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cpufreq_policy_alloc() allocates policy->cpus with alloc_cpumask_var(),
i.e. without __GFP_ZERO, unlike the sibling related_cpus and real_cpus
masks. With CONFIG_CPUMASK_OFFSTACK=y the mask is a separate
kmalloc_node() allocation, so its bitmap holds whatever the slab allocator
left behind:
cpufreq_online()
cpufreq_policy_alloc()
alloc_cpumask_var(&policy->cpus) /* bitmap is uninitialized */
kobject_init_and_add() /* policy%u/ appears in sysfs */
cpufreq_policy_online()
cpumask_copy(policy->cpus, cpumask_of(cpu)) /* first valid value */
This leaves a window in which the sysfs attributes are already reachable
while policy->cpus is still garbage. show()/store() gate on
policy_is_inactive(), i.e. cpumask_empty(policy->cpus), so a non-zero
bitmap makes them run the attribute callbacks on a policy that is not
initialized yet.
Fix this by using zalloc_cpumask_var() for policy->cpus.
Fixes: 2fc3384dc75b ("cpufreq: Initialize policy->kobj while allocating policy")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20260901143635.4106960-1-zhongqiu.han@oss.qualcomm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Since commit e645535a954a ("tracing: Add option to use memmapped
memory for trace boot instance") changed trace_array_get_by_name() to
trace_array_create_systems(), enable_instances() does not reuse the
same name instance. Therefore, if an administrator mistakenly specifies
multiple `trace_instance=` options with duplicate names, all are
created but only the first is accessible via tracefs.
Check whether an instance with the same name already exists before
creating a new one, and reject duplicates with a warning.
Link: https://patch.msgid.link/178847790399.283263.5313150997200138426.stgit@devnote2
Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Pull smb server fixes from Namjae Jeon:
- Fix a tree connection use-after-free in smb2_tree_connect() by
balancing references across concurrent connect, disconnect, and
session logoff paths.
- Validate source and target ranges in COPYCHUNK requests before range
locking and copy operations.
- Fix an oplock break notification UAF by acquiring a connection
reference under ksmbd_inode lock and releasing it after the
notification work completes.
- Fix the sparc build by using an unsigned int for the atomic work
state, ensuring xchg() uses a supported four-byte operation.
* tag 'ksmbd-for-7.3-rc2-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smb:
ksmbd: fix tree connection use-after-free in smb2_tree_connect()
ksmbd: validate COPYCHUNK source and target ranges
ksmbd: fix use-after-free in oplock break notification
ksmbd: fix sparc build with atomic work state
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KVM: s390: Misc fixes
A bunch of fixes to bugs found in the past weeks.
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Pull probes fixes from Masami Hiramatsu:
- Protect kprobe_blacklist with RCU
RCU-protect kprobe_blacklist and use kfree_rcu() to prevent UAF races
during module unloading and enable safe atomic lookups.
- Fix multi-probe field use-after-free
Duplicate field and type strings on trace_probe_event to prevent UAF
when freeing primary probe
- Fix probe BTF member lookup:
Check the containing inner struct/union kflag when resolving
anonymous members to ensure correct bitfield offset calculation
Prevent unnamed bitfields from being pushed to anon_stack in
btf_find_struct_member(), avoiding false lookup errors
Fix code block indentation in get_bitoffset_of_field()
- uprobes error pointer safety
Guard free_trace_uprobe() with IS_ERR_OR_NULL() to avoid crashing
during automatic cleanup when an error pointer is returned
* tag 'probes-fixes-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
kprobes: Protect kprobe_blacklist with RCU
tracing/probes: Fix use-after-free on field name/type of events with multiple probes
tracing/probes: Fix code indent in get_bitoffset_of_field()
tracing/probes: Fix BTF kflag check for anonymous struct member access
tracing/probes: Fix anon_stack check for unnamed bitfields in btf_find_struct_member
uprobes: guard trace cleanup against error pointers
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Pull pmdomain and cpuidle fixes from Ulf Hansson:
"pmdomain providers:
- mediatek: Fix Kconfig for Airoha power domains
- qcom: Revert adding the missing power domains for Eliza
cpuidle:
- psci: Fix support for probe deferral by dropping the faux device
- dt_idle_genpd: Free the original name allocation"
* tag 'pmdomain-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/linux-pm:
cpuidle: dt_idle_genpd: kfree() the original name allocation
pmdomain: airoha: fix unselectable AIROHA_CPU_PM_DOMAIN kconfig
cpuidle: psci: Fix support for probe deferral by dropping the faux device
Revert "pmdomain: qcom: rpmhpd: Add missing MXC and MMCX power domains for Eliza"
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cpufreq_policy_alloc() initializes policy->rwsem after
kobject_init_and_add() has created the policy sysfs directory and its
default attributes. A sysfs access can therefore reach a policy callback
before the semaphore has been initialized.
Initialize policy->rwsem before publishing the policy kobject so sysfs
callbacks always see an initialized semaphore.
Fixes: 2fc3384dc75b ("cpufreq: Initialize policy->kobj while allocating policy")
Cc: All Applicable <stable@vger.kernel.org>
Link: https://lore.kernel.org/all/20260830155301.2713780-1-runyu.xiao@seu.edu.cn/
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20260902041915.3453421-1-runyu.xiao@seu.edu.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Kumar Kartikeya Dwivedi says:
====================
Misc bug fixes - part 3
A set of miscellaneous fixes for bugs reported by Nicholas, batched
together again. See commit logs for details. Some of this was caught and
posted by Ning before, but AI raised some concerns, so I'm resolving
those issues and commandeering their patches now.
