CVE-2026-72123

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72123", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.907Z", "datePublished": "2026-08-15T05:53:01.433Z", "dateUpdated": "2026-10-16T18:44:57.598Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:36:18.988Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF\n\nCommit f1b4e32aca08 (\"can: bcm: use call_rcu() instead of costly\nsynchronize_rcu()\") replaced synchronize_rcu() in bcm_delete_rx_op()\nwith call_rcu() and introduced the RX_NO_AUTOTIMER flag.\n\nHowever, this flag check was omitted for thrtimer in the packet rx\nfast-path. During BCM RX operation teardown, a concurrent RCU reader\n(bcm_rx_handler) can race and re-arm thrtimer via\nbcm_rx_update_and_send() after call_rcu() has been scheduled. Once\nthe RCU grace period elapses, bcm_op is freed. The subsequently\nfiring thrtimer then dereferences the deallocated op, causing a UAF.\n\nAdding flag checks to the rx fast-path (bcm_rx_update_and_send) does not\nfully close the TOCTOU race and introduces latency for every CAN frame.\nConversely, calling hrtimer_cancel() directly inside the RCU callback\n(softirq context) is fatal as hrtimer_cancel() can sleep, triggering\na \"scheduling while atomic\" panic.\n\nResolve this by deferring the timer cancellation and memory free to a\ndedicated unbound workqueue (bcm_wq). The RCU callback now queues a\nwork item to bcm_wq, which safely cancels both timers and deallocates\nmemory in sleepable process context. A dedicated workqueue is used to\nprevent system-wide WQ saturation and is cleanly flushed/destroyed\non module unload to avoid rmmod page faults.\n\nSince the deferred work can now outlive the calling context by an\nunbounded amount, also take a reference on op->sk when it is assigned\nand drop it only once the deferred work has cancelled both timers, so a\nsocket can no longer be freed out from under a still-armed timer whose\ncallback (bcm_send_to_user()) dereferences op->sk."}], "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 BCM socket syscalls (sendmsg with RX_SETUP/SETTIMER/ival2 throttling and RX_DELETE); CAN frames can be injected locally via loopback without physical bus access.\nAC:L - The attacker controls both sides of the race by concurrently issuing RX_DELETE teardown and delivering matching CAN frames (e.g., via threads or paired BCM/RAW sockets), making the thrtimer re-arm UAF reliably triggerable.\nPR:L - No kernel capability check gates AF_CAN/CAN_BCM socket creation or bcm_sendmsg opcodes; any unprivileged local user with socket access (including via user namespaces with vcan) can reach the vulnerable path.\nUI:N - No victim interaction is required; the attacker self-triggers the race through their own BCM socket operations and locally injected CAN traffic.\nS:U - Impact is confined to kernel memory corruption and local privilege escalation within the same kernel security boundary, not a cross-boundary escape such as VM or IOMMU bypass.\nC:H - The thrtimer UAF dereferences freed bcm_op fields (locks, frame buffers, op->sk) in bcm_rx_thr_handler/bcm_send_to_user, enabling attacker-controlled heap reuse and arbitrary kernel memory disclosure.\nI:H - UAF on the bcm_op slab object allows heap spraying to corrupt function pointers, timers, and sock structures, providing a standard path to arbitrary kernel writes and local privilege escalation.\nA:H - The freed-op dereference in the hrtimer softirq path causes kernel oops/panic under normal exploitation attempts, and successful memory corruption can crash or hang the system."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/can/bcm.c"], "versions": [{"version": "85cd41070df992d3c0dfd828866fdd243d3b774a", "lessThan": "de5fce46637de05bef56ec08528127676eb6fc9b", "status": "affected", "versionType": "git"}, {"version": "f34f2a18e47b73e48f90a757e1f4aaa8c7d665a1", "lessThan": "036a8c320ca11bc912e8027adcfad14b326f067e", "status": "affected", "versionType": "git"}, {"version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "3cf4fd5316f449811d8baf1bc6978ef5a7b743a9", "status": "affected", "versionType": "git"}, {"version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "4177762f70646ac48a2af382e45a795cbd295198", "status": "affected", "versionType": "git"}, {"version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f", "status": "affected", "versionType": "git"}, {"version