CVE-2026-74605 (GCVE-0-2026-74605)
Vulnerability from cvelistv5
Published
2026-08-22 15:31
Modified
2026-08-25 05:40
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
eventfs: Use children field for rcu head and add memory barriers
When an eventfs inode is freed, it sets ei->is_freed and then uses its
ei->list to add it to the srcu link list as the list field is a union with
the rcu list head. As the ei->list is used to iterate over an SRCU
protected list without taking the eventfs_mutex, there's nothing stopping
the iteration over that list to see the ei->rcu instead of the ei->list
and it will read a corrupt target.
To fix this, change the union of the rcu list head with the children list.
On freeing the eventfs inode, set the is_free and execute a smp_wmb()
before adding the eventfs inode to the SRCU list.
On iteration of the ei->children list, at the start, execute a smp_rmb()
and then read the is_freed of the ei to see if the children list is still
valid. If is_freed is set, then the ei_child read is not valid and the
loop should exit immediately.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/tracefs/event_inode.c",
"fs/tracefs/internal.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "004f7232e49730448f91665e76bdd7dff8e0c638",
"status": "affected",
"version": "704f960dbee2f1634f4b4e16f208cb16eaf41c1e",
"versionType": "git"
},
{
"lessThan": "f0ece16ffca7384787b692431961ce202907acf5",
"status": "affected",
"version": "704f960dbee2f1634f4b4e16f208cb16eaf41c1e",
"versionType": "git"
},
{
"status": "affected",
"version": "f3f41f444b321ec393edbc251e024fd62658ce55",
"versionType": "git"
},
{
"status": "affected",
"version": "305c4e4d80aca2c2d9cf2ebdea56e2eca6d3a6aa",
"versionType": "git"
},
{
"lessThan": "6.7",
"status": "affected",
"version": "6.6.18",
"versionType": "semver"
},
{
"lessThan": "6.8",
"status": "affected",
"version": "6.7.6",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/tracefs/event_inode.c",
"fs/tracefs/internal.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"lessThan": "6.8",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"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": "7.1.9",
"versionStartIncluding": "6.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.6.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.7.6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\neventfs: Use children field for rcu head and add memory barriers\n\nWhen an eventfs inode is freed, it sets ei-\u003eis_freed and then uses its\nei-\u003elist to add it to the srcu link list as the list field is a union with\nthe rcu list head. As the ei-\u003elist is used to iterate over an SRCU\nprotected list without taking the eventfs_mutex, there\u0027s nothing stopping\nthe iteration over that list to see the ei-\u003ercu instead of the ei-\u003elist\nand it will read a corrupt target.\n\nTo fix this, change the union of the rcu list head with the children list.\nOn freeing the eventfs inode, set the is_free and execute a smp_wmb()\nbefore adding the eventfs inode to the SRCU list.\n\nOn iteration of the ei-\u003echildren list, at the start, execute a smp_rmb()\nand then read the is_freed of the ei to see if the children list is still\nvalid. If is_freed is set, then the ei_child read is not valid and the\nloop should exit immediately."
}
],
"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 - The bug is reached only via local syscalls (getdents64/readdir on tracefs eventfs directories through eventfs_iterate); tracefs is a kernel pseudo-filesystem under /sys/kernel/tracing with no network, adjacent-wireless, or physical-device entry path.\nAC:L - A single multithreaded attacker can loop getdents on events/ or events/kprobes/ while concurrently adding/removing kprobes via kprobe_events writes that call eventfs_remove_dir; the attacker controls both the SRCU list walk and the free path, making the race reliably triggerable.\nPR:L - Exploitation needs only local tracefs read/write access (getdents plus kprobe_events to create/remove eventfs children); kprobe_events checks only LOCKDOWN_TRACEFS and DAC with no capable(), and tracing-group gid mounts, Android/ChromeOS, and developer systems commonly grant this to unprivileged users.\nUI:N - The attacker performs all concurrent directory reads and dynamic event removals in their own process; no separate victim mount, click, or configuration action is required beyond tracefs already being accessible on the system.\nS:U - The union misuse causes kernel heap/list corruption and use-after-free within the tracing filesystem subsystem on the same host; it does not cross VM, container, IOMMU, or other security boundaries to affect a different authority.\nC:H - During list_for_each_entry_srcu over ei-\u003echildren, a concurrently freed child repurposes ei-\u003elist (union with rcu_head) for SRCU teardown, so the iterator follows corrupt list pointers and dereferences freed or attacker-influenced kernel memory typical of UAF read primitives.\nI:H - Corrupt SRCU list traversal over freed eventfs_inode objects is classic kernel UAF memory corruption that can be combined with heap grooming from repeated kprobe create/delete to obtain arbitrary kernel writes and local privilege escalation, not merely a bounded crash.\nA:H - Following a child\u0027s list.next after the list/rcu union is switched during free_ei() readily causes invalid pointer dereferences, kernel oops, or panic; the race can be retriggered at will by alternating getdents with dynamic event teardown."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-25T05:40:29.836Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/004f7232e49730448f91665e76bdd7dff8e0c638"
},
{
"url": "https://git.kernel.org/stable/c/f0ece16ffca7384787b692431961ce202907acf5"
}
],
"title": "eventfs: Use children field for rcu head and add memory barriers",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74605",
"datePublished": "2026-08-22T15:31:53.063Z",
"dateReserved": "2026-08-15T05:44:03.919Z",
"dateUpdated": "2026-08-25T05:40:29.836Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
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.
Loading…
Loading…