CVE-2026-74729
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.
CSIRTS triage
- What
- The Aspeed LPC snoop snoop_file_read function has a usercopy buffer overflow.
- Who is affected
- Systems running affected Linux kernel versions with Aspeed SOC LPC snoop functionality.
- Urgency
- Medium severity (CVSS 6.3); not currently exploited but enables privilege escalation via usercopy overflow.
- Action
- Update to a patched Linux kernel version addressing CVE-2026-74729.
AI-assisted analysis generated from the source advisory — verify against the original.
⚡ Watch CVE-2026-74729
Get an email if CVE-2026-74729 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.
Exploitation outlook
- Low exploitation risk0.17% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
Embed the live status
— this badge updates automatically when the KEV or exploit status changes. How to embed it →
[](https://www.csirts.com/cve/CVE-2026-74729)