Linux: >> Linux Kernel >> 6.11 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()
pwrseq_debugfs_seq_next() declares 'next' with __free(put_device),
which causes put_device() to be called on the returned pointer when
the variable goes out of scope. This results in a use-after-free
since the seq_file framework receives a pointer whose reference has
already been dropped.
Simply removing __free(put_device) would fix the UAF but would leak
the reference acquired by bus_find_next_device(), as stop() only
calls up_read(&pwrseq_sem) and never releases the device reference.
Fix this by making the reference counting consistent across all
seq_file callbacks, matching the standard pattern used by PCI and
SCSI:
- start(): use get_device() so it returns a referenced pointer.
- next(): explicitly put_device(curr) to release the previous
device's reference (no NULL check needed - the seq_file framework
only calls next() while the previous return was non-NULL).
- stop(): put_device(data) to release the last iterated device's
reference, with a NULL guard since stop() may be called with NULL
when start() returned NULL or next() reached end-of-sequence.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
MIPS: DEC: Prevent initial console buffer from landing in XKPHYS
In 64-bit configurations calling the initial console output handler from
a kernel thread other than the initial one will result in a situation
where the stack has been placed in the XKPHYS 64-bit memory segment and
consequently so has been the buffer allocated there that is used as the
argument corresponding to the `%s' output conversion specifier for the
firmware's printf() entry point.
This 64-bit address will then be truncated by 32-bit firmware, resulting
in an attempt to access the wrong memory location, which in turn will
cause all kinds of unpredictable behaviour, such as a kernel crash:
Console: colour dummy device 160x64
Calibrating delay loop... 49.36 BogoMIPS (lpj=192512)
pid_max: default: 32768 minimum: 301
CPU 0 Unable to handle kernel paging request at virtual address 000000000203bd00, epc == ffffffffbfc08364, ra == ffffffffbfc08800
Oops[#1]:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.18.0-rc2-00254-gfb649bda6f56-dirty #121
$ 0 : 0000000000000000 0000000000000001 0000000000000023 ffffffff80684ba0
$ 4 : 000000000203bd00 ffffffffbfc0f3b4 ffffffffffffffff 0000000000000073
$ 8 : 0a303d7469000000 0000000000000000 0000000000000073 ffffffffbfc0f473
$12 : 0000000000000002 0000000000000000 ffffffff80684c1c 0000000000000000
$16 : 0000000000000000 ffffffff80596dc9 0000000000000000 ffffffffbfc09240
$20 : ffffffff80684c40 ffffffffbfc0f400 000000000000002d 000000000000002b
$24 : ffffffffffffffbf 000000000203bd00
$28 : ffffffff805f0000 ffffffff80684b58 0000000000000030 ffffffffbfc08800
Hi : 0000000000000000
Lo : 0000000000000aa8
epc : ffffffffbfc08364 0xffffffffbfc08364
ra : ffffffffbfc08800 0xffffffffbfc08800
Status: 140120e2 KX SX UX KERNEL EXL
Cause : 00000008 (ExcCode 02)
BadVA : 000000000203bd00
PrId : 00000430 (R4000SC)
Modules linked in:
Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____), tls=0000000000000000)
Stack : 0000000000000000 0000000000000000 0000000000000000 0000004d0000004d
80684cc0806a2a40 80596dc80000004d 8061000000000000 bfc0850c80684c38
0000000000000000 000000000203bd00 0000000000000000 0000000000000000
0000000000000000 00000000bfc0f3b4 0000000000000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000002500000000 0000000000000000 0000000000000000 802c1a7400000000
0203bd0080596dc8 0203bd4d69000000 6c61632000000018 5f746567646e6172
6c616320625f6d6f 5f736e5f6d6f7266 206361323778302b 303d74696e726320
806a0a38806b0000 806a0a38806b0000 00000000806b0000 80683c58806b0000
...
Call Trace:
Code: a082ffff 03e00008 00601021 <80820000> 00001821 10400005 24840001 80820000 24630001
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception in interrupt
KN04 V2.1k (PC: 0xa0026768, SP: 0x806848e8)
>>
In this case the pointer in $4 was truncated from 0x980000000203bd00 to
0x000000000203bd00.
This may happen when no final console driver has been enabled in the
configuration and consequently the initial console continues being used
late into bootstrap or with an upcoming change that will switch the zs
driver to use a platform device, which in turn will make the console
handover happen only after other kernel threads have already been
started.
