can: bcm: add locking when updating filter and timer values
In the Linux kernel, the following vulnerability has been resolved: can: bcm: add locking when updating filter and timer values KCSAN detected a simultaneous access to timer values that can be overwritten in bcm_rx_setup() when updating timer and filter content while bcm_rx_handler(), bcm_rx_timeout_handler() or bcm_rx_thr_handler() run concurrently on incoming CAN traffic. Protect the timer (ival1/ival2/kt_ival1/kt_ival2/kt_lastmsg) and filter (nframes/flags/frames/last_frames) updates in bcm_rx_setup() with a new per-op bcm_rx_update_lock, taken with the matching scope in the RX handlers. memcpy_from_msg() is staged into a temporary buffer before the lock is taken, since it can sleep and must not run under a spinlock. hrtimer_cancel() is always called without bcm_rx_update_lock held, since bcm_rx_timeout_handler()/bcm_rx_thr_handler() take the same lock and a running callback would otherwise deadlock against the canceller. Also close a related race: bcm_rx_setup() cleared the RTR flag in the stored reply frame's can_id as a separate, unprotected step after the frame content was already installed, so a concurrent bcm_rx_handler() could transmit a stale reply with CAN_RTR_FLAG still set. Fold that normalization into the initial frame preparation instead (on the staged buffer for updates, directly on op->frames pre-registration for new ops), so the installed frame is always atomically self-consistent. bcm_rx_handler()'s RX_RTR_FRAME check now takes a lock-protected snapshot of
CVE-2026-72121
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-2026-72121
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": "7595de7bc56e0e52b74e56c90f7e247bf626d628",
"lessThan": "96994180bd7b248b0cc698afe926e23fc1bda59b",
"versionType": "git"
},
{
"status": "affected",
"version": "fbd8fdc2b218e979cfe422b139b8f74c12419d1f",
"lessThan": "caa8704a7f3cb7806331596195385437126ecb3a",
"versionType": "git"
},
{
"status": "affected",
"version": "2a437b86ac5a9893c902f30ef66815bf13587bf6",
"lessThan": "a7c369e7da8203e2b5be12bbcac7b9ab2ed5b658",
"versionType": "git"
},
{
"status": "affected",
"version": "76c84c3728178b2d38d5604e399dfe8b0752645e",
"lessThan": "a7eb6db1cd3f7b556a301dc1265945ad112089f7",
"versionType": "git"
},
{
"status": "affected",
"version": "cc55dd28c20a6611e30596019b3b2f636819a4c0",
"lessThan": "834cbca3b12e46887f7a9b35f1981a888360ea4c",
"versionType": "git"
},
{
"status": "affected",
"version": "c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7",
"lessThan": "19b1994069dd29478ba767de1f98f14a088198dc",
"versionType": "git"
},
{
"status": "affected",
"version": "c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7",
"lessThan": "fc9f5ee1b073bd233d9c604e338af4ebb42cbc33",
"versionType": "git"
},
{
"status": "affected",
"version": "c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7",
"lessThan": "749179c2e25b95d22499ed29096b3e02d6dfd2b4",
"versionType": "git"
},
{
"status": "affected",
"version": "8f1c022541bf5a923c8d6fa483112c15250f30a4",
"versionType": "git"
},
{
"status": "affected",
"version": "c4e8a172501e677ebd8ea9d9161d97dc4df56fbd",
"versionType": "git"
},
{
"status": "affected",
"version": "5.10.238",
"lessThan": "5.10.265",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.15.185",
"lessThan": "5.15.216",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.141",
"lessThan": "6.1.183",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.93",
"lessThan": "6.6.148",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.31",
"lessThan": "6.12.101",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.294",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.14.9",
"lessThan": "6.15",
"versionType": "semver"
}
],
"programFiles": [
"net/can/bcm.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/can/bcm.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-72121
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #32948 · Revision 1
- Added to Heist Feed
- Publisher date