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5", "status": "affected", "versionType": "git"}, {"version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "ce2d4b121fb7545e1ed588e860c8e5fd5ad45224", "status": "affected", "versionType": "git"}, {"version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "68973f9db76144825e4f35dfdc80fb8279eb2d57", "status": "affected", "versionType": "git"}, {"version": "fbac09a3b8890003c0c55294c00709f3ae5501bb", "status": "affected", "versionType": "git"}, {"version": "5b48f5711f1c630841ab78dcc061de902f0e37bf", "status": "affected", "versionType": "git"}, {"version": "edb4baffb9483141a50fb7f7146cfe4a4c0c2db8", "status": "affected", "versionType": "git"}, {"version": "5.10.130", "lessThan": "5.10.265", "status": "affected", "versionType": "semver"}, {"version": "5.15.54", "lessThan": "5.15.216", "status": "affected", "versionType": "semver"}, {"version": "4.19.252", "lessThan": "4.20", "status": "affected", "versionType": "semver"}, {"version": "5.4.205", "lessThan": "5.5", "status": "affected", "versionType": "semver"}, {"version": "5.18.11", "lessThan": "5.19", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/can/bcm.c"], "versions": [{"version": "5.19", "status": "affected"}, {"version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.130", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.54", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.1.178"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.252"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.205"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18.11"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/de5fce46637de05bef56ec08528127676eb6fc9b"}, {"url": "https://git.kernel.org/stable/c/036a8c320ca11bc912e8027adcfad14b326f067e"}, {"url": "https://git.kernel.org/stable/c/3cf4fd5316f449811d8baf1bc6978ef5a7b743a9"}, {"url": "https://git.kernel.org/stable/c/4177762f70646ac48a2af382e45a795cbd295198"}, {"url": "https://git.kernel.org/stable/c/6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f"}, {"url": "https://git.kernel.org/stable/c/cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5"}, {"url": "https://git.kernel.org/stable/c/ce2d4b121fb7545e1ed588e860c8e5fd5ad45224"}, {"url": "https://git.kernel.org/stable/c/68973f9db76144825e4f35dfdc80fb8279eb2d57"}], "title": "can: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-72123", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T18:42:12.952847Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T18:44:57.598Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-72123", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T18:42:12.952847Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T18:42:13.587Z"}}], "cna": {"title": "can: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.8, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - Exploitation requires local BCM socket syscalls (sendmsg with RX_SETUP/SETTIMER/ival2 throttling and RX_DELETE); CAN frames can be injected locally via loopback without physical bus access.\nAC:L - The attacker controls both sides of the race by concurrently issuing RX_DELETE teardown and delivering matching CAN frames (e.g., via threads or paired BCM/RAW sockets), making the thrtimer re-arm UAF reliably triggerable.\nPR:L - No kernel capability check gates AF_CAN/CAN_BCM socket creation or bcm_sendmsg opcodes; any unprivileged local user with socket access (including via user namespaces with vcan) can reach the vulnerable path.\nUI:N - No victim interaction is required; the attacker self-triggers the race through their own BCM socket operations and locally injected CAN traffic.\nS:U - Impact is confined to kernel memory corruption and local privilege escalation within the same kernel security boundary, not a cross-boundary escape such as VM or IOMMU bypass.\nC:H - The thrtimer UAF dereferences freed bcm_op fields (locks, frame buffers, op->sk) in bcm_rx_thr_handler/bcm_send_to_user, enabling attacker-controlled heap reuse and arbitrary kernel memory disclosure.\nI:H - UAF on the bcm_op slab object allows heap spraying to corrupt function pointers, timers, and sock structures, providing a standard path to arbitrary kernel writes and local privilege escalation.\nA:H - The freed-op dereference in the hrtimer softirq path causes kernel oops/panic under normal exploitation attempts, and successful memory corruption can crash or hang the system."