{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72116", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.906Z", "datePublished": "2026-08-15T05:52:56.260Z", "dateUpdated": "2026-08-19T16:36:05.976Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:36:05.976Z" }, "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." } ], "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." } ] } ], "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": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "d30a36066ed3abefb72ae18901f71841ba18b350", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "ca829677ffa2de5d79e06366e19ac1e4f5cc78dd", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "9517d8fb0b191398d35b9b7f8c719c1cc7761cb1", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "60d8a7942f4ed2d975207aaeba1adb576707e53d", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "f749e4564952d60e96930c09f2be99955d07c22e", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "6be3e1fedf03eab36a2c09d755d1171287b2014b", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "b31d0933509c5a35c0be5736a2ce8df0d1bf112c", "status": "affected", "versionType": "git" }, { "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828", "lessThan": "3b762c0d950383ab7a002686c9136b9aa55d2d70", "status": "affected", "versionType": "git" } ] }, { "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": "2.6.25", "status": "affected" }, { "version": "0", "lessThan": "2.6.25", "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": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "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": "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" } ] } ] } ], "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" } ], "title": "can: bcm: fix stale rx/tx ops after device removal", "x_generator": { "engine": "bippy-1.2.0" } } } }