-1-bagasdotme@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This driver uses a mixture of ways to get the size of a PTE,
tegra_smmu_set_pde() did it as sizeof(*pd) which became wrong when pd
switched to a struct tegra_pd.
Switch pd back to a u32* in tegra_smmu_set_pde() so the sizeof(*pd)
returns 4.
Fixes: 50568f87d1e2 ("iommu/terga: Do not use struct page as the handle for as->pd memory")
Reported-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Closes: https://lore.kernel.org/all/62e7f7fe-6200-4e4f-ad42-d58ad272baa6@tecnico.ulisboa.pt/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Link: https://lore.kernel.org/r/0-v1-da7b8b3d57eb+ce-iommu_terga_sizeof_jgg@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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Similarly to 26064d3e2b4d ("block: fix adding folio to bio"), if
we attempt to add a folio that is larger than 4GB, we'll silently
truncate the offset and len. Widen the parameters to size_t, assert
that the length is less than 4GB and set the first page that contains
the interesting data rather than the first page of the folio.
Fixes: 26db5ee15851 (block: add a bvec_set_folio helper)
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20250612144255.2850278-1-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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It is possible for physically contiguous folios to have discontiguous
struct pages if SPARSEMEM is enabled and SPARSEMEM_VMEMMAP is not.
This is correctly handled by folio_page_idx(), so remove this open-coded
implementation.
Fixes: 640d1930bef4 (block: Add bio_for_each_folio_all())
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20250612144126.2849931-1-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Removes MSI-X from the interrupt request path, as the DMA engine used by
the SPI controller does not support MSI-X interrupts.
Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
Link: https://patch.msgid.link/20250612023059.71726-1-thangaraj.s@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
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Nested file systems, that is those which invoke call_mmap() within their
own f_op->mmap() handlers, may encounter underlying file systems which
provide the f_op->mmap_prepare() hook introduced by commit c84bf6dd2b83
("mm: introduce new .mmap_prepare() file callback").
We have a chicken-and-egg scenario here - until all file systems are
converted to using .mmap_prepare(), we cannot convert these nested
handlers, as we can't call f_op->mmap from an .mmap_prepare() hook.
So we have to do it the other way round - invoke the .mmap_prepare() hook
from an .mmap() one.
in order to do so, we need to convert VMA state into a struct vm_area_desc
descriptor, invoking the underlying file system's f_op->mmap_prepare()
callback passing a pointer to this, and then setting VMA state accordingly
and safely.
This patch achieves this via the compat_vma_mmap_prepare() function, which
we invoke from call_mmap() if f_op->mmap_prepare() is specified in the
passed in file pointer.
We place the fundamental logic into mm/vma.h where VMA manipulation
belongs. We also update the VMA userland tests to accommodate the
changes.
The compat_vma_mmap_prepare() function and its associated machinery is
temporary, and will be removed once the conversion of file systems is
complete.
We carefully place this code so it can be used with CONFIG_MMU and also
with cutting edge nommu silicon.
[akpm@linux-foundation.org: export compat_vma_mmap_prepare tp fix build]
[lorenzo.stoakes@oracle.com: remove unused declarations]
Link: https://lkml.kernel.org/r/ac3ae324-4c65-432a-8c6d-2af988b18ac8@lucifer.local
Link: https://lkml.kernel.org/r/20250609165749.344976-1-lorenzo.stoakes@oracle.com
Fixes: c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback").
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Closes: https://lore.kernel.org/linux-mm/CAG48ez04yOEVx1ekzOChARDDBZzAKwet8PEoPM4Ln3_rk91AzQ@mail.gmail.com/
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently, cached directory contents were not reused across subsequent
'ls' operations because the cache validity check relied on comparing
the ctx pointer, which changes with each readdir invocation. As a
result, the cached dir entries was not marked as valid and the cache was
not utilized for subsequent 'ls' operations.
This change uses the file pointer, which remains consistent across all
readdir calls for a given directory instance, to associate and validate
the cache. As a result, cached directory contents can now be
correctly reused, improving performance for repeated directory listings.