Fix the issue by making the buffer static and initdata, and therefore
placed in the CKSEG0 32-bit compatibility segment, observing that the
console output handler is called with the console lock held, implying
no need for this code to be reentrant. Add an assertion to verify the
buffer actually has been placed in a compatibility segment.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs-schemes: delete tried region in regions_rmdirs()
DAMON sysfs maintains the DAMOS tried region directory objects via a
linked list. When the user requests refresh of the directories, DAMON
sysfs removes all the region directories first, and then generate updated
regions directory on the empty space. The removal function
(damon_sysfs_scheme_regions_rm_dirs()) only puts the kobj objects.
Deletion of the container region object from the linked list is done
inside the kobj release callback function.
If somehow the callback invocation is delayed, the list will contain
regions list that gonna be freed. If the updated region directories
creation is started in this situation, the list can be corrupted and
use-after-free can happen.
Because the kobj objects are managed by only DAMON sysfs, the issue cannot
happen in normal situation. But, such delays can be made on kernels that
built with CONFIG_DEBUG_KOBJECT_RELEASE. On the kernel, the issue can
indeed be reproduced like below.
# damo start --damos_action stat
# cd /sys/kernel/mm/damon/admin/kdamonds/0/
# for i in {1..10}; do echo update_schemes_tried_regions > state; done
# dmesg | grep underflow
[ 89.296152] refcount_t: underflow; use-after-free.
Fix the issue by removing the region object from the list when
decrementing the reference count.
Also update damos_sysfs_populate_region_dir() to add the region object to
the list only after the kobject_init_and_add() is success, so that fail of
kobject_init_and_add() is not leaving the deallocated object on the list.
The issue was discovered [1] by Sashiko.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
gpio: rockchip: teardown bugs and resource leaks
Address several teardown issues and resource leaks in the driver's remove
path and error handling:
1. Debounce clock reference leak: The debounce clock (bank->db_clk) is
obtained using of_clk_get() which increments the clock's reference
count, but clk_put() is never called. Register a devm action to
cleanly release it on unbind. Note that of_clk_get(..., 1) remains
necessary over devm_clk_get() because the DT binding does not define
clock-names, precluding name-based lookup.
2. Unregistered chained IRQ handler: The chained IRQ handler is not
disconnected in remove(). If a stray interrupt fires after the driver
is removed, the kernel attempts to execute a stale handler, leading
to a panic. Fix this by clearing the handler in remove().
3. IRQ domain leak: The linear IRQ domain and its generic chips are
allocated manually during probe but never removed. Remove the IRQ
domain during driver teardown to free the associated generic chips
and mappings.
[Bartosz: don't emit an error message on devres allocation failure]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: net2280: Fix double free in probe error path
usb_initialize_gadget() installs gadget_release() as the release
callback for the embedded gadget device. The struct net2280 instance is
therefore released through gadget_release() when the gadget device's last
reference is dropped.
The probe error path calls net2280_remove(), which tears down the
partially initialized device and drops the gadget reference with
usb_put_gadget(). Calling kfree(dev) afterwards can free the same object
again.
Drop the explicit kfree() and let the gadget device release callback
handle the final free. This issue was found by a static analysis tool
I am developing.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dsi: don't dump registers past the mapped region
On DSI 6G platforms the IO address space is internally adjusted by
io_offset. Later this adjusted address might be used for memory dumping.
However the size that is used for memory dumping isn't adjusted to
account for the io_offset, leading to the potential access to the
unmapped region. Lower ctrl_size by the io_offset value to prevent
access past the mapped area.
msm_disp_snapshot_add_block+0x1d4/0x3c8 [msm] (P)
msm_dsi_host_snapshot+0x4c/0x78 [msm]
msm_dsi_snapshot+0x28/0x50 [msm]
msm_disp_snapshot_capture_state+0x74/0x140 [msm]
msm_disp_snapshot_state_sync+0x60/0x90 [msm]
_msm_disp_snapshot_work+0x30/0x90 [msm]
kthread_worker_fn+0xdc/0x460
kthread+0x120/0x140
Patchwork: https://patchwork.freedesktop.org/patch/721747/
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: uvc: hold opts->lock across XU walks in uvc_function_bind
uvc_function_bind() walks &opts->extension_units twice without holding
opts->lock:
- directly, for the iExtension string-descriptor fixup loop;
- indirectly, four times via uvc_copy_descriptors() (once per speed),
where the helper iterates uvc->desc.extension_units (which aliases
&opts->extension_units) to size and emit XU descriptors.