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "85cd41070df992d3c0dfd828866fdd243d3b774a", "lessThan": "de5fce46637de05bef56ec08528127676eb6fc9b", "versionType": "git"}, {"status": "affected", "version": "f34f2a18e47b73e48f90a757e1f4aaa8c7d665a1", "lessThan": "036a8c320ca11bc912e8027adcfad14b326f067e", "versionType": "git"}, {"status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "3cf4fd5316f449811d8baf1bc6978ef5a7b743a9", "versionType": "git"}, {"status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "4177762f70646ac48a2af382e45a795cbd295198", "versionType": "git"}, {"status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f", "versionType": "git"}, {"status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5", "versionType": "git"}, {"status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "ce2d4b121fb7545e1ed588e860c8e5fd5ad45224", "versionType": "git"}, {"status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "lessThan": "68973f9db76144825e4f35dfdc80fb8279eb2d57", "versionType": "git"}, {"status": "affected", "version": "fbac09a3b8890003c0c55294c00709f3ae5501bb", "versionType": "git"}, {"status": "affected", "version": "5b48f5711f1c630841ab78dcc061de902f0e37bf", "versionType": "git"}, {"status": "affected", "version": "edb4baffb9483141a50fb7f7146cfe4a4c0c2db8", "versionType": "git"}, {"status": "affected", "version": "5.10.130", "lessThan": "5.10.265", "versionType": "semver"}, {"status": "affected", "version": "5.15.54", "lessThan": "5.15.216", "versionType": "semver"}, {"status": "affected", "version": "4.19.252", "lessThan": "4.20", "versionType": "semver"}, {"status": "affected", "version": "5.4.205", "lessThan": "5.5", "versionType": "semver"}, {"status": "affected", "version": "5.18.11", "lessThan": "5.19", "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": "5.19"}, {"status": "unaffected", "version": "0", "lessThan": "5.19", "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": "6.1.178", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.145", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.97", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.40", "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"}], "references": [{"url": "https://git.kernel.org/stable/c/de5fce46637de05bef56ec08528127676eb6fc9b"}, {"url": "https://git.kernel.org/stable/c/036a8c320ca11bc912e8027adcfad14b326f067e"}, {"url": "https://git.kernel.org/stable/c/3cf4fd5316f449811d8baf1bc6978ef5a7b743a9"}, {"url": "https://git.kernel.org/stable/c/4177762f70646ac48a2af382e45a795cbd295198"}, {"url": "https://git.kernel.org/stable/c/6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f"}, {"url": "https://git.kernel.org/stable/c/cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5"}, {"url": "https://git.kernel.org/stable/c/ce2d4b121fb7545e1ed588e860c8e5fd5ad45224"}, {"url": "https://git.kernel.org/stable/c/68973f9db76144825e4f35dfdc80fb8279eb2d57"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF\n\nCommit f1b4e32aca08 (\"can: bcm: use call_rcu() instead of costly\nsynchronize_rcu()\") replaced synchronize_rcu() in bcm_delete_rx_op()\nwith call_rcu() and introduced the RX_NO_AUTOTIMER flag.\n\nHowever, this flag check was omitted for thrtimer in the packet rx\nfast-path. During BCM RX operation teardown, a concurrent RCU reader\n(bcm_rx_handler) can race and re-arm thrtimer via\nbcm_rx_update_and_send() after call_rcu() has been scheduled. Once\nthe RCU grace period elapses, bcm_op is freed. The subsequently\nfiring thrtimer then dereferences the deallocated op, causing a UAF.\n\nAdding flag checks to the rx fast-path (bcm_rx_update_and_send) does not\nfully close the TOCTOU race and introduces latency for every CAN frame.\nConversely, calling hrtimer_cancel() directly inside the RCU callback\n(softirq context) is fatal as hrtimer_cancel() can sleep, triggering\na \"scheduling while atomic\" panic.\n\nResolve this by deferring the timer cancellation and memory free to a\ndedicated unbound workqueue (bcm_wq). The RCU callback now queues a\nwork item to bcm_wq, which safely cancels both timers and deallocates\nmemory in sleepable process context. A dedicated workqueue is used to\nprevent system-wide WQ saturation and is cleanly flushed/destroyed\non module unload to avoid rmmod page faults.