Performance gains with local windows SMB server:
Without the patch and default actimeo=1:
1000 directory enumeration operations on dir with 10k files took 135.0s
With this patch and actimeo=0:
1000 directory enumeration operations on dir with 10k files took just 5.1s
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
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Customer reported that one of their applications started failing to
open files with STATUS_INSUFFICIENT_RESOURCES due to NetApp server
hitting the maximum number of opens to same file that it would allow
for a single client connection.
It turned out the client was failing to reuse open handles with
deferred closes because matching ->f_flags directly without masking
off O_CREAT|O_EXCL|O_TRUNC bits first broke the comparision and then
client ended up with thousands of deferred closes to same file. Those
bits are already satisfied on the original open, so no need to check
them against existing open handles.
Reproducer:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <pthread.h>
#define NR_THREADS 4
#define NR_ITERATIONS 2500
#define TEST_FILE "/mnt/1/test/dir/foo"
static char buf[64];
static void *worker(void *arg)
{
int i, j;
int fd;
for (i = 0; i < NR_ITERATIONS; i++) {
fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_APPEND, 0666);
for (j = 0; j < 16; j++)
write(fd, buf, sizeof(buf));
close(fd);
}
}
int main(int argc, char *argv[])
{
pthread_t t[NR_THREADS];
int fd;
int i;
fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_TRUNC, 0666);
close(fd);
memset(buf, 'a', sizeof(buf));
for (i = 0; i < NR_THREADS; i++)
pthread_create(&t[i], NULL, worker, NULL);
for (i = 0; i < NR_THREADS; i++)
pthread_join(t[i], NULL);
return 0;
}
Before patch:
$ mount.cifs //srv/share /mnt/1 -o ...
$ mkdir -p /mnt/1/test/dir
$ gcc repro.c && ./a.out
...
number of opens: 1391
After patch:
$ mount.cifs //srv/share /mnt/1 -o ...
$ mkdir -p /mnt/1/test/dir
$ gcc repro.c && ./a.out
...
number of opens: 1
Cc: linux-cifs@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jay Shin <jaeshin@redhat.com>
Cc: Pierguido Lambri <plambri@redhat.com>
Fixes: b8ea3b1ff544 ("smb: enable reuse of deferred file handles for write operations")
Acked-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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In case the BO is in iomem, we can't simply take the vaddr and write to
it. Instead, prepare a separate buffer that is later copied into io
memory. Right now it's just a few words that could be using
xe_map_write32(), but the intention is to grow the WA BB for other
uses.
Fixes: 617d824c5323 ("drm/xe: Add WA BB to capture active context utilization")
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://lore.kernel.org/r/20250604-wa-bb-fix-v1-1-0dfc5dafcef0@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit ef48715b2d3df17c060e23b9aa636af3d95652f8)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
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Add test_rss_default_context_rule() to verify that ntuple rules can
correctly direct traffic to the default RSS context (context 0).
The test creates two ntuple rules with explicit location priorities:
- A high-priority rule (loc 0) directing specific port traffic to
context 0.
- A low-priority rule (loc 1) directing all other TCP traffic to context
1.
This validates that:
1. Rules targeting the default context function properly.
2. Traffic steering works as expected when mixing default and
additional RSS contexts.
The test was written by AI, and reviewed by humans.
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20250612071958.1696361-3-gal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Context 0 (default context) always exists, there is no need to check
whether it exists or not when adding a flow steering rule.
The existing check fails when creating a flow steering rule for context
0 as it is not stored in the rss_ctx xarray.
For example:
$ ethtool --config-ntuple eth2 flow-type tcp4 dst-ip 194.237.147.23 dst-port 19983 context 0 loc 618
rmgr: Cannot insert RX class rule: Invalid argument
Cannot insert classification rule
An example usecase for this could be:
- A high-priority rule (loc 0) directing specific port traffic to
context 0.
- A low-priority rule (loc 1) directing all other TCP traffic to context
1.