Changelog:
----------
v1 -> v2
v1: https://lore.kernel.org/bpf/20260904063650.3877826-1-memxor@gmail.com
* Fix GCC-BPF failure due to missed BTF emission for a type.
====================
Link: https://patch.msgid.link/20260904084325.52250-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Add a sleepable verifier test that loads a refcount-only local kptr in an
explicit RCU read-side critical section, ends the section, and passes the
pointer to bpf_refcount_acquire().
The loaded pointer never carries NON_OWN_REF. After RCU unlock it retains
MEM_ALLOC while becoming PTR_UNTRUSTED, which previously made the kfunc
argument check accept it as a live allocated object. Expect verification to
reject the untrusted argument instead.
Signed-off-by: Ning Ding <dingning04@gmail.com>
[ kkd: Rewrote commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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When the final RCU read-side critical section ends, a local kptr is demoted
to PTR_UNTRUSTED but retains MEM_ALLOC. The pointer may be NULL or may refer
to an object whose lifetime is no longer protected.
type_is_ptr_alloc_obj() nevertheless recognizes any PTR_TO_BTF_ID with
MEM_ALLOC as a live allocated object. In particular, a refcount-only local
kptr never carries NON_OWN_REF, so it still passes the
bpf_refcount_acquire() argument check after RCU protection ends. The kfunc
can then dereference NULL or stale memory.
Make type_is_ptr_alloc_obj() reject PTR_UNTRUSTED pointers. Since
type_is_non_owning_ref() is based on the same predicate, graph kfunc
arguments obey the same live-object requirement. Fault-protected reads of
the demoted pointer remain valid: writes are already rejected, and read
fixups use bpf_may_fault_on_deref() rather than this predicate.
Fixes: 1b12171533a9 ("bpf: Mark direct ld of stashed bpf_{rb,list}_node as non-owning ref")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Ning Ding <dingning04@gmail.com>
[ kkd: Rewrote commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.
Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.
Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.
Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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A local kptr load of an object containing a graph node is marked MEM_RCU
and NON_OWN_REF while protected by RCU. When the last RCU read-side critical
section ends, invalidate_rcu_protected_refs() removes MEM_RCU and marks the
pointer PTR_UNTRUSTED, but leaves NON_OWN_REF set.
The stale flag lets graph kfunc argument checks continue treating the
pointer as a live borrowed reference. In particular, bpf_rbtree_remove()
can accept a pointer after its protection ended and return it as a new
owning reference, even though the object may already have been freed.
Clear NON_OWN_REF when an RCU-protected pointer is demoted. A spin lock also
provides implicit RCU protection, so invalidate non-owning references before
demoting RCU-protected pointers when releasing the lock. Otherwise the
demotion would clear the flag before invalidate_non_owning_refs() can find
and invalidate those aliases.
The demoted pointer remains available for fault-protected reads. Exempt such
reads from the allocated-object reference-state assertion; writes through a
fault-prone pointer are already rejected, and bpf_may_fault_on_deref() makes
the surviving loads use BPF_PROBE_MEM.
Fixes: 1b12171533a9 ("bpf: Mark direct ld of stashed bpf_{rb,list}_node as non-owning ref")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Add verifier coverage for the distinction between owning and borrowed
arguments to bpf_refcount_acquire().
An owning pointer returned by bpf_obj_new() must continue producing a
non-NULL result without an extra check. An RCU-loaded local kptr is only
borrowed, so a checked result must load successfully while passing an
unchecked result to bpf_obj_drop() must be rejected as possibly NULL.
Use a sleepable syscall program for the borrowed cases so the explicit RCU
critical section is what permits the local kptr load. Without the verifier
fix, the unchecked case is incorrectly accepted. With it, the verifier
rejects the possibly NULL argument.
Signed-off-by: Ning Ding <dingning04@gmail.com>
[ kkd: Rewrote commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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bpf_refcount_acquire() is fallible for a borrowed reference because the
object may have reached a zero refcount. The verifier therefore keeps
KF_RET_NULL on the return value unless the argument is an owning reference.
An RCU-protected load of a local kptr is marked MEM_ALLOC, but it only
receives NON_OWN_REF when the pointee contains a graph node. A refcounted
object without a graph node consequently looks like an owning reference
even though the loaded register has no acquired reference state. If the
program drops the last real reference while remaining in the RCU critical
section, refcount_inc_not_zero() returns NULL while the verifier treats the
result as non-NULL.
Only classify the argument as owning when it is backed by a verifier-tracked
reference. This retains the non-NULL return for pointers from bpf_obj_new(),
bpf_kptr_xchg(), or an earlier successful acquisition, while requiring a
NULL check for borrowed RCU kptrs.
Fixes: 1b12171533a9 ("bpf: Mark direct ld of stashed bpf_{rb,list}_node as non-owning ref")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Ning Ding <dingning04@gmail.com>
[ kkd: Rewrote commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Add verifier coverage for the two ways a non-percpu pointer can be stored
in a __percpu_kptr field: a program-BTF local allocation returned by
bpf_obj_new(), and a referenced kernel-BTF task_struct pointer.
