can: isotp: fix tx.buf use-after-free in isotp_sendmsg()
Priority LOW 35CWE-416Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00104 1st percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.6.131, 6.12.80, 6.18.21 +2Red Hat: 3 advisories
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.4 and later | 6.6.131, 6.12.80, 6.18.21, 6.19.11, 7.0 | Patch available | CNA |
- Linux VendorLinux Affected 6.4 and later Fixed in 6.6.131, 6.12.80, 6.18.21, 6.19.11, 7.0 Patch available CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.4.1 to before 6.6.131; 6.7 to before 6.12.80; 6.13 to before 6.18.21; 6.19 to before 6.19.11 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:* | 6.4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* | 7.0 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* | 7.0 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* | 7.0 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* | 7.0 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* | 7.0 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* | 7.0 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* | 7.0 rc7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.4.1 to before 6.6.131; 6.7 to before 6.12.80; 6.13 to before 6.18.21; 6.19 to before 6.19.11 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:* Versions 6.4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* Versions 7.0 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* Versions 7.0 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* Versions 7.0 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* Versions 7.0 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* Versions 7.0 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* Versions 7.0 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* Versions 7.0 rc7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.131, 6.12.80, 6.18.21, 6.19.11, 7.0
Red Hat 3 advisories
- RHSA-2026:27789 Released 2026-06-22 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.17.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.17.1.el9_8, kernel-64k-devel-5.14.0-687.17.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.17.1.el9_8, kernel-64k-5.14.0-687.17.1.el9_8, kernel-64k-core-5.14.0-687.17.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.17.1.el9_8, libperf-5.14.0-687.17.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.17.1.el9_8, kernel-rt-64k-5.14.0-687.17.1.el9_8, kernel-rt-64k-core-5.14.0-687.17.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.17.1.el9_8, kernel-rt-core-5.14.0-687.17.1.el9_8, kernel-rt-debug-5.14.0-687.17.1.el9_8 +9
- RHSA-2026:27731 Released 2026-06-22 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.82.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.82.1.el10_0, kernel-64k-devel-6.12.0-55.82.1.el10_0 +12
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.82.1.el10_0, kernel-64k-6.12.0-55.82.1.el10_0, kernel-64k-core-6.12.0-55.82.1.el10_0 +28
- Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.82.1.el10_0, libperf-6.12.0-55.82.1.el10_0
- Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.82.1.el10_0, kernel-rt-64k-6.12.0-55.82.1.el10_0, kernel-rt-64k-core-6.12.0-55.82.1.el10_0 +21
- Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.82.1.el10_0, kernel-rt-core-6.12.0-55.82.1.el10_0, kernel-rt-debug-6.12.0-55.82.1.el10_0 +11
- RHSA-2026:27288 Released 2026-06-20 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.26.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.26.1.el10_2, kernel-64k-devel-6.12.0-211.26.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.26.1.el10_2, kernel-64k-6.12.0-211.26.1.el10_2, kernel-64k-core-6.12.0-211.26.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.26.1.el10_2, libperf-6.12.0-211.26.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.26.1.el10_2, kernel-rt-64k-6.12.0-211.26.1.el10_2, kernel-rt-64k-core-6.12.0-211.26.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.26.1.el10_2, kernel-rt-core-6.12.0-211.26.1.el10_2, kernel-rt-debug-6.12.0-211.26.1.el10_2 +9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:27288 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:27789 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:27731 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:27288 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:27789 |
| Red Hat Enterprise Linux BaseOS EUS (v. 10.0) | Fixed | RHSA-2026:27731 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:27288 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:27789 |
| Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) | Fixed | RHSA-2026:27731 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:27288 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:27789 |
| Red Hat Enterprise Linux Real Time EUS (v. 10.0) | Fixed | RHSA-2026:27731 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:27288 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:27789 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) | Fixed | RHSA-2026:27731 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-31474
- 2026-10-03 Alias added: GHSA-6p7x-c5rv-9w7v
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 5
- https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64
- https://git.kernel.org/stable/c/9649d051e54413049c009638ec1dc23962c884a4
- https://git.kernel.org/stable/c/eec8a1b18a79600bd4419079dc0026c1db72a830
- https://git.kernel.org/stable/c/2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c
- https://git.kernel.org/stable/c/424e95d62110cdbc8fd12b40918f37e408e35a92
More Linux Kernel vulnerabilities
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-31474 · CVE Program
- CVE-2026-31474 · NVD
- FIRST EPSS
- GHSA-6p7x-c5rv-9w7v · GitHub Advisory Database · CC BY 4.0
- CVE-2026-31474 · Red Hat security data · CC BY 4.0
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