This is a user-visible regression that was caught in our testing
environment, it was not reported by a user yet.
Fixes: de7f7582dff2 ("net: ethtool: prevent flow steering to RSS contexts which don't exist")
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/20250612071958.1696361-2-gal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Before the cited commit, the kernel unconditionally embedded SCM
credentials to skb for embryo sockets even when both the sender
and listener disabled SO_PASSCRED and SO_PASSPIDFD.
Now, the credentials are added to skb only when configured by the
sender or the listener.
However, as reported in the link below, it caused a regression for
some programs that assume credentials are included in every skb,
but sometimes not now.
The only problematic scenario would be that a socket starts listening
before setting the option. Then, there will be 2 types of non-small
race window, where a client can send skb without credentials, which
the peer receives as an "invalid" message (and aborts the connection
it seems ?):
Client Server
------ ------
s1.listen() <-- No SO_PASS{CRED,PIDFD}
s2.connect()
s2.send() <-- w/o cred
s1.setsockopt(SO_PASS{CRED,PIDFD})
s2.send() <-- w/ cred
or
Client Server
------ ------
s1.listen() <-- No SO_PASS{CRED,PIDFD}
s2.connect()
s2.send() <-- w/o cred
s3, _ = s1.accept() <-- Inherit cred options
s2.send() <-- w/o cred but not set yet
s3.setsockopt(SO_PASS{CRED,PIDFD})
s2.send() <-- w/ cred
It's unfortunate that buggy programs depend on the behaviour,
but let's restore the previous behaviour.
Fixes: 3f84d577b79d ("af_unix: Inherit sk_flags at connect().")
Reported-by: Jacek Łuczak <difrost.kernel@gmail.com>
Closes: https://lore.kernel.org/all/68d38b0b-1666-4974-85d4-15575789c8d4@gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Tested-by: Christian Heusel <christian@heusel.eu>
Tested-by: André Almeida <andrealmeid@igalia.com>
Tested-by: Jacek Łuczak <difrost.kernel@gmail.com>
Link: https://patch.msgid.link/20250611202758.3075858-1-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzkaller created an IPv6 route from a malformed packet, which has
a prefix len > 128, triggering the splat below. [0]
This is a similar issue fixed by commit 586ceac9acb7 ("ipv6: Restore
fib6_config validation for SIOCADDRT.").
The cited commit removed fib6_config validation from some callers
of ip6_add_route().
Let's move the validation back to ip6_route_add() and
ip6_route_multipath_add().
[0]:
UBSAN: array-index-out-of-bounds in ./include/net/ipv6.h:616:34
index 20 is out of range for type '__u8 [16]'
CPU: 1 UID: 0 PID: 7444 Comm: syz.0.708 Not tainted 6.16.0-rc1-syzkaller-g19272b37aa4f #0 PREEMPT
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80078a80>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:132
[<ffffffff8000327a>] show_stack+0x30/0x3c arch/riscv/kernel/stacktrace.c:138
[<ffffffff80061012>] __dump_stack lib/dump_stack.c:94 [inline]
[<ffffffff80061012>] dump_stack_lvl+0x12e/0x1a6 lib/dump_stack.c:120
[<ffffffff800610a6>] dump_stack+0x1c/0x24 lib/dump_stack.c:129
[<ffffffff8001c0ea>] ubsan_epilogue+0x14/0x46 lib/ubsan.c:233
[<ffffffff819ba290>] __ubsan_handle_out_of_bounds+0xf6/0xf8 lib/ubsan.c:455
