The handling of received data in the smbdirect client code involves using
copy_to_iter() to copy data from the smbd_reponse struct's packet trailer
to a folioq buffer provided by netfslib that encapsulates a chunk of
pagecache.
If, however, CONFIG_HARDENED_USERCOPY=y, this will result in the checks
then performed in copy_to_iter() oopsing with something like the following:
CIFS: Attempting to mount //172.31.9.1/test
CIFS: VFS: RDMA transport established
usercopy: Kernel memory exposure attempt detected from SLUB object 'smbd_response_0000000091e24ea1' (offset 81, size 63)!
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:102!
...
RIP: 0010:usercopy_abort+0x6c/0x80
...
Call Trace:
<TASK>
__check_heap_object+0xe3/0x120
__check_object_size+0x4dc/0x6d0
smbd_recv+0x77f/0xfe0 [cifs]
cifs_readv_from_socket+0x276/0x8f0 [cifs]
cifs_read_from_socket+0xcd/0x120 [cifs]
cifs_demultiplex_thread+0x7e9/0x2d50 [cifs]
kthread+0x396/0x830
ret_from_fork+0x2b8/0x3b0
ret_from_fork_asm+0x1a/0x30
The problem is that the smbd_response slab's packet field isn't marked as
being permitted for usercopy.
Fix this by passing parameters to kmem_slab_create() to indicate that
copy_to_iter() is permitted from the packet region of the smbd_response
slab objects, less the header space.
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Reported-by: Stefan Metzmacher <metze@samba.org>
Link: https://lore.kernel.org/r/acb7f612-df26-4e2a-a35d-7cd040f513e1@samba.org/
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Tested-by: Stefan Metzmacher <metze@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order
and prevent the following deadlock from happening
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3-build2+ #1301 Tainted: G S W
------------------------------------------------------
cifsd/6055 is trying to acquire lock:
ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200
but task is already holding lock:
ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_setup_session+0x81/0x4b0
cifs_get_smb_ses+0x771/0x900
cifs_mount_get_session+0x7e/0x170
cifs_mount+0x92/0x2d0
cifs_smb3_do_mount+0x161/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_match_super+0x101/0x320
sget+0xab/0x270
cifs_smb3_do_mount+0x1e0/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:
check_noncircular+0x95/0xc0
check_prev_add+0x115/0x2f0
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_signal_cifsd_for_reconnect+0x134/0x200
__cifs_reconnect+0x8f/0x500
cifs_handle_standard+0x112/0x280
cifs_demultiplex_thread+0x64d/0xbc0
kthread+0x2f7/0x310
ret_from_fork+0x2a/0x230
ret_from_fork_asm+0x1a/0x30
other info that might help us debug this:
Chain exists of:
&tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ret_buf->chan_lock);
lock(&ret_buf->ses_lock);
lock(&ret_buf->chan_lock);
lock(&tcp_ses->srv_lock);
*** DEADLOCK ***
3 locks held by cifsd/6055:
#0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200
#1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200
#2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
Cc: linux-cifs@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Fixes: d7d7a66aac ("cifs: avoid use of global locks for high contention data")
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently, the MCE subsystem sysfs interface will be removed if the
thresholding sysfs interface fails to be created. A common failure is due to
new MCA bank types that are not recognized and don't have a short name set.
The MCA thresholding feature is optional and should not break the common MCE
sysfs interface. Also, new MCA bank types are occasionally introduced, and
updates will be needed to recognize them. But likewise, this should not break
the common sysfs interface.
Keep the MCE sysfs interface regardless of the status of the thresholding
sysfs interface.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-1-236dd74f645f@amd.com
It turns out that the Windows WMI-ACPI driver always enables/disables
WMI events regardless of whether they are marked as expensive or not.
This finding is further reinforced when reading the documentation of
the WMI_FUNCTION_CONTROL_CALLBACK callback used by Windows drivers
for enabling/disabling WMI devices:
The DpWmiFunctionControl routine enables or disables
notification of events, and enables or disables data
collection for data blocks that the driver registered
as expensive to collect.
Follow this behavior to fix the WMI event used for reporting hotkey
events on the Dell Latitude 5400 and likely many more devices.
