{"id":"CVE-2026-31474","summary":"can: isotp: fix tx.buf use-after-free in isotp_sendmsg()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: isotp: fix tx.buf use-after-free in isotp_sendmsg()\n\nisotp_sendmsg() uses only cmpxchg() on so-\u003etx.state to serialize access\nto so-\u003etx.buf. isotp_release() waits for ISOTP_IDLE via\nwait_event_interruptible() and then calls kfree(so-\u003etx.buf).\n\nIf a signal interrupts the wait_event_interruptible() inside close()\nwhile tx.state is ISOTP_SENDING, the loop exits early and release\nproceeds to force ISOTP_SHUTDOWN and continues to kfree(so-\u003etx.buf)\nwhile sendmsg may still be reading so-\u003etx.buf for the final CAN frame\nin isotp_fill_dataframe().\n\nThe so-\u003etx.buf can be allocated once when the standard tx.buf length needs\nto be extended. Move the kfree() of this potentially extended tx.buf to\nsk_destruct time when either isotp_sendmsg() and isotp_release() are done.","modified":"2026-06-23T15:29:21.482524914Z","published":"2026-04-22T13:54:03.100Z","related":["ALSA-2026:27789"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31474.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/424e95d62110cdbc8fd12b40918f37e408e35a92"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9649d051e54413049c009638ec1dc23962c884a4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eec8a1b18a79600bd4419079dc0026c1db72a830"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31474.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31474"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"96d1c81e6a0478535342dff6c730adb076cd84e8"},{"fixed":"cb3d6efa78460e6d50bf68806d0db66265709f64"},{"fixed":"9649d051e54413049c009638ec1dc23962c884a4"},{"fixed":"eec8a1b18a79600bd4419079dc0026c1db72a830"},{"fixed":"2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c"},{"fixed":"424e95d62110cdbc8fd12b40918f37e408e35a92"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31474.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.4.0"},{"fixed":"6.6.131"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.80"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.21"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31474.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}