[<ffffffff85b363a4>] ipv6_addr_prefix include/net/ipv6.h:616 [inline]
[<ffffffff85b363a4>] ip6_route_info_create+0x8f8/0x96e net/ipv6/route.c:3793
[<ffffffff85b635da>] ip6_route_add+0x2a/0x1aa net/ipv6/route.c:3889
[<ffffffff85b02e08>] addrconf_prefix_route+0x2c4/0x4e8 net/ipv6/addrconf.c:2487
[<ffffffff85b23bb2>] addrconf_prefix_rcv+0x1720/0x1e62 net/ipv6/addrconf.c:2878
[<ffffffff85b92664>] ndisc_router_discovery+0x1a06/0x3504 net/ipv6/ndisc.c:1570
[<ffffffff85b99038>] ndisc_rcv+0x500/0x600 net/ipv6/ndisc.c:1874
[<ffffffff85bc2c18>] icmpv6_rcv+0x145e/0x1e0a net/ipv6/icmp.c:988
[<ffffffff85af6798>] ip6_protocol_deliver_rcu+0x18a/0x1976 net/ipv6/ip6_input.c:436
[<ffffffff85af8078>] ip6_input_finish+0xf4/0x174 net/ipv6/ip6_input.c:480
[<ffffffff85af8262>] NF_HOOK include/linux/netfilter.h:317 [inline]
[<ffffffff85af8262>] NF_HOOK include/linux/netfilter.h:311 [inline]
[<ffffffff85af8262>] ip6_input+0x16a/0x70c net/ipv6/ip6_input.c:491
[<ffffffff85af8dcc>] ip6_mc_input+0x5c8/0x1268 net/ipv6/ip6_input.c:588
[<ffffffff85af6112>] dst_input include/net/dst.h:469 [inline]
[<ffffffff85af6112>] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
[<ffffffff85af6112>] NF_HOOK include/linux/netfilter.h:317 [inline]
[<ffffffff85af6112>] NF_HOOK include/linux/netfilter.h:311 [inline]
[<ffffffff85af6112>] ipv6_rcv+0x5ae/0x6e0 net/ipv6/ip6_input.c:309
[<ffffffff85087e84>] __netif_receive_skb_one_core+0x106/0x16e net/core/dev.c:5977
[<ffffffff85088104>] __netif_receive_skb+0x2c/0x144 net/core/dev.c:6090
[<ffffffff850883c6>] netif_receive_skb_internal net/core/dev.c:6176 [inline]
[<ffffffff850883c6>] netif_receive_skb+0x1aa/0xbf2 net/core/dev.c:6235
[<ffffffff8328656e>] tun_rx_batched.isra.0+0x430/0x686 drivers/net/tun.c:1485
[<ffffffff8329ed3a>] tun_get_user+0x2952/0x3d6c drivers/net/tun.c:1938
[<ffffffff832a21e0>] tun_chr_write_iter+0xc4/0x21c drivers/net/tun.c:1984
[<ffffffff80b9b9ae>] new_sync_write fs/read_write.c:593 [inline]
[<ffffffff80b9b9ae>] vfs_write+0x56c/0xa9a fs/read_write.c:686
[<ffffffff80b9c2be>] ksys_write+0x126/0x228 fs/read_write.c:738
[<ffffffff80b9c42e>] __do_sys_write fs/read_write.c:749 [inline]
[<ffffffff80b9c42e>] __se_sys_write fs/read_write.c:746 [inline]
[<ffffffff80b9c42e>] __riscv_sys_write+0x6e/0x94 fs/read_write.c:746
[<ffffffff80076912>] syscall_handler+0x94/0x118 arch/riscv/include/asm/syscall.h:112
[<ffffffff8637e31e>] do_trap_ecall_u+0x396/0x530 arch/riscv/kernel/traps.c:341
[<ffffffff863a69e2>] handle_exception+0x146/0x152 arch/riscv/kernel/entry.S:197
Fixes: fa76c1674f2e ("ipv6: Move some validation from ip6_route_info_create() to rtm_to_fib6_config().")
Reported-by: syzbot+4c2358694722d304c44e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6849b8c3.a00a0220.1eb5f5.00f0.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611193551.2999991-1-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
netdevsim supports netpoll. Make sure we don't call napi_complete()
from it, since it may not be scheduled. Breno reports hitting a
warning in napi_complete_done():
WARNING: CPU: 14 PID: 104 at net/core/dev.c:6592 napi_complete_done+0x2cc/0x560
__napi_poll+0x2d8/0x3a0
handle_softirqs+0x1fe/0x710
This is presumably after netpoll stole the SCHED bit prematurely.