Reported-by: Dmytro Bagrii <dimich.dmb@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220246
Tested-by: Dmytro Bagrii <dimich.dmb@gmail.com>
Fixes: 656f0961d1 ("platform/x86: wmi: Rework WCxx/WExx ACPI method handling")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20250619221440.6737-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
During driver probe we might be briefly using CT safe mode, which
is based on a delayed work, but usually we are able to stop this
once we have IRQ fully operational. However, if we abort the probe
quite early then during unwind we might try to destroy the workqueue
while there is still a pending delayed work that attempts to restart
itself which triggers a WARN.
This was recently observed during unsuccessful VF initialization:
[ ] xe 0000:00:02.1: probe with driver xe failed with error -62
[ ] ------------[ cut here ]------------
[ ] workqueue: cannot queue safe_mode_worker_func [xe] on wq xe-g2h-wq
[ ] WARNING: CPU: 9 PID: 0 at kernel/workqueue.c:2257 __queue_work+0x287/0x710
[ ] RIP: 0010:__queue_work+0x287/0x710
[ ] Call Trace:
[ ] delayed_work_timer_fn+0x19/0x30
[ ] call_timer_fn+0xa1/0x2a0
Exit the CT safe mode on unwind to avoid that warning.
Fixes: 09b286950f ("drm/xe/guc: Allow CTB G2H processing without G2H IRQ")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250612220937.857-3-michal.wajdeczko@intel.com
(cherry picked from commit 2ddbb73ec2)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
The variable index is modified and reused as array index when modify
register EIOINTC_ENABLE. There will be array index overflow problem.
Cc: stable@vger.kernel.org
Fixes: 3956a52bc0 ("LoongArch: KVM: Add EIOINTC read and write functions")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
When the 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 LoongArch this exposed several places where __init annotations
were missing but ended up being "accidentally correct". So fix these
cases.
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The EFI memory map at 'boot_memmap' is crucial for kdump to understand
the primary kernel's memory layout. This memory region, typically part
of EFI Boot Services (BS) data, can be overwritten after ExitBootServices
if not explicitly preserved by the kernel.
This commit addresses this by:
1. Calling memblock_reserve() to reserve the entire physical region
occupied by the EFI memory map (header + descriptors). This prevents
the primary kernel from reallocating and corrupting this area.
2. Setting the EFI_PRESERVE_BS_REGIONS flag in efi.flags. This indicates
that efforts have been made to preserve critical BS code/data regions
which can be useful for other kernel subsystems or debugging.
These changes ensure the original EFI memory map data remains intact,
improving kdump reliability and potentially aiding other EFI-related
functionalities that might rely on preserved BS code/data.
Signed-off-by: Ming Wang <wangming01@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
After commit a934a57a42 ("scripts/misc-check: check missing #include
<linux/export.h> when W=1") and 7d95680d64 ("scripts/misc-check:
check unnecessary #include <linux/export.h> when W=1"), we get some build
warnings with W=1:
arch/loongarch/kernel/acpi.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/alternative.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/kfpu.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/traps.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/unwind_guess.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/unwind_orc.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/unwind_prologue.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/lib/crc32-loongarch.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/lib/csum.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
arch/loongarch/kernel/elf.c: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present
arch/loongarch/kernel/paravirt.c: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present
arch/loongarch/pci/pci.c: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present
So fix these build warnings for LoongArch.
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
While the GCC and Clang compilers already define __ASSEMBLER__
automatically when compiling assembler code, __ASSEMBLY__ is a macro
that only gets defined by the Makefiles in the kernel. This is bad
since macros starting with two underscores are names that are reserved
by the C language. It can also be very confusing for the developers
when switching between userspace and kernelspace coding, or when
dealing with uapi headers that rather should use __ASSEMBLER__ instead.
So let's now standardize on the __ASSEMBLER__ macro that is provided
by the compilers.
This is almost a completely mechanical patch (done with a simple
"sed -i" statement), with one comment tweaked manually in the
arch/loongarch/include/asm/cpu.h file (it was missing the trailing
underscores).
