CVE-2025-39713
In the Linux kernel, the following vulnerability has been resolved: media: rainshadow-cec: fix TOCTOU race condition in rain_interrupt() In the interrupt handler rain_interrupt(), the buffer full check on rain->buf_len is performed before acquiring rain->buf_lock. This creates a Time-of-Check to Time-of-Use (TOCTOU) race condition, as rain->buf_len is concurrently accessed and modified in the work handler rain_irq_work_handler() under the same lock. Multiple interrupt invocations can race, with each reading buf_len before it becomes full and then proceeding. This can lead to both interrupts attempting to write to the buffer, incrementing buf_len beyond its capacity (DATA_SIZE) and causing a buffer overflow. Fix this bug by moving the spin_lock() to before the buffer full check. This ensures that the check and the subsequent buffer modification are performed atomically, preventing the race condition. An corresponding spin_unlock() is added to the overflow path to correctly release the lock. This possible bug was found by an experimental static analysis tool developed by our team.
- CVSS 3.1
- 4.7
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 3% of CVEs (scores of 2026-10-25)
- CWE
- CWE-367
- Published
- Modified
- Record from
- the NVD, synced
Affected
- debian:debian_linux
- linux:linux_kernel
References
- https://git.kernel.org/stable/c/1c2769dc80255824542ea5a4ff1a07dcdeb1603f
- https://git.kernel.org/stable/c/2964dbe631fd21ad7873b1752b895548d3c12496
- https://git.kernel.org/stable/c/3c3e33b7edca7a2d6a96801f287f9faeb684d655
- https://git.kernel.org/stable/c/6aaef1a75985865d8c6c5b65fb54152060faba48
- https://git.kernel.org/stable/c/7af160aea26c7dc9e6734d19306128cce156ec40