The configfs side (uvcg_extension_make / uvcg_extension_drop, in
drivers/usb/gadget/function/uvc_configfs.c) takes opts->lock around its
list_add_tail / list_del operations. A privileged userspace process
that holds the configfs subtree open and writes the gadget UDC name
to bind the function while concurrently rmdir()'ing an extensions
subdir can race uvcg_extension_drop() against the bind-time list walks
and dereference a freed struct uvcg_extension.
Hold opts->lock from the start of the XU string-descriptor fixup
through the last uvc_copy_descriptors() call, releasing on the
descriptor-error path via a new error_unlock label that drops the
lock before falling through to the existing error label. This
matches the locking discipline of the configfs callbacks and removes
the only remaining unsynchronised reader of the XU list during bind.
Reachability: only privileged processes that can mount configfs and
write to gadget UDC files can trigger the race, so this is a
correctness fix rather than a security boundary.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
tty: serial: pch_uart: add check for dma_alloc_coherent()
Add a check for dma_alloc_coherent() failure to prevent a potential
NULL pointer dereference in dma_handle_rx(). Properly release DMA
channels and the PCI device reference using a goto ladder if the
allocation fails.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
x86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines
With CONFIG_CALL_DEPTH_TRACKING enabled on an x86 retbleed-affected platform
(eg: Skylake), with retbleed=stuff, registering a dynamic ftrace trampoline
crashes on the first call into the traced function:
BUG: unable to handle page fault for address: ffff88817ae18880
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 4b53067 P4D 4b53067 PUD 0
Oops: Oops: 0002 [#1] SMP PTI
CPU: 3 UID: 0 PID: 187 Comm: usleep Not tainted 7.0.10 #243 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014
Code: 24 78 00 00 00 00 48 89 ea 48 89 54 24 20 48 8b b4 24 b8 00 00 00 48 8b bc 24 b0 00 00 00 48 89 bc 24 80 00 00 00 48 83 ef 05 <65> 48 c1 3d 1f a8 b6 02 05 48 8b 15 f6 00 00 00 4c 89 3c 24 4c 89
Call Trace:
<TASK>
? find_held_lock
? exc_page_fault
? lock_release
? __x64_sys_clock_nanosleep
? lockdep_hardirqs_on_prepare
? trace_hardirqs_on
__x64_sys_clock_nanosleep
do_syscall_64
? exc_page_fault
? call_depth_return_thunk
entry_SYSCALL_64_after_hwframe
...
Kernel panic - not syncing: Fatal exception
This small reproducer allows to easily trigger the crash:
# echo 'p __x64_sys_clock_nanosleep' > /sys/kernel/tracing/kprobe_events
# echo 1 > /sys/kernel/tracing/events/kprobes/p___x64_sys_clock_nanosleep_0/enable
# usleep 1
Monitoring the crash under GDB points to the exact instruction in charge of
incrementing the call depth:
sarq $5, %gs:__x86_call_depth(%rip)
This instruction matches the one inserted by the ftrace_regs_caller from
ftrace_64.S. This emitted code was likely working fine until the introduction
of
59bec00ace28 ("x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()"):
it has made the call depth accounting addressing relative to $rip, instead of
being based on an absolute address.
As this code exact location depends on where the trampoline lives in memory,
the corresponding displacement needs to be adjusted at runtime to actually
correctly find the per-cpu __x86_call_depth value, otherwise the targeted
address is wrong, leading to the page fault seen above.
Fix the %rip-relative displacement of the copied CALL_DEPTH_ACCOUNT
instruction (from ftrace_regs_caller) by calling text_poke_apply_relocation(),
as it is done for example by the x86 BPF JIT compiler through
x86_call_depth_emit_accounting(). This corrects both CALL_DEPTH_ACCOUNT slots,
in ftrace_caller and ftrace_regs_caller.
[ bp: Massage. ]
CVSS Score
8.1
EPSS Score
0.003
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
Input: elan_i2c - validate firmware size before use
Ensure that the firmware file is large enough to contain the expected
number of pages and the signature (which resides at the end of the
firmware blob) before accessing them to prevent potential out-of-bounds
reads.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-24