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CVE-2025-39713

media: rainshadow-cec: fix TOCTOU race condition in rain_interrupt() PUBLISHED

Description (CNA)

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 (CNA)

Vendor / productVersions
Linux / Linuxaffected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before 2964dbe631fd21ad7873b1752b895548d3c12496; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before 6aaef1a75985865d8c6c5b65fb54152060faba48; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before fbc81e78d75bf28972bc22b1599559557b1a1b83; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before 3c3e33b7edca7a2d6a96801f287f9faeb684d655; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before 1c2769dc80255824542ea5a4ff1a07dcdeb1603f; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before ed905fe7cba03cf22ae0b84cf1b73cd1c070423a; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before ff9dd3db6cd4c6b54a2ecbc58151bea4ec63bc59; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac before 7af160aea26c7dc9e6734d19306128cce156ec40
Linux / Linuxaffected 4.12; unaffected 0 before 4.12; unaffected 5.4.297 through 5.4.*; unaffected 5.10.241 through 5.10.*; unaffected 5.15.190 through 5.15.*; unaffected 6.1.149 through 6.1.*; unaffected 6.6.103 through 6.6.*; unaffected 6.12.44 through 6.12.*; unaffected 6.16.4 through 6.16.*; unaffected 6.17 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CVE

No English description supplied.

siemens-SADP

No English description supplied.