CVE-2026-72042 (GCVE-0-2026-72042)
Vulnerability from cvelistv5
Published
2026-08-15 05:52
Modified
2026-08-17 05:39
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ipmi: Fix user refcount underflow in event delivery
ipmi_alloc_recv_msg(user) takes the temporary user reference owned by the
receive message, and ipmi_free_recv_msg() drops it again. If event delivery
fails after allocating receive messages for earlier users,
handle_read_event_rsp() rolls those messages back with
ipmi_free_recv_msg().
That rollback path still drops user->refcount explicitly after freeing each
message. The extra put can free a user that remains linked on intf->users,
so later event delivery may dereference a freed user or trip refcount_t's
addition-on-zero warning when ipmi_alloc_recv_msg() tries to acquire
another reference.
Remove the stale explicit put and the now-dead user assignment. Keep the
list_del() and ipmi_free_recv_msg() calls; they are the required rollback
operations.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: b52da4054ee0bf9ecb44996f2c83236ff50b3812 Version: b52da4054ee0bf9ecb44996f2c83236ff50b3812 Version: b52da4054ee0bf9ecb44996f2c83236ff50b3812 Version: f63723ca7d7623f9dae1990973cd158671f03c56 Version: 348121b29594d42d1635648fd3ed31dfa25351d5 Version: 53d6e403affbf6df2c859a0ea00ccfc1e72090ca Version: 0ed73be9a2547ffb9b5c1d879ad9bfab73d920b5 Version: 6.1.157 ≤ Version: 6.6.113 ≤ Version: 6.12.54 ≤ Version: 6.17.4 ≤ |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/char/ipmi/ipmi_msghandler.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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},
{
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"status": "affected",
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"versionType": "git"
},
{
"lessThan": "6aa9e61c46465d231e9beddf56af7effd71be682",
"status": "affected",
"version": "b52da4054ee0bf9ecb44996f2c83236ff50b3812",
"versionType": "git"
},
{
"status": "affected",
"version": "f63723ca7d7623f9dae1990973cd158671f03c56",
"versionType": "git"
},
{
"status": "affected",
"version": "348121b29594d42d1635648fd3ed31dfa25351d5",
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},
{
"status": "affected",
"version": "53d6e403affbf6df2c859a0ea00ccfc1e72090ca",
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{
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"version": "0ed73be9a2547ffb9b5c1d879ad9bfab73d920b5",
"versionType": "git"
},
{
"lessThan": "6.2",
"status": "affected",
"version": "6.1.157",
"versionType": "semver"
},
{
"lessThan": "6.7",
"status": "affected",
"version": "6.6.113",
"versionType": "semver"
},
{
"lessThan": "6.13",
"status": "affected",
"version": "6.12.54",
"versionType": "semver"
},
{
"lessThan": "6.18",
"status": "affected",
"version": "6.17.4",
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]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/char/ipmi/ipmi_msghandler.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"lessThan": "6.18",
"status": "unaffected",
"version": "0",
"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"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "6.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "6.18",
"vulnerable": true
},
{
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},
{
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"versionStartIncluding": "6.1.157",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.6.113",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.12.54",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.17.4",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipmi: Fix user refcount underflow in event delivery\n\nipmi_alloc_recv_msg(user) takes the temporary user reference owned by the\nreceive message, and ipmi_free_recv_msg() drops it again. If event delivery\nfails after allocating receive messages for earlier users,\nhandle_read_event_rsp() rolls those messages back with\nipmi_free_recv_msg().\n\nThat rollback path still drops user-\u003erefcount explicitly after freeing each\nmessage. The extra put can free a user that remains linked on intf-\u003eusers,\nso later event delivery may dereference a freed user or trip refcount_t\u0027s\naddition-on-zero warning when ipmi_alloc_recv_msg() tries to acquire\nanother reference.\n\nRemove the stale explicit put and the now-dead user assignment. Keep the\nlist_del() and ipmi_free_recv_msg() calls; they are the required rollback\noperations."
}
],
"metrics": [
{
"cvssV3_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",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Exploitation requires local setup via /dev/ipmiN (open, IPMICTL_SET_GETS_EVENTS, message flooding); the refcount bug is in handle_read_event_rsp() during host-side BMC event processing, not via a remote packet path to the kernel.\nAC:L - An attacker with IPMI device access controls both sides: multiple fds, gets_events registration, filling one user\u0027s outstanding-message limit to force EBUSY, and generating/waiting for BMC events via their own IPMI commands.\nPR:L - ipmi_open/ipmi_create_user perform no capability() check; access is gated only by /dev/ipmiN DAC, and BMC-equipped servers often grant that node to a non-root management group (ipmi) for ipmitool/freeipmi.\nUI:N - No victim interaction is required; the attacker drives all setup and triggering through their own IPMI file descriptors and ioctls.\nS:U - This is a host-kernel heap use-after-free of struct ipmi_user within the same OS security authority, with no VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:H - Premature free_ipmi_user() leaves a dangling ipmi_user on intf-\u003eusers; later iterations call kref_get and read handler pointers from freed slab memory, yielding arbitrary kernel read primitives per UAF guidance.\nI:H - Freed ipmi_user objects contain function pointers (handler-\u003eipmi_recv_hndl); smi_work later invokes these on reclaimed memory, enabling heap spray and control-flow hijack for arbitrary kernel write/code execution.\nA:H - The extra kref_put causes refcount underflow warnings and use-after-free of ipmi_user; subsequent event delivery dereferences freed memory and readily triggers kernel oops/panic under KASAN/poisoning."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:39:41.572Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/ddbb6e3dc9bb4743de686aa1598c31e745cee76b"
},
{
"url": "https://git.kernel.org/stable/c/7be349d4fcc5e065295b83418a22d27a68afbdb6"
},
{
"url": "https://git.kernel.org/stable/c/6aa9e61c46465d231e9beddf56af7effd71be682"
}
],
"title": "ipmi: Fix user refcount underflow in event delivery",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72042",
"datePublished": "2026-08-15T05:52:01.454Z",
"dateReserved": "2026-08-09T03:40:39.902Z",
"dateUpdated": "2026-08-17T05:39:41.572Z",
"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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