Without the verifier fix, both programs are unexpectedly accepted and the
negative tests fail. Requiring MEM_PERCPU makes both programs fail
verification with the expected invalid-kptr diagnostic.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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map_kptr_match_type() treats perm_flags as the set of register type flags
that a kptr field permits. Adding MEM_PERCPU to that set for
BPF_KPTR_PERCPU does not require the source register to carry it, however.
The subset test consequently accepts both a plain bpf_obj_new() allocation
and a referenced kernel pointer into a __percpu_kptr map field.
Loads from the field are always marked MEM_PERCPU. Consumers then treat the
stored value as the cookie returned by bpf_percpu_obj_new(): per-CPU pointer
helpers relocate it, and map teardown selects the per-CPU free path. A plain
allocation can therefore provide an arbitrary kernel read/write, while a
kernel pointer can be relocated into an invalid address or sent through a
missing destructor.
Require the source MEM_PERCPU flag to match the destination field kind.
This preserves valid bpf_percpu_obj_new() stores and rejects both the
program-BTF and kernel-BTF variants.
Fixes: 36d8bdf75a93 ("bpf: Add alloc/xchg/direct_access support for local percpu kptr")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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HWSPNLCK_TIMEOUT is passed to hwspin_lock_timeout_in_atomic(), whose
timeout argument is in milliseconds, not microseconds:
atomic_delay += HWSPINLOCK_RETRY_DELAY_US;
if (atomic_delay > to * 1000)
return -ETIMEDOUT;
So stm32mp_exti_set_type() asks for a 1 second timeout where the comment
next to the macro says it wants 1 millisecond. The semaphore is polled
with udelay() from a section that holds chip_data->rlock, a
raw_spinlock_t, so preemption stays disabled for the whole wait on every
configuration, PREEMPT_RT included.
The hwspinlock core documents this explicitly:
If the mode is HWLOCK_IN_ATOMIC (called from an atomic context) the
timeout is handled with busy-waiting delays, hence shall not exceed
few msecs.
Fixes: 5257169ade8c ("irqchip/stm32-exti: Use the hwspin_lock_timeout_in_atomic() API")
Signed-off-by: Ju Nan <junan76@163.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Radu Rendec <radu@rendec.net>
Reviewed-by: Antonio Borneo <antonio.borneo@foss.st.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260821024756.24927-2-junan76@163.com
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This reverts commit 6be6cba9c4371d27f78d900ccfe34bb880d9ee20.
Commit 6be6cba9c437 ("irqchip/mbigen: Fix mbigen node address layout")
appears to cause a regression on Hi1616.
On-board hns NIC has two ports, enahisic2i0 and enahisic2i1, both
behind mbigen-v2. Port 0 works; port 1 cannot pass any traffic.
Their interrupt pins fall on different mbigen nodes:
enahisic2i0: pins 1152-1198 -> all in node 9
enahisic2i1: pins 1200-1246 -> node 9 (1200-1215) + node 10 (1216-1246)
(nid = (hwirq - 64) / 128 + 1; pin 1215 = node 9, pin 1216 = node 10)
/proc/interrupts shows the break happens exactly at the node boundary:
enahisic2i1-rx0 pin 1200 count 102 <- node 9
enahisic2i1-rx5 pin 1215 count 1 <- node 9, last pin
enahisic2i1-tx5 pin 1216 count 0 <- node 10, first pin
enahisic2i1-rx6 pin 1218 count 0 <- node 10
...all node 10 pins stay at zero.
Port 0 (entirely node 9) is unaffected. Reverting the commit restores
normal operation.
The commit assumes CLEAR occupies a full 4 KB page at [0xa000, 0xb000)
and collides with node 10, so node 10+ gets shifted by 0x1000.
But get_mbigen_clear_reg() uses flat, chip-wide addressing -- it never
multiplies by the node ID:
*addr = (hwirq / 32) * 4 + REG_MBIGEN_CLEAR_OFFSET; /* 0xa000 */
Over the valid hwirq range [64, 1407], CLEAR only spans 0xa008-0xa0af
(168 bytes). Node 10's registers are:
TYPE: 0xa000-0xa00f (16 B) overlaps CLEAR by 8 B (0xa008-0xa00f)
VEC: 0xa200-0xa3ff (512 B) no overlap with CLEAR
Shifting the whole page moves VEC from 0xa200 to 0xb200. The hardware
reads the event ID from the fixed silicon address 0xa200 on interrupt
firing, but software wrote it to 0xb200 -- so the hardware gets an
uninitialised value and the interrupt is lost.
The only real overlap is 8 bytes of TYPE. It can only trigger when a
single mbigen instance has devices on both node 1 (CLEAR 0xa008) and
node 10 (TYPE 0xa008). On Hi1616 those nodes are on separate mbigen
instances, so it never triggers.
Fixes: 6be6cba9c4371d27f78d900ccfe34bb880d9ee20 ("irqchip/mbigen: Fix mbigen node address layout")
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: caina <caina@uniontech.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Yipeng Zou <zouyipeng@huawei.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260821091720.16665-1-caina@uniontech.com
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Switch the sysfs code to use scnprintf() to avoid warnings about potential
truncation of the names of the sysfs attributes. We can't increase the buffer
size because the size is the part of an ABI for some reason. Note, with
the current size of buffer the affected attributes have a room for up to
1000 names, which ought to be enough for all cases. There is no functional
change, as the same limitation was implied before.
