CVE-2026-74646
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke
When an invoke is interrupted by a signal,
wait_for_completion_interruptible() returns -ERESTARTSYS and
fastrpc_internal_invoke() moves every buffer from fl->mmaps onto
cctx->invoke_interrupted_mmaps. This list_del()/list_add_tail() walk
runs without holding fl->lock, the lock that serialises fl->mmaps in
fastrpc_req_mmap() and fastrpc_req_munmap() everywhere else.
Take fl->lock around the move, matching every other fl->mmaps accessor.
CSIRTS triage
- What
- Missing lock acquisition when moving mmaps during interrupted fastrpc invocation can cause concurrent memory modification.
- Who is affected
- Systems running vulnerable Linux kernel versions with fastrpc miscellaneous driver enabled.
- Urgency
- Medium priority; not currently exploited but race conditions on mmap lists can cause memory corruption.
- Action
- Apply kernel patch acquiring fl->lock during mmap relocation in drivers/misc/fastrpc.c or update to patched kernel version.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
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