soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read
Summary
| CVE | CVE-2026-74729 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-22 16:16:48 UTC |
| Updated | 2026-08-22 16:16:48 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read
put_fifo_with_discard() acts as both producer and consumer on the kfifo:
it calls kfifo_skip() (advances out) and kfifo_put() (advances in) from
the IRQ handler without synchronizing with snoop_file_read(), which also
consumes via kfifo_to_user(). On SMP systems this concurrent access can
leave (in - out) larger than the ring buffer, so __kfifo_to_user()'s clamp
to (in - out) is ineffective and kfifo_copy_to_user() can attempt a
copy_to_user() past the kmalloc-2k backing store:
usercopy: Kernel memory exposure attempt detected from SLUB object
'kmalloc-2k' (offset 0, size 2049)!
kernel BUG at mm/usercopy.c!
Call trace:
usercopy_abort
__check_heap_object
__check_object_size
kfifo_copy_to_user
__kfifo_to_user
snoop_file_read
vfs_read
Serialize kfifo access with a per-channel spinlock shared between the
IRQ handler (producer) and the file reader (consumer). Annotate @fifo
with __guarded_by(&lock) and opt the driver into context analysis so the
compiler enforces that all fifo access holds the lock. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 3772e5da445420543b25825ac2b5971f3743f6e8 131ab677b03349a5ae48da8722ec7075b37ec66e git |
Not specified |
| CNA |
Linux |
Linux |
affected 3772e5da445420543b25825ac2b5971f3743f6e8 1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f git |
Not specified |
| CNA |
Linux |
Linux |
affected 4.19 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 4.19 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1.9 7.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/131ab677b03349a5ae48da8722ec7075b37ec66e |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.