Security Vulnerabilities
- CVEs Published In August 2025
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: uvc: Initialize frame-based format color matching descriptor
Fix NULL pointer crash in uvcg_framebased_make due to uninitialized color
matching descriptor for frame-based format which was added in
commit f5e7bdd34aca ("usb: gadget: uvc: Allow creating new color matching
descriptors") that added handling for uncompressed and mjpeg format.
Crash is seen when userspace configuration (via configfs) does not
explicitly define the color matching descriptor. If color_matching is not
found, config_group_find_item() returns NULL. The code then jumps to
out_put_cm, where it calls config_item_put(color_matching);. If
color_matching is NULL, this will dereference a null pointer, leading to a
crash.
[ 2.746440] Unable to handle kernel NULL pointer dereference at virtual address 000000000000008c
[ 2.756273] Mem abort info:
[ 2.760080] ESR = 0x0000000096000005
[ 2.764872] EC = 0x25: DABT (current EL), IL = 32 bits
[ 2.771068] SET = 0, FnV = 0
[ 2.771069] EA = 0, S1PTW = 0
[ 2.771070] FSC = 0x05: level 1 translation fault
[ 2.771071] Data abort info:
[ 2.771072] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
[ 2.771073] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 2.771074] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 2.771075] user pgtable: 4k pages, 39-bit VAs, pgdp=00000000a3e59000
[ 2.771077] [000000000000008c] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
[ 2.771081] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
[ 2.771084] Dumping ftrace buffer:
[ 2.771085] (ftrace buffer empty)
[ 2.771138] CPU: 7 PID: 486 Comm: ln Tainted: G W E 6.6.58-android15
[ 2.771139] Hardware name: Qualcomm Technologies, Inc. SunP QRD HDK (DT)
[ 2.771140] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 2.771141] pc : __uvcg_fill_strm+0x198/0x2cc
[ 2.771145] lr : __uvcg_iter_strm_cls+0xc8/0x17c
[ 2.771146] sp : ffffffc08140bbb0
[ 2.771146] x29: ffffffc08140bbb0 x28: ffffff803bc81380 x27: ffffff8023bbd250
[ 2.771147] x26: ffffff8023bbd250 x25: ffffff803c361348 x24: ffffff803d8e6768
[ 2.771148] x23: 0000000000000004 x22: 0000000000000003 x21: ffffffc08140bc48
[ 2.771149] x20: 0000000000000000 x19: ffffffc08140bc48 x18: ffffffe9f8cf4a00
[ 2.771150] x17: 000000001bf64ec3 x16: 000000001bf64ec3 x15: ffffff8023bbd250
[ 2.771151] x14: 000000000000000f x13: 004c4b40000f4240 x12: 000a2c2a00051615
[ 2.771152] x11: 000000000000004f x10: ffffffe9f76b40ec x9 : ffffffe9f7e389d0
[ 2.771153] x8 : ffffff803d0d31ce x7 : 000f4240000a2c2a x6 : 0005161500028b0a
[ 2.771154] x5 : ffffff803d0d31ce x4 : 0000000000000003 x3 : 0000000000000000
[ 2.771155] x2 : ffffffc08140bc50 x1 : ffffffc08140bc48 x0 : 0000000000000000
[ 2.771156] Call trace:
[ 2.771157] __uvcg_fill_strm+0x198/0x2cc
[ 2.771157] __uvcg_iter_strm_cls+0xc8/0x17c
[ 2.771158] uvcg_streaming_class_allow_link+0x240/0x290
[ 2.771159] configfs_symlink+0x1f8/0x630
[ 2.771161] vfs_symlink+0x114/0x1a0
[ 2.771163] do_symlinkat+0x94/0x28c
[ 2.771164] __arm64_sys_symlinkat+0x54/0x70
[ 2.771164] invoke_syscall+0x58/0x114
[ 2.771166] el0_svc_common+0x80/0xe0
[ 2.771168] do_el0_svc+0x1c/0x28
[ 2.771169] el0_svc+0x3c/0x70
[ 2.771172] el0t_64_sync_handler+0x68/0xbc
[ 2.771173] el0t_64_sync+0x1a8/0x1ac
Initialize color matching descriptor for frame-based format to prevent
NULL pointer crash by mirroring the handling done for uncompressed and
mjpeg formats.