Fixes: c56f5c0342df ("Thermal: Make Thermal trip points writeable")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20260817103324.1020212-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Add missing CLANG_TARGET_FLAGS_loongarch and RUST_TARGET_FLAGS_loongarch
so that perf can be built with clang and enable rust cross compilation.
Cc: stable@vger.kernel.org
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Dmitrii Dolgov <9erthalion6@gmail.com>
Signed-off-by: Haiyong Sun <sunhaiyong@loongson.cn>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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In kvm_loongarch_cpucfg_set_attr() the check-then-set on
kvm->arch.pv_features is lockless, so two vCPUs can race past the
validation and set different values. Add a spinlock to protect it.
Cc: stable@vger.kernel.org
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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pch_msi_set_irq() passes e->msi.data straight into eiointc_set_irq() as
the irq number. The MSI data comes from userspace, that either via a
KVM_IRQ_ROUTING_MSI entry set with KVM_SET_GSI_ROUTING (used by irqfd
and KVM_IRQ_LINE) or directly via KVM_SIGNAL_MSI, and is never checked
against EIOINTC_IRQS.
eiointc_set_irq() uses the value with __set_bit()/__clear_bit() on the
256-bit isr bitmap, eiointc_update_irq() then indexes sw_coremap[] and
the per-cpu coreisr/sw_coreisr bitmaps with it. Therefore a data value
>= 256 reads and writes memory past the end of those arrays, i.e. any
process holding a VM fd can corrupt kernel memory beyond the allocation
of loongarch_eiointc.
Reject MSI data that doesn't fit in the EIOINTC irq space. The DMSINTC
path is unaffected as it decodes the vector from the address and masks
it.
Cc: stable@vger.kernel.org
Fixes: 1928254c5ccb ("LoongArch: KVM: Add irqfd support")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260531140921.1B1181F00893@smtp.kernel.org/
Reviewed-by: Tao Cui <cuitao@kylinos.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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kvm_arch_prepare_memory_region() computes new->arch.flags, i.e. whether
a memslot is KVM_MEM_HUGEPAGE_CAPABLE or KVM_MEM_HUGEPAGE_INCAPABLE,
only for KVM_MR_CREATE and KVM_MR_MOVE, and returns early for every
other change. But the generic code allocates a zeroed memslot for every
change and never copies old->arch, so after a KVM_MR_FLAGS_ONLY update,
e.g. toggling KVM_MEM_LOG_DIRTY_PAGES for live migration, the active
memslot has arch.flags == 0.
With both flags clear, fault_supports_huge_mapping() falls through to
the alignment check on the HVA range alone, which no longer verifies
that the GPA and HVA have the same offset within a PMD. A memslot that
was marked KVM_MEM_HUGEPAGE_INCAPABLE because of a GPA/HVA offset
mismatch can then be mapped with PMD entries on read faults, and since
kvm_map_page() aligns the gfn and the pfn independently, the guest ends
up accessing the wrong host pages, exactly the "d -> f, e -> g" case
described in the comment above the check.
Carry the arch flags over from the old memslot for KVM_MR_FLAGS_ONLY,
as the GPA, HVA and size are guaranteed to be unchanged for that case.
Cc: stable@vger.kernel.org
Fixes: 7ab6fb505b2a ("LoongArch: KVM: Optimization for memslot hugepage checking")
Tested-by: Tao Cui <cuitao@kylinos.cn>
Reviewed-by: Tao Cui <cuitao@kylinos.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Function kvm_arch_flush_remote_tlbs_memslot() is not called any more, so
remove this API.
Reviewed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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kvm_loongarch_env_init() allocates the per-CPU kvm_context (vmcs) and
kvm_loongarch_ops, registers the perf callbacks, and then registers
the IPI/EIOINTC/PCH-PIC/DMSINTC KVM devices. If any of those device
registrations fails, the function returned the error directly, leaving
everything acquired so far in place: vmcs and kvm_loongarch_ops are
never freed, the perf callbacks stay registered, and all previously
registered KVM device operations remain registered. kvm_loongarch_init()
propagates the errors without calling kvm_loongarch_env_exit(), so
nothing else cleans up either.
Unwind the error path in reverse order of registration, so that each
failure only undoes what had actually been set up. Use the same helpers
in kvm_loongarch_env_exit() to remove the device registrations during
normal teardown as well.
Cc: stable@vger.kernel.org
Fixes: c532de5a67a7 ("LoongArch: KVM: Add IPI device support")
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Chaithanya Lagisetty <nagachaithanya9911@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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|
The IPI/EIOINTC/PCH-PIC/DMSINTC KVM devices each have a helper that
registers their kvm_device_ops, but there is no counterpart to remove
them, so a caller that needs to undo a registration has to open-code
kvm_unregister_device_ops() with the matching device type.
Add kvm_loongarch_unregister_{ipi,eiointc,pch_pic,dmsintc}_device()
next to the existing register helpers. kvm_unregister_device_ops() is a
no-op when the corresponding device type is not currently registered.
No functional change, as there are no callers yet.
Cc: stable@vger.kernel.org
Suggested-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Chaithanya Lagisetty <nagachaithanya9911@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
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kvm_loongarch_init() calls kvm_loongarch_env_init() to allocate the
per-CPU kvm_context (vmcs) and kvm_loongarch_ops and to register the
perf callbacks, and then calls kvm_init(). If kvm_init() fails its
result is returned directly, but since module_init() does not run the
module_exit() stuff on failure, so kvm_loongarch_env_exit() is never
called and those resources are leaked.
