can: isotp: fix tx.buf use-after-free in isotp_sendmsg()
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.
CVE-2026-31474
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-31474
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "96d1c81e6a0478535342dff6c730adb076cd84e8",
"lessThan": "cb3d6efa78460e6d50bf68806d0db66265709f64",
"versionType": "git"
},
{
"status": "affected",
"version": "96d1c81e6a0478535342dff6c730adb076cd84e8",
"lessThan": "9649d051e54413049c009638ec1dc23962c884a4",
"versionType": "git"
},
{
"status": "affected",
"version": "96d1c81e6a0478535342dff6c730adb076cd84e8",
"lessThan": "eec8a1b18a79600bd4419079dc0026c1db72a830",
"versionType": "git"
},
{
"status": "affected",
"version": "96d1c81e6a0478535342dff6c730adb076cd84e8",
"lessThan": "2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c",
"versionType": "git"
},
{
"status": "affected",
"version": "96d1c81e6a0478535342dff6c730adb076cd84e8",
"lessThan": "424e95d62110cdbc8fd12b40918f37e408e35a92",
"versionType": "git"
}
],
"programFiles": [
"net/can/isotp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.131",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.80",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.21",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.11",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/can/isotp.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-31474
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39889 · Revision 1
- Added to Heist Feed
- Publisher date