\n\nSince the deferred work can now outlive the calling context by an\nunbounded amount, also take a reference on op->sk when it is assigned\nand drop it only once the deferred work has cancelled both timers, so a\nsocket can no longer be freed out from under a still-armed timer whose\ncallback (bcm_send_to_user()) dereferences op->sk."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.265", "versionStartIncluding": "5.10.130"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.216", "versionStartIncluding": "5.15.54"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.178", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.145", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.97", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.40", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.5", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "4.19.252"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "5.4.205"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "5.18.11"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:36:18.988Z"}}}, "cveMetadata": {"cveId": "CVE-2026-72123", "state": "PUBLISHED", "dateUpdated": "2026-10-16T18:44:57.598Z", "dateReserved": "2026-08-09T03:40:39.907Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-15T05:53:01.433Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/can/bcm.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "de5fce46637de05bef56ec08528127676eb6fc9b", "status": "affected", "version": "85cd41070df992d3c0dfd828866fdd243d3b774a", "versionType": "git"}, {"lessThan": "036a8c320ca11bc912e8027adcfad14b326f067e", "status": "affected", "version": "f34f2a18e47b73e48f90a757e1f4aaa8c7d665a1", "versionType": "git"}, {"lessThan": "3cf4fd5316f449811d8baf1bc6978ef5a7b743a9", "status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "versionType": "git"}, {"lessThan": "4177762f70646ac48a2af382e45a795cbd295198", "status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "versionType": "git"}, {"lessThan": "6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f", "status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "versionType": "git"}, {"lessThan": "cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5", "status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "versionType": "git"}, {"lessThan": "ce2d4b121fb7545e1ed588e860c8e5fd5ad45224", "status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "versionType": "git"}, {"lessThan": "68973f9db76144825e4f35dfdc80fb8279eb2d57", "status": "affected", "version": "f1b4e32aca0811aa011c76e5d6cf2fa19224b386", "versionType": "git"}, {"status": "affected", "version": "fbac09a3b8890003c0c55294c00709f3ae5501bb", "versionType": "git"}, {"status": "affected", "version": "5b48f5711f1c630841ab78dcc061de902f0e37bf", "versionType": "git"}, {"status": "affected", "version": "edb4baffb9483141a50fb7f7146cfe4a4c0c2db8", "versionType": "git"}, {"lessThan": "5.10.265", "status": "affected", "version": "5.10.130", "versionType": "semver"}, {"lessThan": "5.15.216", "status": "affected", "version": "5.15.54", "versionType": "semver"}, {"lessThan": "4.20", "status": "affected", "version": "4.19.252", "versionType": "semver"}, {"lessThan": "5.5", "status": "affected", "version": "5.4.205", "versionType": "semver"}, {"lessThan": "5.19", "status": "affected", "version": "5.18.11", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/can/bcm.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.19"}, {"lessThan": "5.19", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.178", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF\n\nCommit f1b4e32aca08 (\"can: bcm: use call_rcu() instead of costly\nsynchronize_rcu()\") replaced synchronize_rcu() in bcm_delete_rx_op()\nwith call_rcu() and introduced the RX_NO_AUTOTIMER flag.\n\nHowever, this flag check was omitted for thrtimer in the packet rx\nfast-path. During BCM RX operation teardown, a concurrent RCU reader\n(bcm_rx_handler) can race and re-arm thrtimer via\nbcm_rx_update_and_send() after call_rcu() has been scheduled. Once\nthe RCU grace period elapses, bcm_op is freed. The subsequently\nfiring thrtimer then dereferences the deallocated op, causing a UAF.\n\nAdding flag checks to the rx fast-path (bcm_rx_update_and_send) does not\nfully close the TOCTOU race and introduces latency for every CAN frame.\nConversely, calling hrtimer_cancel() directly inside the RCU callback\n(softirq context) is fatal as hrtimer_cancel() can sleep, triggering\na \"scheduling while atomic\" panic.