So call kvm_loongarch_env_exit() when kvm_init() fails, matching the
teardown-on-failure pattern used by riscv_kvm_init().
Cc: stable@vger.kernel.org
Fixes: 2bd6ac687261 ("LoongArch: KVM: Implement kvm module related interface")
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Chaithanya Lagisetty <nagachaithanya9911@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
In the LoongArch BPF JIT code, the branch offset represents the number
of instructions. An offset of 1 means the target of the "beq" is the
current PC plus 1 instruction (PC + 4 bytes). This matches the exact
same path as the sequential non-branch execution, the "or" instruction
is always executed for the cast_user JIT arm in build_insn().
If the pointer is not NULL, there is no side effect. But if the pointer
is NULL, it is incorrectly combined with the base address and turns into
a non-zero address, meaning a zero arena offset no longer casts to NULL.
Fix this by changing the branch offset from 1 to 2, which properly skips
the "or" instruction and jumps directly to the "move_reg" instruction if
the pointer is NULL, ensuring the destination register is safely cleared
to 0.
Cc: stable@vger.kernel.org
Fixes: 4fdb5dd8aeba ("LoongArch: BPF: Implement bpf_addr_space_cast instruction")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
LoongArch uses break 11 for the breakpoint placed after an instruction
that Kprobes executes out of line. Since userspace can issue the same
break instruction, do_bp() can reach kprobe_singlestep_handler() when
there is no current probe.
The handler actually returns false in this case, but it first calls
preempt_enable_no_resched(). The corresponding preempt_disable() is done
by kprobe_breakpoint_handler() on a real Kprobe hit, so it has not run
here. As a result, an ordinary userspace breakpoint (code 11) underflows
the current task's preempt count.
This also makes in_interrupt() return true until the task schedules. One
visible consequence is the socket cgroup attribution: cgroup_sk_alloc()
treats the allocation as interrupt context and assigns the socket to the
root cgroup. A socket opened from the SIGTRAP handler can then avoid a
BPF_CGROUP_INET_SOCK_CREATE policy attached to the task's own cgroup.
Return as soon as kprobe_running() reports no active probe.
The same check has appeared in [PATCH v10 2/4] of the original LoongArch
Kprobes series, but was dropped before the feature reached mainline.
Cc: stable@vger.kernel.org
Fixes: 6d4cc40fb5f5 ("LoongArch: Add kprobes support")
Link: https://lore.kernel.org/loongarch/1670575981-14389-3-git-send-email-yangtiezhu@loongson.cn/
Assisted-by: Codex:gpt-5
Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
The rethook trampoline saves $r21 ($u0), the percpu base, into its frame
at entry and restores it at exit. Inbetween rethook_trampoline_handler()
may schedule via preempt_enable_notrace().
If the task migrates to another CPU, the frame's $r21 holds the old
CPU's percpu base, and restoring it poisons $r21 on the new CPU. Until
the next user->kernel transition heals $r21, all this_cpu_*() accesses
(runqueues, RCU per-CPU data, timer tick programming, FPU ownership)
hit the wrong CPU's percpu area.
Under kretprobe-heavy preemptible load this can corrupt scheduler and
timer state: scheduling-while-atomic splats, wrong-CPU RCU warnings,
WARN_ON_ONCE(rq != this_rq()) in nohz_balance_exit_idle(), and CPUs
parking in the idle loop with the constant timer never re-armed (hard
lockup). Reproduces on a Loongson-3A6000 with kretprobes on VFS paths
plus heavy file churn (OS install / unsquashfs).
By convention $r21 always holds the current CPU's percpu base in kernel
mode: SAVE_SOME() at exception entry reloads it only when coming from
user mode, and RESTORE_SOME() restores it only when returning to user
mode; the context-switch path never writes it. Therefore the live $r21
at trampoline exit is already correct, and nothing inbetween can change
it legitimately (kernel C code cannot write a global register variable).
The same flaw existed even in the pre-rethook kretprobe trampoline since
v6.3; it was carried over when rethook replaced it. Drop both the save
and the restore here. Drop the restore is enough to solve the issue, and
drop the save is to keep the code tidy and no need to clear it.
Cc: stable@vger.kernel.org # v6.3+
Fixes: 3f5536860086d ("LoongArch: Add kretprobes support")
Assisted-by: Kimi:Kimi-K3 # debug and root-cause analysis
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
setup_profiling_timer() is not used by any code at this point. Since a
default weak implementation exists, there is no need to still keep this
arch-specific definition around. Remove it along with the now-redundant
profile header includes.
Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
Correct "avaliable" to "available", reported by scripts/checkpatch.pl
using the misspelling list in scripts/spelling.txt. It only touches the
comments, no code changes.
Assisted-by: Cursor:claude-opus-5
Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
After commit 2625480a1bf7 ("hardening: Default randstruct off with rust
for better allmodconfig support"), which allows Rust to be enabled for
allmodconfig, ARCH=loongarch allmodconfig starts failing with:
error: kernel-address sanitizer is not supported for this target
error: aborting due to 1 previous error
make[4]: *** [rust/Makefile:741: rust/core.o] Error 1
For the same reason as the commit 84a0f7caafc679f7 ("ARM: Do not select
HAVE_RUST when KASAN is enabled"), do not select HAVE_RUST when KASAN
is enabled until the loongarch64-unknown-none-softfloat target in rustc
supports KASAN.
