CVE-2025-39713

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

MEDIUM 4.7

At a glance

Source
NVD
EPSS
EPSS 0.14 % · percentile 3 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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.

Weaknesses (CWE)

  • CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac < 2964dbe631fd21ad7873b1752b895548d3c12496 ; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac < 6aaef1a75985865d8c6c5b65fb54152060faba48 ; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac < fbc81e78d75bf28972bc22b1599559557b1a1b83 ; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac < 3c3e33b7edca7a2d6a96801f287f9faeb684d655 ; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac < 1c2769dc80255824542ea5a4ff1a07dcdeb1603f ; affected 0f314f6c2e77beb1a232be21dd6be4e1849ba5ac < ed905fe7cba03cf22ae0b84cf1b73cd1c070423a
Linux · Linuxaffected 4.12 ; unaffected 0 < 4.12 ; unaffected 5.4.297 ≤ 5.4.* ; unaffected 5.10.241 ≤ 5.10.* ; unaffected 5.15.190 ≤ 5.15.* ; unaffected 6.1.149 ≤ 6.1.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD