{"id":"CVE-2026-72120","state":"PUBLISHED","title":"can: bcm: add missing rcu list annotations and operations","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: add missing rcu list annotations and operations\n\nsashiko-bot remarked the missing use of list_add_rcu() in\nbcm_[rx|tx]_setup() to have a proper initialized bcm_op structure\nwhen bcm_proc_show() traverses the bcm_op's under rcu_read_lock().\n\nTo cover all initial settings of the bcm_op's the list_add_rcu() calls\nare moved to the end of the setup code.\n\nWhile at it, also fix the mirroring removal side: bcm_release() called\nbcm_remove_op() - which frees the op via call_rcu() - on ops that were\nstill linked in bo->tx_ops/bo->rx_ops, without list_del_rcu() first.\nUnlink each op with list_del_rcu() before handing it to bcm_remove_op(),\nmatching the existing pattern in bcm_delete_tx_op()/bcm_delete_rx_op().","publishedAt":"2026-08-15T05:52:59.226Z","updatedAt":"2026-10-16T18:44:57.136Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"659701c0b954ccdb4a916a4ad59bbc16e726d42c","status":"affected","lessThan":"8357255e56dc1aaa437e3c53ee9385de984e0d57","versionType":"git"},{"version":"0622846db728a5332b917c797c733e202c4620ae","status":"affected","lessThan":"8e1c7257c81577130f5ce90f69b2a2c3ce63f957","versionType":"git"},{"version":"6d7d458c41b98a5c1670cbd36f2923c37de51cf5","status":"affected","lessThan":"eb1c26eab4d1f0b4450439b4b88c3e73faf1da98","versionType":"git"},{"version":"1f912f8484e9c4396378c39460bbea0af681f319","status":"affected","lessThan":"f53bdab85e64eb57d6899a30d1307fd5a3639cc7","versionType":"git"},{"version":"63567ecd99a24495208dc860d50fb17440043006","status":"affected","lessThan":"4e22e8b505f877573bbdfdbcb680babad9b2f7a1","versionType":"git"},{"version":"dac5e6249159ac255dad9781793dbe5908ac9ddb","status":"affected","lessThan":"b06a4a397ac826603f39875cb7c7819a41365196","versionType":"git"},{"version":"dac5e6249159ac255dad9781793dbe5908ac9ddb","status":"affected","lessThan":"30f7bb922cb7e7f072a56c7cb7a5efccd2ceca1d","versionType":"git"},{"version":"dac5e6249159ac255dad9781793dbe5908ac9ddb","status":"affected","lessThan":"7b2c3eabc4dafc062a25e10711154f2107526a78","versionType":"git"},{"version":"19f553a1ddf260da6570ed8f8d91a8c87f49b63a","status":"affected","versionType":"git"},{"version":"7c9db92d5f0eadca30884af75c53d601edc512ee","status":"affected","versionType":"git"},{"version":"5.10.238","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.15.185","status":"affected","lessThan":"5.15.212","versionType":"semver"},{"version":"6.1.141","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.93","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.12.31","status":"affected","lessThan":"6.12.97","versionType":"semver"},{"version":"5.4.294","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"6.14.9","status":"affected","lessThan":"6.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/can/bcm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/can/bcm.c"]}],"references":["https://git.kernel.org/stable/c/8357255e56dc1aaa437e3c53ee9385de984e0d57","https://git.kernel.org/stable/c/8e1c7257c81577130f5ce90f69b2a2c3ce63f957","https://git.kernel.org/stable/c/eb1c26eab4d1f0b4450439b4b88c3e73faf1da98","https://git.kernel.org/stable/c/f53bdab85e64eb57d6899a30d1307fd5a3639cc7","https://git.kernel.org/stable/c/4e22e8b505f877573bbdfdbcb680babad9b2f7a1","https://git.kernel.org/stable/c/b06a4a397ac826603f39875cb7c7819a41365196","https://git.kernel.org/stable/c/30f7bb922cb7e7f072a56c7cb7a5efccd2ceca1d","https://git.kernel.org/stable/c/7b2c3eabc4dafc062a25e10711154f2107526a78"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72120.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72120","state":"PUBLISHED","datePublished":"2026-08-15T05:52:59.226Z","dateUpdated":"2026-10-16T18:44:57.136Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.907Z"},"containers":{"cna":{"title":"can: bcm: add missing rcu list annotations and operations","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: add missing rcu list annotations and operations\n\nsashiko-bot remarked the missing use of list_add_rcu() in\nbcm_[rx|tx]_setup() to have a proper initialized bcm_op structure\nwhen bcm_proc_show() traverses the bcm_op's under rcu_read_lock().\n\nTo cover all initial settings of the bcm_op's the list_add_rcu() calls\nare moved to the end of the setup code.\n\nWhile at it, also fix the mirroring removal side: bcm_release() called\nbcm_remove_op() - which frees the op via call_rcu() - on ops that were\nstill linked in bo->tx_ops/bo->rx_ops, without list_del_rcu() first.