Cc: stable@vger.kernel.org
Fixes: 90868ff9cade ("LoongArch: Enable initial Rust support")
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
Correct "upto" to "up to", reported by scripts/checkpatch.pl using the
misspelling list in scripts/spelling.txt. Only touches comments, no code
changes.
Assisted-by: Cursor:claude-opus-5
Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com>
Link: https://patch.msgid.link/20260904103732.7320-1-hemanth.selam@gmail.com
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
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Check that a register-form NULL check does not lift PTR_MAYBE_NULL on
a path where the compared register is non-zero. W/o the previous patch
the program is accepted.
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-8-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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check_cond_jmp_op() accepts "if rA <op> rB" as a NULL check for a
nullable pointer rA when rB is a scalar known to be zero,
lifts PTR_MAYBE_NULL from rA in the corresponding branch and does not
mark rB precise. Consider the following program:
r0 = bpf_get_prandom_u32();
r6 = 1; /* the r6 == 0 path is explored first */
if (r0 == 0) goto 1f;
r6 = 0;
1:
r0 = bpf_map_lookup_elem(map, &0); /* absent, NULL at runtime */
if (r0 == r6) goto 2f; /* taken as a NULL check for r0 */
*(u8 *)(r0 + 0); /* verifier: map value; runtime: zero */
2:
return 0;
The r6 == 0 path is explored first and the dereference is accepted.
The r6 == 1 path is pruned at the checkpoint recorded for (1),
so the comparison is never verified with a non-zero r6. At runtime a
failed lookup returns NULL, NULL != 1 takes the non-NULL edge and the
program dereferences a pointer that is zero.
Fixes: 2f4cb53eed44 ("bpf: detect non null pointer with register operand in JEQ/JNE.")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-7-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which
the verifier used to skip, contains an out of bounds map value access,
hence w/o the previous patch the program is accepted. See previous patch
for detailed description.
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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Consider the following program:
r1 = map_value; /* low 32 bits are zero at runtime */
r6 = 0xdead000000000000;
if w1 != 0 goto l1;
l0: r1 += r6;
r2 = *(u64 *)(r1 + 0);
exit;
l1: r6 = 0;
goto l0;
At the moment is_branch_taken() reports the jump as always taken,
because it does not distinguish between BPF_JMP and BPF_JMP32
comparisons when processing 'if w1 != 0 ...'.
Fixes: cac616db39c2 ("bpf: Verifier track null pointer branch_taken with JNE and JEQ")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-5-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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|
linked_regs_too_many_regs checks that collect_linked_regs() ties at most
LINKED_REGS_MAX registers for a single jump. Compare r5 instead of r0,
so that the register the jump compares is itself the member that does
not fit, and check that it comes out of the jump unlinked.
W/o the previous patch env->{false,true}_reg{1,2} bring r5's id back and
insn 7 is logged as "R5=scalar(id=1,...)".
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-4-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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check_cond_jmp_op() copies the compared registers into
env->{false,true}_reg{1,2} before collect_linked_regs() runs and copies
those snapshots back into both branch states afterwards.
collect_linked_regs() records at most LINKED_REGS_MAX members of a
linked registers group in the jump history and calls clear_scalar_id()
for every member that does not fit. The compared register is not exempt
from that.
As a consequence, sync_linked_regs() might adjust ranges for more
registers than bpf_bt_sync_linked_regs() can propagate precision to.
Collect the linked registers before the snapshots are taken instead.
This might lead to some unnecessary clear_scalar_id's, but from
previous testing situations with many linked registers are
extremely rare.
Fixes: ec1d77cb0ee9 ("bpf: Use bpf_verifier_env buffers for reg_set_min_max")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-3-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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|
Check that a comparison against a pointer whose offset is not bounded
from above does not make the verifier infer that a nullable pointer is
not NULL, and that a bounded offset still does. W/o the previous patch
the first test is accepted.
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-2-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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reg_not_null() decides that a register holds a non-NULL value by
looking at its type alone. For pointer types that allow arithmetic the
type only guarantees a non-NULL base, in case of an unbound offset
the runtime offset value might still add up to NULL.
Consider the followng program:
r6 = bpf_map_lookup_elem(map, &0); /* present */
if (r6 == 0) return 0;
r7 = bpf_map_lookup_elem(map, &1); /* absent, NULL at runtime */
r8 = r7;
r8 -= r6; /* pointer - pointer: unknown scalar, -r6 */
r8 <<= 1;
r8 >>= 1; /* any non-negative offset is accepted by */
/* check_reg_sane_offset_ptr() */
r6 += r8; /* verifier: map value; runtime: zero */
if (r7 != r6) return 0;
*(u8 *)(r7 + 0); /* r7 is inferred non-NULL, both are zero */
At runtime both registers are zero, the comparison is true and the
load faults with NULL pointer dereference.
Require the offset to be within +-BPF_MAX_VAR_OFF in reg_not_null().
Fixes: cac616db39c2 ("bpf: Verifier track null pointer branch_taken with JNE and JEQ")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-1-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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A small fix on the error handling of an OA uapi and the
addition of a drm_info message to report FLAT_CSS base misalignment.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patch.msgid.link/apnVOtDv4WAIoj_X@intel.com
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amd-drm-fixes-7.3-2026-09-03:
amdgpu:
- SR-IOV fix
- GFX8 fix
- MES queue reset fix
- GPUVM fixes
- DCN 6 warning fix
- DCN 3.5/3.6 fix
- DML fix
- Backlight fix
- Colorop fix
- DC get_estimated_bw() fix
- devcoredump fix
- Userq fixes
- APU PSP fix
- Cursor fix
amdkfd:
- MES queue eviction fix
- MQD debugfs fix
UAPI:
- Fix for drm_amdgpu_info_device with mixed 64 bit kernel and 32 bit userspace
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20260903174712.584320-1-alexander.deucher@amd.com
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ieee80211_set_bitrate_mask() checks if the interface is running via
ieee80211_sdata_running(), but it does not check if the interface is
still present in the driver.
