{"id":"CVE-2026-72116","state":"PUBLISHED","title":"can: bcm: fix stale rx/tx ops after device removal","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: fix stale rx/tx ops after device removal\n\nRX: an RX_SETUP update(!) for an existing op skipped can_rx_register()\nunconditionally, even when a concurrent NETDEV_UNREGISTER had already\ntorn down its registration (op->rx_reg_dev == NULL). This silently\ndid not re-enable frame delivery for that updated filter. bcm_rx_setup()\nnow re-registers in that case, while leaving rx_ops with ifindex = 0\n(all CAN devices) which never carry a tracked rx_reg_dev registered as-is.\n\nTX: bcm_notify() only handled bo->rx_ops on NETDEV_UNREGISTER, leaving\ntx_ops with an active cyclic transmission re-arming its hrtimer\nindefinitely to execute bcm_tx_timeout_handler(). Cancelling the hrtimer\nprevents the runaway timer and any injection into a later reused ifindex,\nsince nothing else calls bcm_can_tx() for the op until an explicit\nTX_SETUP update re-arms it.\n\nUnlike bcm_rx_unreg(), which clears the tracked rx_reg_dev for rx_ops,\nthe ifindex is intentionally left unchanged for tx_ops. bcm_tx_setup()\nalways rejects ifindex 0, so clearing it would strand the op: neither a\nlater TX_SETUP (bcm_find_op()) nor TX_DELETE (bcm_delete_tx_op()) could\never find it again, since both require an exact ifindex match.","publishedAt":"2026-08-15T05:52:56.260Z","updatedAt":"2026-10-16T18:44:56.837Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"d30a36066ed3abefb72ae18901f71841ba18b350","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"ca829677ffa2de5d79e06366e19ac1e4f5cc78dd","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"9517d8fb0b191398d35b9b7f8c719c1cc7761cb1","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"60d8a7942f4ed2d975207aaeba1adb576707e53d","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"f749e4564952d60e96930c09f2be99955d07c22e","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"6be3e1fedf03eab36a2c09d755d1171287b2014b","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"b31d0933509c5a35c0be5736a2ce8df0d1bf112c","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"3b762c0d950383ab7a002686c9136b9aa55d2d70","versionType":"git"}],"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":"2.6.25","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.25","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","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/d30a36066ed3abefb72ae18901f71841ba18b350","https://git.kernel.org/stable/c/ca829677ffa2de5d79e06366e19ac1e4f5cc78dd","https://git.kernel.org/stable/c/9517d8fb0b191398d35b9b7f8c719c1cc7761cb1","https://git.kernel.org/stable/c/60d8a7942f4ed2d975207aaeba1adb576707e53d","https://git.kernel.org/stable/c/f749e4564952d60e96930c09f2be99955d07c22e","https://git.kernel.org/stable/c/6be3e1fedf03eab36a2c09d755d1171287b2014b","https://git.kernel.org/stable/c/b31d0933509c5a35c0be5736a2ce8df0d1bf112c","https://git.kernel.org/stable/c/3b762c0d950383ab7a002686c9136b9aa55d2d70"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72116.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72116","state":"PUBLISHED","datePublished":"2026-08-15T05:52:56.260Z","dateUpdated":"2026-10-16T18:44:56.837Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.906Z"},"containers":{"cna":{"title":"can: bcm: fix stale rx/tx ops after device removal","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: fix stale rx/tx ops after device removal\n\nRX: an RX_SETUP update(!) for an existing op skipped can_rx_register()\nunconditionally, even when a concurrent NETDEV_UNREGISTER had already\ntorn down its registration (op->rx_reg_dev == NULL). This silently\ndid not re-enable frame delivery for that updated filter. bcm_rx_setup()\nnow re-registers in that case, while leaving rx_ops with ifindex = 0\n(all CAN devices) which never carry a tracked rx_reg_dev registered as-is.\n\nTX: bcm_notify() only handled bo->rx_ops on NETDEV_UNREGISTER, leaving\ntx_ops with an active cyclic transmission re-arming its hrtimer\nindefinitely to execute bcm_tx_timeout_handler(). Cancelling the hrtimer\nprevents the runaway timer and any injection into a later reused ifindex,\nsince nothing else calls bcm_can_tx() for the op until an explicit\nTX_SETUP update re-arms it.