\nUnlink each op with list_del_rcu() before handing it to bcm_remove_op(),\nmatching the existing pattern in bcm_delete_tx_op()/bcm_delete_rx_op()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"659701c0b954ccdb4a916a4ad59bbc16e726d42c","status":"affected","lessThan":"8357255e56dc1aaa437e3c53ee9385de984e0d57","versionType":"git"},{"version":"0622846db728a5332b917c797c733e202c4620ae","status":"affected","lessThan":"8e1c7257c81577130f5ce90f69b2a2c3ce63f957","versionType":"git"},{"version":"6d7d458c41b98a5c1670cbd36f2923c37de51cf5","status":"affected","lessThan":"eb1c26eab4d1f0b4450439b4b88c3e73faf1da98","versionType":"git"},{"version":"1f912f8484e9c4396378c39460bbea0af681f319","status":"affected","lessThan":"f53bdab85e64eb57d6899a30d1307fd5a3639cc7","versionType":"git"},{"version":"63567ecd99a24495208dc860d50fb17440043006","status":"affected","lessThan":"4e22e8b505f877573bbdfdbcb680babad9b2f7a1","versionType":"git"},{"version":"dac5e6249159ac255dad9781793dbe5908ac9ddb","status":"affected","lessThan":"b06a4a397ac826603f39875cb7c7819a41365196","versionType":"git"},{"version":"dac5e6249159ac255dad9781793dbe5908ac9ddb","status":"affected","lessThan":"30f7bb922cb7e7f072a56c7cb7a5efccd2ceca1d","versionType":"git"},{"version":"dac5e6249159ac255dad9781793dbe5908ac9ddb","status":"affected","lessThan":"7b2c3eabc4dafc062a25e10711154f2107526a78","versionType":"git"},{"version":"19f553a1ddf260da6570ed8f8d91a8c87f49b63a","status":"affected","versionType":"git"},{"version":"7c9db92d5f0eadca30884af75c53d601edc512ee","status":"affected","versionType":"git"},{"version":"5.10.238","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.15.185","status":"affected","lessThan":"5.15.212","versionType":"semver"},{"version":"6.1.141","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.93","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.12.31","status":"affected","lessThan":"6.12.97","versionType":"semver"},{"version":"5.4.294","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"6.14.9","status":"affected","lessThan":"6.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/can/bcm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/can/bcm.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8357255e56dc1aaa437e3c53ee9385de984e0d57"},{"url":"https://git.kernel.org/stable/c/8e1c7257c81577130f5ce90f69b2a2c3ce63f957"},{"url":"https://git.kernel.org/stable/c/eb1c26eab4d1f0b4450439b4b88c3e73faf1da98"},{"url":"https://git.kernel.org/stable/c/f53bdab85e64eb57d6899a30d1307fd5a3639cc7"},{"url":"https://git.kernel.org/stable/c/4e22e8b505f877573bbdfdbcb680babad9b2f7a1"},{"url":"https://git.kernel.org/stable/c/b06a4a397ac826603f39875cb7c7819a41365196"},{"url":"https://git.kernel.org/stable/c/30f7bb922cb7e7f072a56c7cb7a5efccd2ceca1d"},{"url":"https://git.kernel.org/stable/c/7b2c3eabc4dafc062a25e10711154f2107526a78"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires local syscalls (socket/connect/sendmsg/close on PF_CAN/CAN_BCM) and/or reading /proc/net/can-bcm/<inode>; the bug is in RCU list management and procfs traversal, not in remote CAN frame reception.\nAC:L - The attacker controls both sides of the race—concurrent TX_SETUP/RX_SETUP or socket close while repeatedly reading the world-readable proc entry—so the UAF in bcm_proc_show is reliably triggerable without external timing luck.\nPR:L - PF_CAN CAN_BCM sockets are created and connected without capability checks; RX_SETUP works with ifindex 0 (no bound CAN device), so any unprivileged local user can create ops and race procfs reads on automotive, industrial, and embedded systems with CONFIG_CAN_BCM.\nUI:N - No victim interaction is required; the attacker drives the full exploit sequence (socket setup, opcode installation, proc reads, and socket teardown) from their own local process threads.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security domain; impact is local privilege escalation or crash, not crossing a VM, container, or IOMMU security boundary.\nC:H - bcm_proc_show dereferences bcm_op fields (can_id, flags, timers, counters) from list entries that may already be freed via call_rcu in bcm_remove_op, enabling kernel heap memory disclosure and further exploitation primitives.\nI:H - Freed bcm_op structures are kmalloc heap objects containing list_head links, sock pointers, and hrtimer state; UAF combined with heap spraying can yield arbitrary kernel writes and control-flow hijack for privilege escalation.\nA:H - Concurrent procfs traversal of tx_ops/rx_ops lists containing stale pointers to RCU-freed bcm_op objects can cause kernel oops/panic during list walking or field access, and UAF exploitation attempts can also crash the 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