In the Linux kernel, the following vulnerability has been resolved:
platform/x86/intel/pmt: fix a crashlog NULL pointer access
Usage of the intel_pmt_read() for binary sysfs, requires a pcidev. The
current use of the endpoint value is only valid for telemetry endpoint
usage.
Without the ep, the crashlog usage causes the following NULL pointer
exception:
BUG: kernel NULL pointer dereference, address: 0000000000000000
Oops: Oops: 0000 [#1] SMP NOPTI
RIP: 0010:intel_pmt_read+0x3b/0x70 [pmt_class]
Code:
Call Trace:
<TASK>
? sysfs_kf_bin_read+0xc0/0xe0
kernfs_fop_read_iter+0xac/0x1a0
vfs_read+0x26d/0x350
ksys_read+0x6b/0xe0
__x64_sys_read+0x1d/0x30
x64_sys_call+0x1bc8/0x1d70
do_syscall_64+0x6d/0x110
Augment struct intel_pmt_entry with a pointer to the pcidev to avoid
the NULL pointer exception.
In the Linux kernel, the following vulnerability has been resolved:
x86/sev: Evict cache lines during SNP memory validation
An SNP cache coherency vulnerability requires a cache line eviction
mitigation when validating memory after a page state change to private.
The specific mitigation is to touch the first and last byte of each 4K
page that is being validated. There is no need to perform the mitigation
when performing a page state change to shared and rescinding validation.
CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit
that, when set, indicates that the software mitigation for this
vulnerability is not needed.
Implement the mitigation and invoke it when validating memory (making it
private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP
guest is vulnerable.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix Preauh_HashValue race condition
If client send multiple session setup requests to ksmbd,
Preauh_HashValue race condition could happen.
There is no need to free sess->Preauh_HashValue at session setup phase.
It can be freed together with session at connection termination phase.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix null pointer dereference error in generate_encryptionkey
If client send two session setups with krb5 authenticate to ksmbd,
null pointer dereference error in generate_encryptionkey could happen.
sess->Preauth_HashValue is set to NULL if session is valid.
So this patch skip generate encryption key if session is valid.
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Prevent VMA split of buffer mappings
The perf mmap code is careful about mmap()'ing the user page with the
ringbuffer and additionally the auxiliary buffer, when the event supports
it. Once the first mapping is established, subsequent mapping have to use
the same offset and the same size in both cases. The reference counting for
the ringbuffer and the auxiliary buffer depends on this being correct.
Though perf does not prevent that a related mapping is split via mmap(2),
munmap(2) or mremap(2). A split of a VMA results in perf_mmap_open() calls,
which take reference counts, but then the subsequent perf_mmap_close()
calls are not longer fulfilling the offset and size checks. This leads to
reference count leaks.
As perf already has the requirement for subsequent mappings to match the
initial mapping, the obvious consequence is that VMA splits, caused by
resizing of a mapping or partial unmapping, have to be prevented.
Implement the vm_operations_struct::may_split() callback and return
unconditionally -EINVAL.
That ensures that the mapping offsets and sizes cannot be changed after the
fact. Remapping to a different fixed address with the same size is still
possible as it takes the references for the new mapping and drops those of
the old mapping.
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Handle buffer mapping fail correctly in perf_mmap()
After successful allocation of a buffer or a successful attachment to an
existing buffer perf_mmap() tries to map the buffer read only into the page
table. If that fails, the already set up page table entries are zapped, but
the other perf specific side effects of that failure are not handled. The
calling code just cleans up the VMA and does not invoke perf_mmap_close().
