Linux: >> Linux Kernel >> 5.15.211 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits
Since commit e424054000878 ("MIPS: Tracing: Reduce the overhead of
dynamic Function Tracer"), the macro UASM_i_LA_mostly has been used,
and this macro can generate more than 2 instructions. At the same
time, the code in ftrace assumes that no more than 2 instructions can
be generated, which is why it stores them in an int[2] array. However,
as previously noted, the macro UASM_i_LA_mostly (and now UASM_i_LA)
causes a buffer overflow when _mcount is beyond 32 bits. This leads to
corruption of the variables located in the __read_mostly section.
This corruption was observed because the variable
__cpu_primary_thread_mask was corrupted, causing a hang very early
during boot.
This fix prevents the corruption by avoiding the generation of
instructions if they could exceed 2 instructions in
length. Fortunately, insn_la_mcount is only used if the instrumented
code is located outside the kernel code section, so dynamic ftrace can
still be used, albeit in a more limited scope. This is still
preferable to corrupting memory and/or crashing the kernel.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix the crash issue for zero copy XDP_TX action
There is a crash issue when running zero copy XDP_TX action, the crash
log is shown below.
[ 216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000
[ 216.187524] Internal error: Oops: 0000000096000144 [#1] SMP
[ 216.301694] Call trace:
[ 216.304130] dcache_clean_poc+0x20/0x38 (P)
[ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0
[ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400
[ 216.317701] __stmmac_xdp_run_prog+0x164/0x368
[ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00
[ 216.326576] __napi_poll+0x40/0x218
[ 216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt
For XDP_TX action, the xdp_buff is converted to xdp_frame by
xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame
depends on the memory type of the xdp_buff. For page pool based xdp_buff
it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy
XSK pool based xdp_buff it produces xdp_frame with memory type
MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the
memory type and always uses the page pool type, this leads to invalid
mappings and causes the crash. Therefore, check the xdp_buff memory type
in stmmac_xdp_xmit_back() to fix this issue.
CVSS Score
9.1
EPSS Score
0.002
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
Input: lkkbd - disable pending work before freeing device
lkkbd_interrupt() schedules lk->tq via schedule_work(), and the work
handler lkkbd_reinit() dereferences the lkkbd structure and its
serio/input_dev fields.
lkkbd_disconnect() and error paths in lkkbd_connect() free the lkkbd
structure without preventing the reinit work from being queued again
until serio_close() returns. This can allow the work handler to run
after the structure has been freed, leading to a potential use-after-free.
Use disable_work_sync() instead of cancel_work_sync() to ensure the
reinit work cannot be re-queued, and call it both in lkkbd_disconnect()
and in lkkbd_connect() error paths after serio_open().
CVSS Score
7.8
EPSS Score
0.001
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
functionfs: fix the open/removal races
ffs_epfile_open() can race with removal, ending up with file->private_data
pointing to freed object.
There is a total count of opened files on functionfs (both ep0 and
dynamic ones) and when it hits zero, dynamic files get removed.
Unfortunately, that removal can happen while another thread is
in ffs_epfile_open(), but has not incremented the count yet.
In that case open will succeed, leaving us with UAF on any subsequent
read() or write().
The root cause is that ffs->opened is misused; atomic_dec_and_test() vs.
atomic_add_return() is not a good idea, when object remains visible all
along.
To untangle that
* serialize openers on ffs->mutex (both for ep0 and for dynamic files)
* have dynamic ones use atomic_inc_not_zero() and fail if we had
zero ->opened; in that case the file we are opening is doomed.
* have the inodes of dynamic files marked on removal (from the
callback of simple_recursive_removal()) - clear ->i_private there.
* have open of dynamic ones verify they hadn't been already removed,
along with checking that state is FFS_ACTIVE.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: delete radeon_fence_process in is_signaled, no deadlock
Delete the attempt to progress the queue when checking if fence is
signaled. This avoids deadlock.
dma-fence_ops::signaled can be called with the fence lock in unknown
state. For radeon, the fence lock is also the wait queue lock. This can
cause a self deadlock when signaled() tries to make forward progress on
the wait queue. But advancing the queue is unneeded because incorrectly
returning false from signaled() is perfectly acceptable.
