CVE-2026-31474
can: isotp: fix tx.buf use-after-free in isotp_sendmsg()
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: can: isotp: fix tx.buf use-after-free in isotp_sendmsg() isotp_sendmsg() uses only cmpxchg() on so->tx.state to serialize access to so->tx.buf. isotp_release() waits for ISOTP_IDLE via wait_event_interruptible() and then calls kfree(so->tx.buf). If a signal interrupts the wait_event_interruptible() inside close() while tx.state is ISOTP_SENDING, the loop exits early and release proceeds to force ISOTP_SHUTDOWN and continues to kfree(so->tx.buf) while sendmsg may still be reading so->tx.buf for the final CAN frame in isotp_fill_dataframe(). The so->tx.buf can be allocated once when the standard tx.buf length needs to be extended. Move the kfree() of this potentially extended tx.buf to sk_destruct time when either isotp_sendmsg() and isotp_release() are done.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| redhat-SADPADP (enrichment) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.10% · top 99% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 96d1c81e6a0478535342dff6c730adb076cd84e8 – < cb3d6efa78460e6d50bf68806d0db66265709f64
- affected 96d1c81e6a0478535342dff6c730adb076cd84e8 – < 9649d051e54413049c009638ec1dc23962c884a4
- affected 96d1c81e6a0478535342dff6c730adb076cd84e8 – < eec8a1b18a79600bd4419079dc0026c1db72a830
- affected 96d1c81e6a0478535342dff6c730adb076cd84e8 – < 2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c
- affected 96d1c81e6a0478535342dff6c730adb076cd84e8 – < 424e95d62110cdbc8fd12b40918f37e408e35a92
- affected 6.4
- unaffected < 6.4
- unaffected 6.6.131 – ≤ 6.6.*
- unaffected 6.12.80 – ≤ 6.12.*
- unaffected 6.18.21 – ≤ 6.18.*
- unaffected 6.19.11 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References (11)
- https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64 (opens in a new tab)
- https://git.kernel.org/stable/c/9649d051e54413049c009638ec1dc23962c884a4 (opens in a new tab)
- https://git.kernel.org/stable/c/eec8a1b18a79600bd4419079dc0026c1db72a830 (opens in a new tab)
- https://git.kernel.org/stable/c/2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c (opens in a new tab)
- https://git.kernel.org/stable/c/424e95d62110cdbc8fd12b40918f37e408e35a92 (opens in a new tab)
- https://access.redhat.com/security/cve/CVE-2026-31474 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2460646 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31474.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:27731 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:27288 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:27789 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-31474)Record last updated .