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Don't mix the namespace and controller values, and validate the
per-controller limit when probing the controller. This avoid spurious
failures for controllers with namespaces that have different namespaces
with different logical block sizes, or report the per-namespace values
only for some namespaces.
It also fixes a missing queue_limits_cancel_update in an error path by
removing that error path.
Fixes: 8695f060a0 ("nvme: all namespaces in a subsystem must adhere to a common atomic write size")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Move all the code out of nvme_update_disk_info into the helper, and
rename the helper to have a somewhat less clumsy name.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
The remove_work will proceed with permanently disconnecting on the
initial final path failure if the head shows no paths after the delay.
If a new path connects while the remove_work is pending, and if that new
path happens to disconnect before that remove_work executes, the delayed
removal should reset based on the most recent path disconnect time, but
queue_delayed_work() won't do anything if the work is already pending.
Attempt to cancel the delayed work when a new path connects, and use
mod_delayed_work() in case the remove_work remains pending anyway.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Marc reported that enabling protected mode on a device with GICv2
doesn't fail gracefully as one would expect, and leads to a host
kernel crash.
As it turns out, the first half of pKVM init happens before the vgic
probe, and so by the time we find out we have a GICv2 we're already
committed to keeping the pKVM vectors installed at EL2 -- pKVM rejects
stub HVCs for obvious security reasons. However, the error path on KVM
init leads to teardown_hyp_mode() which unconditionally frees hypervisor
allocations (including the EL2 stacks and per-cpu pages) under the
assumption that a previous cpu_hyp_uninit() execution has reset the
vectors back to the stubs, which is false with pKVM.
Interestingly, host stage-2 protection is not enabled yet at this point,
so this use-after-free may go unnoticed for a while. The issue becomes
more obvious after the finalize_pkvm() call.
Fix this by keeping track of the CPUs on which pKVM is initialized in
the kvm_hyp_initialized per-cpu variable, and use it from
teardown_hyp_mode() to skip freeing pages that are in fact used.
Fixes: a770ee80e6 ("KVM: arm64: pkvm: Disable GICv2 support")
Reported-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20250626101014.1519345-1-qperret@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
If an AUX event overruns, the event core layer intends to disable the
event by setting the 'pending_disable' flag. Unfortunately, the event
is not actually disabled afterwards.
In commit:
ca6c21327c ("perf: Fix missing SIGTRAPs")
the 'pending_disable' flag was changed to a boolean. However, the
AUX event code was not updated accordingly. The flag ends up holding a
CPU number. If this number is zero, the flag is taken as false and the
IRQ work is never triggered.
Later, with commit:
2b84def990 ("perf: Split __perf_pending_irq() out of perf_pending_irq()")
a new IRQ work 'pending_disable_irq' was introduced to handle event
disabling. The AUX event path was not updated to kick off the work queue.
To fix this bug, when an AUX ring buffer overrun is detected, call
perf_event_disable_inatomic() to initiate the pending disable flow.
Also update the outdated comment for setting the flag, to reflect the
boolean values (0 or 1).
Fixes: 2b84def990 ("perf: Split __perf_pending_irq() out of perf_pending_irq()")
Fixes: ca6c21327c ("perf: Fix missing SIGTRAPs")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Liang Kan <kan.liang@linux.intel.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-perf-users@vger.kernel.org
Link: https://lore.kernel.org/r/20250625170737.2918295-1-leo.yan@arm.com
host_stage2_adjust_range() tries to find the largest block mapping that
fits within a memory or mmio region (represented by a kvm_mem_range in
this function) during host stage-2 faults under pKVM. To do so, it walks
the host stage-2 page-table, finds the faulting PTE and its level, and
then progressively increments the level until it finds a granule of the
appropriate size. However, the condition in the loop implementing the
above is broken as it checks kvm_level_supports_block_mapping() for the
next level instead of the current, so pKVM may attempt to map a region
larger than can be covered with a single block.
This is not a security problem and is quite rare in practice (the
kvm_mem_range check usually forces host_stage2_adjust_range() to choose a
smaller granule), but this is clearly not the expected behaviour.
Refactor the loop to fix the bug and improve readability.
Fixes: c4f0935e4d ("KVM: arm64: Optimize host memory aborts")
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20250625105548.984572-1-qperret@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
The state of the vcpu's MI line should be asserted when its
ICH_HCR_EL2.En is set and ICH_MISR_EL2 is non-zero. Using bitwise AND
(&=) directly for this calculation will not give us the correct result
when the LSB of the vcpu's ICH_MISR_EL2 isn't set. Correct this by
directly computing the line level with a logical AND operation.
Signed-off-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Link: https://lore.kernel.org/r/20250625084709.3968844-1-r09922117@csie.ntu.edu.tw
[maz: drop the level check from the original code]
Signed-off-by: Marc Zyngier <maz@kernel.org>
ASoC: Fixes for v6.16
A small collection of fixes, the main one being a fix for resume from
hibernation on AMD systems, plus a few new quirk entries for AMD
systems.
Pull bpf fixes from Alexei Starovoitov:
- Fix use-after-free in libbpf when map is resized (Adin Scannell)
- Fix verifier assumptions about 2nd argument of bpf_sysctl_get_name
(Jerome Marchand)
- Fix verifier assumption of nullness of d_inode in dentry (Song Liu)
- Fix global starvation of LRU map (Willem de Bruijn)
- Fix potential NULL dereference in btf_dump__free (Yuan Chen)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: adapt one more case in test_lru_map to the new target_free
libbpf: Fix possible use-after-free for externs
selftests/bpf: Convert test_sysctl to prog_tests
bpf: Specify access type of bpf_sysctl_get_name args
libbpf: Fix null pointer dereference in btf_dump__free on allocation failure
bpf: Adjust free target to avoid global starvation of LRU map
bpf: Mark dentry->d_inode as trusted_or_null
Fix a 6.16 regression from the recovery pass rework, which introduced a
bug where calling bch2_run_explicit_recovery_pass() would only return
the error code to rewind recovery for the first call that scheduled that
recovery pass.
If the error code from the first call was swallowed (because it was
called by an asynchronous codepath), subsequent calls would go "ok, this
pass is already marked as needing to run" and return 0.
Fixing this ensures that check_topology bails out to run btree_node_scan
before doing any repair.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, calling bch2_btree_has_scanned_nodes() when btree node
scan hadn't actually run would erroniously return false - causing us to
think a btree was entirely gone.
This fixes a 6.16 regression from moving the scheduling of btree node
scan out of bch2_btree_lost_data() (fixing the bug where we'd schedule
it persistently in the superblock) and only scheduling it when
check_toploogy() is asking for scanned btree nodes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Pull mount fixes from Al Viro:
"Several mount-related fixes"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
userns and mnt_idmap leak in open_tree_attr(2)
attach_recursive_mnt(): do not lock the covering tree when sliding something under it
replace collect_mounts()/drop_collected_mounts() with a safer variant
The dm_crypt code fails to build without CONFIG_KEYS:
kernel/crash_dump_dm_crypt.c: In function 'restore_dm_crypt_keys_to_thread_keyring':
kernel/crash_dump_dm_crypt.c:105:9: error: unknown type name 'key_ref_t'; did you mean 'key_ref_put'?
There is a mix of 'select KEYS' and 'depends on KEYS' in Kconfig,
so there is no single obvious solution here, but generally using 'depends on'
makes more sense and is less likely to cause dependency loops.
Link: https://lkml.kernel.org/r/20250620112140.3396316-1-arnd@kernel.org
Fixes: 62f17d9df6 ("crash_dump: retrieve dm crypt keys in kdump kernel")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Dave Vasilevsky <dave@vasilevsky.ca>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
memcg_path_store() assigns a newly allocated memory buffer to
filter->memcg_path, without deallocating the previously allocated and
assigned memory buffer. As a result, users can leak kernel memory by
continuously writing a data to memcg_path DAMOS sysfs file. Fix the leak
by deallocating the previously set memory buffer.
Link: https://lkml.kernel.org/r/20250619183608.6647-2-sj@kernel.org
Fixes: 7ee161f18b ("mm/damon/sysfs-schemes: implement filter directory")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org> [6.3.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Howells