(cherry picked from commit 527ba26e50ec2ca2be9c7c82f3ad42998a75d0db)
CVSS Score
5.5
EPSS Score
0.001
Published
2025-12-16
In the Linux kernel, the following vulnerability has been resolved:
devlink: rate: Unset parent pointer in devl_rate_nodes_destroy
The function devl_rate_nodes_destroy is documented to "Unset parent for
all rate objects". However, it was only calling the driver-specific
`rate_leaf_parent_set` or `rate_node_parent_set` ops and decrementing
the parent's refcount, without actually setting the
`devlink_rate->parent` pointer to NULL.
This leaves a dangling pointer in the `devlink_rate` struct, which cause
refcount error in netdevsim[1] and mlx5[2]. In addition, this is
inconsistent with the behavior of `devlink_nl_rate_parent_node_set`,
where the parent pointer is correctly cleared.
This patch fixes the issue by explicitly setting `devlink_rate->parent`
to NULL after notifying the driver, thus fulfilling the function's
documented behavior for all rate objects.
[1]
repro steps:
echo 1 > /sys/bus/netdevsim/new_device
devlink dev eswitch set netdevsim/netdevsim1 mode switchdev
echo 1 > /sys/bus/netdevsim/devices/netdevsim1/sriov_numvfs
devlink port function rate add netdevsim/netdevsim1/test_node
devlink port function rate set netdevsim/netdevsim1/128 parent test_node
echo 1 > /sys/bus/netdevsim/del_device
dmesg:
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 8 PID: 1530 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0
CPU: 8 UID: 0 PID: 1530 Comm: bash Not tainted 6.18.0-rc4+ #1 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:refcount_warn_saturate+0x42/0xe0
Call Trace:
<TASK>
devl_rate_leaf_destroy+0x8d/0x90
__nsim_dev_port_del+0x6c/0x70 [netdevsim]
nsim_dev_reload_destroy+0x11c/0x140 [netdevsim]
nsim_drv_remove+0x2b/0xb0 [netdevsim]
device_release_driver_internal+0x194/0x1f0
bus_remove_device+0xc6/0x130
device_del+0x159/0x3c0
device_unregister+0x1a/0x60
del_device_store+0x111/0x170 [netdevsim]
kernfs_fop_write_iter+0x12e/0x1e0
vfs_write+0x215/0x3d0
ksys_write+0x5f/0xd0
do_syscall_64+0x55/0x10f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
[2]
devlink dev eswitch set pci/0000:08:00.0 mode switchdev
devlink port add pci/0000:08:00.0 flavour pcisf pfnum 0 sfnum 1000
devlink port function rate add pci/0000:08:00.0/group1
devlink port function rate set pci/0000:08:00.0/32768 parent group1
modprobe -r mlx5_ib mlx5_fwctl mlx5_core
dmesg:
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 7 PID: 16151 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0
CPU: 7 UID: 0 PID: 16151 Comm: bash Not tainted 6.17.0-rc7_for_upstream_min_debug_2025_10_02_12_44 #1 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:refcount_warn_saturate+0x42/0xe0
Call Trace:
<TASK>
devl_rate_leaf_destroy+0x8d/0x90
mlx5_esw_offloads_devlink_port_unregister+0x33/0x60 [mlx5_core]
mlx5_esw_offloads_unload_rep+0x3f/0x50 [mlx5_core]
mlx5_eswitch_unload_sf_vport+0x40/0x90 [mlx5_core]
mlx5_sf_esw_event+0xc4/0x120 [mlx5_core]
notifier_call_chain+0x33/0xa0
blocking_notifier_call_chain+0x3b/0x50
mlx5_eswitch_disable_locked+0x50/0x110 [mlx5_core]
mlx5_eswitch_disable+0x63/0x90 [mlx5_core]
mlx5_unload+0x1d/0x170 [mlx5_core]
mlx5_uninit_one+0xa2/0x130 [mlx5_core]
remove_one+0x78/0xd0 [mlx5_core]
pci_device_remove+0x39/0xa0
device_release_driver_internal+0x194/0x1f0
unbind_store+0x99/0xa0
kernfs_fop_write_iter+0x12e/0x1e0
vfs_write+0x215/0x3d0
ksys_write+0x5f/0xd0
do_syscall_64+0x53/0x1f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
CVSS Score
7.8
EPSS Score
0.002
Published
2025-12-04
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: Fix race condition in RPC handle list access
The 'sess->rpc_handle_list' XArray manages RPC handles within a ksmbd
session. Access to this list is intended to be protected by
'sess->rpc_lock' (an rw_semaphore). However, the locking implementation was
flawed, leading to potential race conditions.
