Description
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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < 2964dbe631fd21ad7873b1752b895548d3c12496affected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < 6aaef1a75985865d8c6c5b65fb54152060faba48affected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < fbc81e78d75bf28972bc22b1599559557b1a1b83affected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < 3c3e33b7edca7a2d6a96801f287f9faeb684d655affected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < 1c2769dc80255824542ea5a4ff1a07dcdeb1603faffected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < ed905fe7cba03cf22ae0b84cf1b73cd1c070423aaffected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < ff9dd3db6cd4c6b54a2ecbc58151bea4ec63bc59affected0f314f6c2e77beb1a232be21dd6be4e1849ba5ac to < 7af160aea26c7dc9e6734d19306128cce156ec40affected
Linux Linux
Default version status: affected
4.12affected0 to < 4.12unaffected5.4.297 to ≤ 5.4.*unaffected5.10.241 to ≤ 5.10.*unaffected5.15.190 to ≤ 5.15.*unaffected6.1.149 to ≤ 6.1.*unaffected6.6.103 to ≤ 6.6.*unaffected6.12.44 to ≤ 6.12.*unaffected6.16.4 to ≤ 6.16.*unaffected6.17 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/2964dbe631fd21ad7873b1752b895548d3c12496 ↗
- https://git.kernel.org/stable/c/6aaef1a75985865d8c6c5b65fb54152060faba48 ↗
- https://git.kernel.org/stable/c/fbc81e78d75bf28972bc22b1599559557b1a1b83 ↗
- https://git.kernel.org/stable/c/3c3e33b7edca7a2d6a96801f287f9faeb684d655 ↗
- https://git.kernel.org/stable/c/1c2769dc80255824542ea5a4ff1a07dcdeb1603f ↗
- https://git.kernel.org/stable/c/ed905fe7cba03cf22ae0b84cf1b73cd1c070423a ↗
- https://git.kernel.org/stable/c/ff9dd3db6cd4c6b54a2ecbc58151bea4ec63bc59 ↗
- https://git.kernel.org/stable/c/7af160aea26c7dc9e6734d19306128cce156ec40 ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html ↗
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html ↗