Reported-by: Breno Leitao <leitao@debian.org>
Fixes: 3762ec05a9fb ("netdevsim: add NAPI support")
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250611174643.2769263-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Check for if ida_alloc() or rhashtable_lookup_get_insert_fast() fails.
Fixes: 17e0accac577 ("net/mlx5: HWS, support complex matchers")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Link: https://patch.msgid.link/aEmBONjyiF6z5yCV@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The veth peer device is RCU protected, but when the peer device gets
deleted (veth_dellink) then the pointer is assigned NULL (via
RCU_INIT_POINTER).
This patch adds a necessary NULL check in veth_xdp_rcv when accessing
the veth peer net_device.
This fixes a bug introduced in commit dc82a33297fc ("veth: apply qdisc
backpressure on full ptr_ring to reduce TX drops"). The bug is a race
and only triggers when having inflight packets on a veth that is being
deleted.
Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Closes: https://lore.kernel.org/all/fecfcad0-7a16-42b8-bff2-66ee83a6e5c4@linux.dev/
Reported-by: syzbot+c4c7bf27f6b0c4bd97fe@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/683da55e.a00a0220.d8eae.0052.GAE@google.com/
Fixes: dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to reduce TX drops")
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://patch.msgid.link/174964557873.519608.10855046105237280978.stgit@firesoul
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
This function is no longer used after the four prior fixes.
Given all prior uses were wrong, it seems better to remove it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in TBF, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://patch.msgid.link/20250611111515.1983366-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 0c8d13ac9607 ("net: sched: red: delay destroying child qdisc on replace")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 7b8e0b6e6599 ("net: sched: prio: delay destroying child qdiscs on change")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch.
We want to make sure ctl->perturb_period * HZ will not overflow
and is positive.
Tested:
tc qd add dev lo root sfq perturb -10 # negative value : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
When performing a non-exact phy_caps lookup, we are looking for a
supported mode that matches as closely as possible the passed speed/duplex.
Blamed patch broke that logic by returning a match too early in case
the caller asks for half-duplex, as a full-duplex linkmode may match
first, and returned as a non-exact match without even trying to mach on
half-duplex modes.
Reported-by: Jijie Shao <shaojijie@huawei.com>
Closes: https://lore.kernel.org/netdev/20250603102500.4ec743cf@fedora/T/#m22ed60ca635c67dc7d9cbb47e8995b2beb5c1576
Tested-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Fixes: fc81e257d19f ("net: phy: phy_caps: Allow looking-up link caps based on speed and duplex")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20250606094321.483602-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The sqpoll thread is dereferenced with rcu read protection in one place,
so it needs to be annotated as an __rcu type, and should consistently
use rcu helpers for access and assignment to make sparse happy.
Since most of the accesses occur under the sqd->lock, we can use
rcu_dereference_protected() without declaring an rcu read section.
Provide a simple helper to get the thread from a locked context.
Fixes: ac0b8b327a5677d ("io_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250611205343.1821117-1-kbusch@meta.com
[axboe: fold in fix for register.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
After commit a934a57a42f64a4 ("scripts/misc-check: check missing #include
<linux/export.h> when W=1") and 7d95680d64ac8e836c ("scripts/misc-check:
check unnecessary #include <linux/export.h> when W=1"), we get some build
warnings with W=1:
init/main.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
init/initramfs.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
So fix these build warnings for the init code.
Link: https://lkml.kernel.org/r/20250608141235.155206-1-chenhuacai@loongson.cn
Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
I have been actively contributing to mTHP and reviewing related patches
for an extended period, and I would like to continue supporting patch
reviews.