In ksmbd_session_rpc_open(), the code incorrectly acquired only a read lock
before calling xa_store() and xa_erase(). Since these operations modify
the XArray structure, a write lock is required to ensure exclusive access
and prevent data corruption from concurrent modifications.
Furthermore, ksmbd_session_rpc_method() accessed the list using xa_load()
without holding any lock at all. This could lead to reading inconsistent
data or a potential use-after-free if an entry is concurrently removed and
the pointer is dereferenced.
Fix these issues by:
1. Using down_write() and up_write() in ksmbd_session_rpc_open()
to ensure exclusive access during XArray modification, and ensuring
the lock is correctly released on error paths.
2. Adding down_read() and up_read() in ksmbd_session_rpc_method()
to safely protect the lookup.
CVSS Score
8.8
EPSS Score
0.003
Published
2025-10-28
In the Linux kernel, the following vulnerability has been resolved:
spi: cadence-quadspi: Implement refcount to handle unbind during busy
driver support indirect read and indirect write operation with
assumption no force device removal(unbind) operation. However
force device removal(removal) is still available to root superuser.
Unbinding driver during operation causes kernel crash. This changes
ensure driver able to handle such operation for indirect read and
indirect write by implementing refcount to track attached devices
to the controller and gracefully wait and until attached devices
remove operation completed before proceed with removal operation.
CVSS Score
5.5
EPSS Score
0.002
Published
2025-10-20
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd/pgtbl: Fix possible race while increase page table level
The AMD IOMMU host page table implementation supports dynamic page table levels
(up to 6 levels), starting with a 3-level configuration that expands based on
IOVA address. The kernel maintains a root pointer and current page table level
to enable proper page table walks in alloc_pte()/fetch_pte() operations.
The IOMMU IOVA allocator initially starts with 32-bit address and onces its
exhuasted it switches to 64-bit address (max address is determined based
on IOMMU and device DMA capability). To support larger IOVA, AMD IOMMU
driver increases page table level.
But in unmap path (iommu_v1_unmap_pages()), fetch_pte() reads
pgtable->[root/mode] without lock. So its possible that in exteme corner case,
when increase_address_space() is updating pgtable->[root/mode], fetch_pte()
reads wrong page table level (pgtable->mode). It does compare the value with
level encoded in page table and returns NULL. This will result is
iommu_unmap ops to fail and upper layer may retry/log WARN_ON.
CPU 0 CPU 1
------ ------
map pages unmap pages
alloc_pte() -> increase_address_space() iommu_v1_unmap_pages() -> fetch_pte()
pgtable->root = pte (new root value)
READ pgtable->[mode/root]
Reads new root, old mode
Updates mode (pgtable->mode += 1)
Since Page table level updates are infrequent and already synchronized with a
spinlock, implement seqcount to enable lock-free read operations on the read path.
CVSS Score
8.8
EPSS Score
0.001
Published
2025-10-09
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (xgene) Fix ioremap and memremap leak
Smatch reports:
drivers/hwmon/xgene-hwmon.c:757 xgene_hwmon_probe() warn:
'ctx->pcc_comm_addr' from ioremap() not released on line: 757.
This is because in drivers/hwmon/xgene-hwmon.c:701 xgene_hwmon_probe(),
ioremap and memremap is not released, which may cause a leak.
To fix this, ioremap and memremap is modified to devm_ioremap and
devm_memremap.
[groeck: Fixed formatting and subject]
CVSS Score
5.5
EPSS Score
0.001
Published
2025-10-07