This leaks reference counts, corrupts user->vm accounting and also results
in an unbalanced invocation of event::event_mapped().
Cure this by moving the event::event_mapped() invocation before the
map_range() call so that on map_range() failure perf_mmap_close() can be
invoked without causing an unbalanced event::event_unmapped() call.
perf_mmap_close() undoes the reference counts and eventually frees buffers.
In the Linux kernel, the following vulnerability has been resolved:
mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped
By inducing delays in the right places, Jann Horn created a reproducer for
a hard to hit UAF issue that became possible after VMAs were allowed to be
recycled by adding SLAB_TYPESAFE_BY_RCU to their cache.
Race description is borrowed from Jann's discovery report:
lock_vma_under_rcu() looks up a VMA locklessly with mas_walk() under
rcu_read_lock(). At that point, the VMA may be concurrently freed, and it
can be recycled by another process. vma_start_read() then increments the
vma->vm_refcnt (if it is in an acceptable range), and if this succeeds,
vma_start_read() can return a recycled VMA.
In this scenario where the VMA has been recycled, lock_vma_under_rcu()
will then detect the mismatching ->vm_mm pointer and drop the VMA through
vma_end_read(), which calls vma_refcount_put(). vma_refcount_put() drops
the refcount and then calls rcuwait_wake_up() using a copy of vma->vm_mm.
This is wrong: It implicitly assumes that the caller is keeping the VMA's
mm alive, but in this scenario the caller has no relation to the VMA's mm,
so the rcuwait_wake_up() can cause UAF.
The diagram depicting the race:
T1 T2 T3
== == ==
lock_vma_under_rcu
mas_walk
<VMA gets removed from mm>
mmap
<the same VMA is reallocated>
vma_start_read
__refcount_inc_not_zero_limited_acquire
munmap
__vma_enter_locked
refcount_add_not_zero
vma_end_read
vma_refcount_put
__refcount_dec_and_test
rcuwait_wait_event
<finish operation>
rcuwait_wake_up [UAF]
Note that rcuwait_wait_event() in T3 does not block because refcount was
already dropped by T1. At this point T3 can exit and free the mm causing
UAF in T1.
To avoid this we move vma->vm_mm verification into vma_start_read() and
grab vma->vm_mm to stabilize it before vma_refcount_put() operation.
[surenb@google.com: v3]
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget : fix use-after-free in composite_dev_cleanup()
1. In func configfs_composite_bind() -> composite_os_desc_req_prepare():
if kmalloc fails, the pointer cdev->os_desc_req will be freed but not
set to NULL. Then it will return a failure to the upper-level function.
2. in func configfs_composite_bind() -> composite_dev_cleanup():
it will checks whether cdev->os_desc_req is NULL. If it is not NULL, it
will attempt to use it.This will lead to a use-after-free issue.
BUG: KASAN: use-after-free in composite_dev_cleanup+0xf4/0x2c0
Read of size 8 at addr 0000004827837a00 by task init/1
CPU: 10 PID: 1 Comm: init Tainted: G O 5.10.97-oh #1
kasan_report+0x188/0x1cc
__asan_load8+0xb4/0xbc
composite_dev_cleanup+0xf4/0x2c0
configfs_composite_bind+0x210/0x7ac
udc_bind_to_driver+0xb4/0x1ec
usb_gadget_probe_driver+0xec/0x21c
gadget_dev_desc_UDC_store+0x264/0x27c
In the Linux kernel, the following vulnerability has been resolved:
HID: core: Harden s32ton() against conversion to 0 bits
Testing by the syzbot fuzzer showed that the HID core gets a
shift-out-of-bounds exception when it tries to convert a 32-bit
quantity to a 0-bit quantity. Ideally this should never occur, but
there are buggy devices and some might have a report field with size
set to zero; we shouldn't reject the report or the device just because
of that.
Instead, harden the s32ton() routine so that it returns a reasonable
result instead of crashing when it is called with the number of bits
set to 0 -- the same as what snto32() does.