Link: https://lkml.kernel.org/r/20250609002442.1856-1-21cnbao@gmail.com
Signed-off-by: Barry Song <baohua@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Dev Jain <dev.jain@arm.com>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Nico Pache <npache@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In
riocm_cdev_ioctl(RIO_CM_CHAN_SEND)
-> cm_chan_msg_send()
-> riocm_ch_send()
cm_chan_msg_send() checks that userspace didn't send too much data but
riocm_ch_send() failed to check that userspace sent sufficient data. The
result is that riocm_ch_send() can write to fields in the rio_ch_chan_hdr
which were outside the bounds of the space which cm_chan_msg_send()
allocated.
Address this by teaching riocm_ch_send() to check that the entire
rio_ch_chan_hdr was copied in from userspace.
Reported-by: maher azz <maherazz04@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a
parallel reclaim leaving stale TLB entries") described a theoretical race
as such:
"""
Nadav Amit identified a theoretical race between page reclaim and mprotect
due to TLB flushes being batched outside of the PTL being held.
He described the race as follows:
CPU0 CPU1
---- ----
user accesses memory using RW PTE
[PTE now cached in TLB]
try_to_unmap_one()
==> ptep_get_and_clear()
==> set_tlb_ubc_flush_pending()
mprotect(addr, PROT_READ)
==> change_pte_range()
==> [ PTE non-present - no flush ]
user writes using cached RW PTE
...
try_to_unmap_flush()
The same type of race exists for reads when protecting for PROT_NONE and
also exists for operations that can leave an old TLB entry behind such as
munmap, mremap and madvise.
"""
The solution was to introduce flush_tlb_batched_pending() and call it
under the PTL from mprotect/madvise/munmap/mremap to complete any pending
tlb flushes.
However, while madvise_free_pte_range() and
madvise_cold_or_pageout_pte_range() were both retro-fitted to call
flush_tlb_batched_pending() immediately after initially acquiring the PTL,
they both temporarily release the PTL to split a large folio if they
stumble upon one. In this case, where re-acquiring the PTL
flush_tlb_batched_pending() must be called again, but it previously was
not. Let's fix that.
There are 2 Fixes: tags here: the first is the commit that fixed
madvise_free_pte_range(). The second is the commit that added
madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the
faulty pattern from madvise_free_pte_range().
This is a theoretical bug discovered during code review.
Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com
Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries")
Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
While an OOM failure in commit_merge() isn't really feasible due to the
allocation which might fail (a maple tree pre-allocation) being 'too small
to fail', we do need to handle this case correctly regardless.
In vma_merge_existing_range(), we can theoretically encounter failures
which result in an OOM error in two ways - firstly dup_anon_vma() might
fail with an OOM error, and secondly commit_merge() failing, ultimately,
to pre-allocate a maple tree node.
The abort logic for dup_anon_vma() resets the VMA iterator to the initial
range, ensuring that any logic looping on this iterator will correctly
proceed to the next VMA.
However the commit_merge() abort logic does not do the same thing. This
resulted in a syzbot report occurring because mlockall() iterates through
VMAs, is tolerant of errors, but ended up with an incorrect previous VMA
being specified due to incorrect iterator state.
While making this change, it became apparent we are duplicating logic -
the logic introduced in commit 41e6ddcaa0f1 ("mm/vma: add give_up_on_oom
option on modify/merge, use in uffd release") duplicates the
vmg->give_up_on_oom check in both abort branches.
Additionally, we observe that we can perform the anon_dup check safely on
dup_anon_vma() failure, as this will not be modified should this call
fail.
Finally, we need to reset the iterator in both cases, so now we can simply
use the exact same code to abort for both.
We remove the VM_WARN_ON(err != -ENOMEM) as it would be silly for this to
be otherwise and it allows us to implement the abort check more neatly.
Link: https://lkml.kernel.org/r/20250606125032.164249-1-lorenzo.stoakes@oracle.com
Fixes: 47b16d0462a4 ("mm: abort vma_modify() on merge out of memory failure")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: syzbot+d16409ea9ecc16ed261a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/6842cc67.a00a0220.29ac89.003b.GAE@google.com/
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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