\n\nUnlike bcm_rx_unreg(), which clears the tracked rx_reg_dev for rx_ops,\nthe ifindex is intentionally left unchanged for tx_ops. bcm_tx_setup()\nalways rejects ifindex 0, so clearing it would strand the op: neither a\nlater TX_SETUP (bcm_find_op()) nor TX_DELETE (bcm_delete_tx_op()) could\never find it again, since both require an exact ifindex match."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"d30a36066ed3abefb72ae18901f71841ba18b350","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"ca829677ffa2de5d79e06366e19ac1e4f5cc78dd","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"9517d8fb0b191398d35b9b7f8c719c1cc7761cb1","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"60d8a7942f4ed2d975207aaeba1adb576707e53d","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"f749e4564952d60e96930c09f2be99955d07c22e","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"6be3e1fedf03eab36a2c09d755d1171287b2014b","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"b31d0933509c5a35c0be5736a2ce8df0d1bf112c","versionType":"git"},{"version":"ffd980f976e7fd666c2e61bf8ab35107efd11828","status":"affected","lessThan":"3b762c0d950383ab7a002686c9136b9aa55d2d70","versionType":"git"}],"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":"2.6.25","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.25","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","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/d30a36066ed3abefb72ae18901f71841ba18b350"},{"url":"https://git.kernel.org/stable/c/ca829677ffa2de5d79e06366e19ac1e4f5cc78dd"},{"url":"https://git.kernel.org/stable/c/9517d8fb0b191398d35b9b7f8c719c1cc7761cb1"},{"url":"https://git.kernel.org/stable/c/60d8a7942f4ed2d975207aaeba1adb576707e53d"},{"url":"https://git.kernel.org/stable/c/f749e4564952d60e96930c09f2be99955d07c22e"},{"url":"https://git.kernel.org/stable/c/6be3e1fedf03eab36a2c09d755d1171287b2014b"},{"url":"https://git.kernel.org/stable/c/b31d0933509c5a35c0be5736a2ce8df0d1bf112c"},{"url":"https://git.kernel.org/stable/c/3b762c0d950383ab7a002686c9136b9aa55d2d70"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only via local PF_CAN/CAN_BCM syscalls (socket/connect/sendmsg TX_SETUP or RX_SETUP); bcm_tx_timeout_handler() is driven by a local hrtimer, not by remote network services or CAN bus frames alone.\nAC:L - An attacker controls both sides by arming cyclic TX with SETTIMER/STARTTIMER, then triggering or waiting for NETDEV_UNREGISTER (e.g., concurrent ip link del in a user namespace) while ifindex reuse is normal kernel behavior, making injection reliably achievable.\nPR:L - can_create(), bcm_connect(), and bcm_sendmsg() perform no capability checks; any local user with CAN access (or CAP_NET_ADMIN in an unprivileged user namespace to create vcan) can open BCM sockets and program cyclic TX/RX ops.\nUI:N - Exploitation requires only the attacker opening a BCM socket and sending TX_SETUP/RX_SETUP messages; no victim action such as mounting media or opening files is needed once local CAN access exists.\nS:U - Impact is unauthorized CAN transmission/monitoring disruption within the same kernel host; it does not cross VM, container, or IOMMU security boundaries even when frames reach an adjacent vehicle or factory CAN segment.\nC:N - The flaw causes stale timer-driven transmission and missed RX re-registration, not kernel memory disclosure; no out-of-bounds read, UAF, or other information-leak primitive is present in this bug.\nI:H - After NETDEV_UNREGISTER, orphaned tx_ops keep bcm_can_tx() running with a stale ifindex, so attacker-crafted cyclic CAN frames can be injected onto any later netdev that reuses that ifindex, including safety-critical automotive or industrial buses.\nA:H - Uncancelled hrtimers on stale tx_ops re-arm bcm_tx_timeout_handler() indefinitely after device removal, causing persistent timer/softirq CPU consumption, and the RX_SETUP path can silently stop frame delivery after unregister races."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:36:05.976Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72116","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T18:41:52.725992Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:44:56.837Z"}}]}}}