CVE-2026-72116 (GCVE-0-2026-72116)
Vulnerability from cvelistv5
Published
2026-08-15 05:52
Modified
2026-08-19 16:36
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
can: bcm: fix stale rx/tx ops after device removal
RX: an RX_SETUP update(!) for an existing op skipped can_rx_register()
unconditionally, even when a concurrent NETDEV_UNREGISTER had already
torn down its registration (op->rx_reg_dev == NULL). This silently
did not re-enable frame delivery for that updated filter. bcm_rx_setup()
now re-registers in that case, while leaving rx_ops with ifindex = 0
(all CAN devices) which never carry a tracked rx_reg_dev registered as-is.
TX: bcm_notify() only handled bo->rx_ops on NETDEV_UNREGISTER, leaving
tx_ops with an active cyclic transmission re-arming its hrtimer
indefinitely to execute bcm_tx_timeout_handler(). Cancelling the hrtimer
prevents the runaway timer and any injection into a later reused ifindex,
since nothing else calls bcm_can_tx() for the op until an explicit
TX_SETUP update re-arms it.
Unlike bcm_rx_unreg(), which clears the tracked rx_reg_dev for rx_ops,
the ifindex is intentionally left unchanged for tx_ops. bcm_tx_setup()
always rejects ifindex 0, so clearing it would strand the op: neither a
later TX_SETUP (bcm_find_op()) nor TX_DELETE (bcm_delete_tx_op()) could
ever find it again, since both require an exact ifindex match.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 Version: ffd980f976e7fd666c2e61bf8ab35107efd11828 |
||
{
"containers": {
"cna": {
"affected": [
{
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"product": "Linux",
"programFiles": [
"net/can/bcm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
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"programFiles": [
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],
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"vendor": "Linux",
"versions": [
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"version": "2.6.25"
},
{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
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}
],
"negate": false,
"operator": "OR"
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],
"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-\u003erx_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-\u003erx_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": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
"version": "3.1"
},
"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": {
"dateUpdated": "2026-08-19T16:36:05.976Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72116",
"datePublished": "2026-08-15T05:52:56.260Z",
"dateReserved": "2026-08-09T03:40:39.906Z",
"dateUpdated": "2026-08-19T16:36:05.976Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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