\n\nResolve this by deferring the timer cancellation and memory free to a\ndedicated unbound workqueue (bcm_wq). The RCU callback now queues a\nwork item to bcm_wq, which safely cancels both timers and deallocates\nmemory in sleepable process context. A dedicated workqueue is used to\nprevent system-wide WQ saturation and is cleanly flushed/destroyed\non module unload to avoid rmmod page faults.\n\nSince the deferred work can now outlive the calling context by an\nunbounded amount, also take a reference on op->sk when it is assigned\nand drop it only once the deferred work has cancelled both timers, so a\nsocket can no longer be freed out from under a still-armed timer whose\ncallback (bcm_send_to_user()) dereferences op->sk."}], "id": "CVE-2026-72123", "lastModified": "2026-10-16T19:17:10.177", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-72123", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T18:42:12.952847Z", "version": "2.0.3"}}]}, "published": "2026-08-15T06:21:29.577", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/036a8c320ca11bc912e8027adcfad14b326f067e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3cf4fd5316f449811d8baf1bc6978ef5a7b743a9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4177762f70646ac48a2af382e45a795cbd295198"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/68973f9db76144825e4f35dfdc80fb8279eb2d57"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ce2d4b121fb7545e1ed588e860c8e5fd5ad45224"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/de5fce46637de05bef56ec08528127676eb6fc9b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: can: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF", "id": "2516344", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516344"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-364", "details": ["A flaw was found in the Linux kernel's Controller Area Network (CAN) Broadcom (BCM) driver. A race condition during the BCM RX operation teardown can lead to a Use-After-Free (UAF) vulnerability. This occurs when a timer attempts to access memory that has already been deallocated, potentially causing a system panic and resulting in a Denial of Service (DoS)."], "name": "CVE-2026-72123", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72123\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72123\nhttps://lore.kernel.org/linux-cve-announce/2026081529-CVE-2026-72123-bf75@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1b4e32aca0811aa011c76e5d6cf2fa19224b386,3cf4fd5316f449811d8baf1bc6978ef5a7b743a9)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1b4e32aca0811aa011c76e5d6cf2fa19224b386,4177762f70646ac48a2af382e45a795cbd295198)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1b4e32aca0811aa011c76e5d6cf2fa19224b386,6fd08e8d826c3aa4cc7021f5f9cdbb7fa7441d3f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1b4e32aca0811aa011c76e5d6cf2fa19224b386,cd830e0bc25ee2d38cbfbdbb3cd77c5f53b2b6d5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1b4e32aca0811aa011c76e5d6cf2fa19224b386,ce2d4b121fb7545e1ed588e860c8e5fd5ad45224)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1b4e32aca0811aa011c76e5d6cf2fa19224b386,68973f9db76144825e4f35dfdc80fb8279eb2d57)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "fbac09a3b8890003c0c55294c00709f3ae5501bb"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "5b48f5711f1c630841ab78dcc061de902f0e37bf"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "85cd41070df992d3c0dfd828866fdd243d3b774a"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "f34f2a18e47b73e48f90a757e1f4aaa8c7d665a1"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "edb4baffb9483141a50fb7f7146cfe4a4c0c2db8"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.19.252,4.20)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.4.205,5.5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.10.130,5.11)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.15.54,5.16)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.18.11,5.19)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "5.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.178,6.2.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.145,6.7.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.97,6.13.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.40,6.19.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T09:00:06.792250+00:00", "updated": "2026-08-18T03:00:09.709368+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}