When sdata is running but IEEE80211_SDATA_IN_DRIVER is not set, the
call reaches drv_set_bitrate_mask() in driver-ops.h which hits
wlan1: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.h:884 at drv_set_bitrate_mask
Syzkaller triggers this via wext SIOCSIWRATE ioctl. The Call Trace shows
wext_ioctl_dispatch() in wext-core.c dispatching the ioctl, calling
ioctl_standard_call() for SIOCSIWRATE, which calls cfg80211_wext_siwrate()
in wext-compat.c. That builds a bitrate mask and calls
rdev_set_bitrate_mask() which ends up in ieee80211_set_bitrate_mask() in
cfg.c. The interface is marked running via SDATA_STATE_RUNNING but
flags is 0, so check_sdata_in_driver() fails.
When the interface is being torn down, or when wext ioctl is issued
during interface bringup before drv_add_interface() sets IN_DRIVER, the
running check passes while IN_DRIVER is clear.
Check IEEE80211_SDATA_IN_DRIVER in ieee80211_set_bitrate_mask() before
calling the driver, returning -ENETDOWN. This avoids the WARN_ONCE in
driver-ops.h and matches other cfg.c operations that bail early when not
in driver.
This change should be safe because wiphy mutex is held in
cfg80211_wext_siwrate() via guard(wiphy), and IN_DRIVER is set/cleared
under RTNL and wiphy paths in drv_add_interface() and
drv_remove_interface() in driver-ops.c, so the check is race-free
against driver add/remove. Returning -ENETDOWN is the same error other
not-running paths use and does not introduce new locking.
Reported-by: syzbot+af177aa139efdd13a9da@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=af177aa139efdd13a9da
Link: https://lore.kernel.org/all/6a75205c.59b6c763.2bba34.00c3.GAE@google.com/
Fixes: 554a43d5e77e ("mac80211: check sdata_running on ieee80211_set_bitrate_mask")
Cc: stable@vger.kernel.org
Assisted-by: Hermes:muse-spark-1.2 syzkaller
Signed-off-by: Rik van Riel <riel@surriel.com>
Link: https://patch.msgid.link/20260808104755.319c686e@fangorn
Reported-by: syzbot+dcaca020ca8377e7ced0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=dcaca020ca8377e7ced0
[also add second syzbot report]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Commit ba7425312607 ("mm, slab: add an optimistic
__slab_try_return_freelist()") incorrectly assumed that nobody has freed
an object to the slab as long as slab->freelist is NULL and cmpxchg
succeeds.
However, as reported by Hyunwoo Kim [1], other CPUs might have freed
an object to the slab, insert the slab to the partial list, then
allocated an object from the slab, and be in the middle of removing
the slab from the list under n->list_lock.
Since __refill_objects_node() puts the slab back on pc.slabs
outside n->list_lock, it might insert the slab into that list while
the slab is concurrently being removed from n->partial.
This led to a list corruption [1]:
list_add corruption. next->prev should be prev
(ffff888100000248), but was dead000000000122.
(next=ffffea000416e410).
kernel BUG at lib/list_debug.c:29!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 1 UID: 65534 PID: 144 Comm: poc Not tainted
7.2.0-16172-gcf72cbb39da8-dirty #1 PREEMPT(lazy)
RIP: 0010:__list_add_valid_or_report+0x80/0xd0
...
Call Trace:
alloc_from_new_slab+0x183/0x300
___slab_alloc+0x31c/0x890
__kmalloc_noprof+0x3d4/0x800
lsm_blob_alloc+0x2d/0x50
security_msg_msg_alloc+0x26/0x90
load_msg+0x1aa/0x210
do_msgsnd+0x91/0x800
do_syscall_64+0x109/0x5d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
Kernel panic - not syncing: Fatal exception
This is a classic ABA problem where cmpxchg succeeds but the state has
changed since __refill_objects_node() took the freelist from the slab.
As Vlastimil Babka mentioned [2], it should be rare to return more than
one slab (due to the racy read of slab->counters in
get_partial_node_bulk()). Therefore, instead of introducing additional
complexity, acquire and release n->list_lock twice in the worst case.
Return the slab directly to the partial list and hold n->list_lock
across the cmpxchg and add_partial(). This is similar to the initial
version of commit ba7425312607 [3]. This is enough to avoid the race as
the list manipulation is serialized by n->list_lock. While at it,
bring back unlikely() hint now that the condition is unlikely.
Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Closes: https://lore.kernel.org/linux-mm/apPa-cGLcyt90l-E@v4bel [1]
Link: https://lore.kernel.org/linux-mm/ae25c193-b95f-40c1-83b6-1c2546467e41@kernel.org [2]
Link: https://lore.kernel.org/all/20260421-b4-refill-optimistic-return-v1-1-24f0bfc1acff@kernel.org [3]
Fixes: ba7425312607 ("mm, slab: add an optimistic __slab_try_return_freelist()")
Cc: stable@vger.kernel.org
Signed-off-by: Harry Yoo (Meta) <harry@kernel.org>
Link: https://patch.msgid.link/20260903-slab-fix-aba-v3-1-b44cb6badd54@kernel.org
Reviewed-by: Hao Li <hao.li@linux.dev>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
|
|
This partially reverts commit 2a8bb29ec9b2 ("mm/slab: allow
kfree_rcu_sheaf() on PREEMPT_RT"). It was based on the assumption that
local_trylock() is safe on PREEMPT_RT from any context.
However kvfree_rcu() is also called by set_cpus_allowed_force() with
task_struct::pi_lock acquired and there it's not safe, as syzbot
has reported.
For the immediate fix, skip kfree_rcu_sheaf() on PREEMPT_RT again from
kvfree_call_rcu(). In theory, kfree_rcu_nolock() would have the same
problem when called from under pi_lock on PREEMPT_RT but that can
be addressed if such a caller is proposed.
Add an explanation comment, courtesy of Sebastian.
Reported-by: syzbot+acf142088e0182172e58@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=acf142088e0182172e58
Reported-by: ThangNN99 <ngocthang2710.1999@gmail.com>
Fixes: 2a8bb29ec9b2 ("mm/slab: allow kfree_rcu_sheaf() on PREEMPT_RT")
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260831-b4-kfree_rcu_hotfix-v1-1-4f0fb882638b@kernel.org
Reviewed-by: Harry Yoo (Meta) <harry@kernel.org>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
|
|
Commit 0a36bad01731 ("release_task: kill the no longer needed
get/put_pid(thread_pid)") removed the reference around proc_flush_pid().
It assumed that free_pids(post.pids) at the end of release_task() would
keep thread_pid alive until then.
That assumption is wrong. __change_pid() only records a detached PID in
post.pids when pid_has_task() is false for every PIDTYPE. If another task
still uses the exiting task's PID as its process group or session ID,
__unhash_process() removes the exiting task's PIDTYPE_PID link but leaves
the PID out of post.pids. release_task() therefore holds no reference to
it after dropping tasklist_lock.
The other task can then remove the remaining PIDTYPE links. Its
free_pids() call schedules delayed_put_pid(), and the RCU callback can free
the PID before the first release_task() reaches proc_flush_pid().
An unprivileged reproducer races wait4(-1) against setsid() to trigger this
ordering. Three of three fresh v7.2 KASAN boots reported:
BUG: KASAN: slab-use-after-free in
proc_invalidate_siblings_dcache+0x3e2/0x3f0
Read of size 8 by task h7_pid_reaper/1921
Call Trace:
proc_invalidate_siblings_dcache
release_task
wait_consider_task
__do_wait
do_wait
kernel_wait4
Freed by task 0:
kmem_cache_free
put_pid
delayed_put_pid
rcu_core
Last potentially related work creation:
__call_rcu_common
free_pids
ksys_setsid
KASAN identified a 144-byte object from the pid cache and located the bad
read 80 bytes into the freed object, matching pid->inodes. With an
explicit reference, three of three fresh boots completed without a KASAN
report. The concurrent RCU callback dropped its reference while
proc_flush_pid() was protected, and the balancing put_pid() performed the
final free afterward.
Take a reference before __unhash_process() clears p->thread_pid and release
it after proc_flush_pid() completes.
A tested source reproducer is available privately on request. No
controlled read or write, information leak, or privilege escalation is
claimed. The mainline patch applies directly to v6.19.y and newer;
v6.16.y through v6.18.y need a context-adjusted backport.
Fixes: 0a36bad01731 ("release_task: kill the no longer needed get/put_pid(thread_pid)")
Reported-by: syzbot+0aee5e8066eddbbe7397@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0aee5e8066eddbbe7397
Reported-by: syzbot+e8b3520b53e78e90034e@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=e8b3520b53e78e90034e
Cc: stable@vger.kernel.org # see patch description, needs adjustments for 6.16.y-6.18.y
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Link: https://patch.msgid.link/20260831001221.3755948-1-4ncienth@gmail.com
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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DDR50 mode is not required to support the tuning command CMD19, meaning
that calibration may fail on cards that do not implement it, in which
case a known-good itap delay value should be programmed into the host
controller.
Do this by reading the (already defined) itap delay DT property for DDR50
and, if tuning fails for this mode, fall back to the DT-provided itap delay
value. If the DT does not provide a value for DDR50 fallback then this
simply disables using itapdly.
Fixes: 901d16e46296 ("mmc: sdhci_am654: Add retry tuning")
Cc: stable@vger.kernel.org
Signed-off-by: Diogo Ivo (Schneider Electric) <diogo.ivo@bootlin.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Judith Mendez <jm@ti.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
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When tuning fails, stale ITAPDLY values can persist and interfere with
subsequent I/O accesses, for example in DDR50 mode in cards with no tuning
support. Move the ITAPDLY enable setting out of the tuning loop to after
successful tuning, and explicitly clear ITAPDLY (delay and enable) when
tuning fails so that we are sure only working values are actually left in
hardware.
Fixes: 901d16e46296 ("mmc: sdhci_am654: Add retry tuning")
Cc: stable@vger.kernel.org
Signed-off-by: Diogo Ivo (Schneider Electric) <diogo.ivo@bootlin.com>
Reviewed-by: Judith Mendez <jm@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
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