FKIE_CVE-2026-63814
Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-07-20 15:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
f2fs: validate ACL entry sizes in f2fs_acl_from_disk()
f2fs_acl_count() only validates the aggregate ACL xattr length. A
malformed ACL can still place ACL_USER or ACL_GROUP in a slot that only
contains struct f2fs_acl_entry_short bytes, and f2fs_acl_from_disk()
then reads entry->e_id before verifying that a full entry fits.
Require a short entry before reading e_tag and e_perm, and require a
full entry before reading e_id for ACL_USER and ACL_GROUP. Return
-EFSCORRUPTED from these new truncated-entry checks, while keeping the
pre-existing -EINVAL paths unchanged.
Validation reproduced this kernel report:
KASAN slab-out-of-bounds in __f2fs_get_acl+0x6fb/0x7e0
RIP: 0033:0x7f4b835ea7aa
The buggy address belongs to the object at ffff888114589960 which belongs
to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of allocated 8-byte
region [ffff888114589960, ffff888114589968)
Read of size 4
Call trace:
dump_stack_lvl+0x66/0xa0 (?:?)
print_report+0xce/0x630 (?:?)
__f2fs_get_acl+0x6fb/0x7e0 (fs/f2fs/acl.c:169)
srso_alias_return_thunk+0x5/0xfbef5 (?:?)
__virt_addr_valid+0x224/0x430 (?:?)
kasan_report+0xe0/0x110 (?:?)
__f2fs_get_acl+0x5/0x7e0 (fs/f2fs/acl.c:169)
__get_acl+0x281/0x380 (?:?)
vfs_get_acl+0x10b/0x190 (?:?)
do_get_acl+0x2a/0x410 (?:?)
do_get_acl+0x9/0x410 (?:?)
do_getxattr+0xe8/0x260 (?:?)
filename_getxattr+0xd1/0x140 (?:?)
do_getname+0x2d/0x2d0 (?:?)
path_getxattrat+0x16c/0x200 (?:?)
lock_release+0xc8/0x290 (?:?)
cgroup_update_frozen+0x9d/0x320 (?:?)
lockdep_hardirqs_on_prepare+0xea/0x1a0 (?:?)
trace_hardirqs_on+0x1a/0x170 (?:?)
_raw_spin_unlock_irq+0x28/0x50 (?:?)
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/f2fs/acl.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "733cd8474e6d763d75ed96f3f2b98a25480cf2b9",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "4e2a96ec7236e248e706850568e0a925fd21b588",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "442ca20c54038e2400cf28aaa944cf1de2c8e65d",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "1ddf3fd21c4c652f9cab5552515c04a166662306",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "aba4f94ac1832c7299c33e1b4fe5f87eef6dc8f1",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "ff83de56882cb8466184d322abece2589258ca56",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "5d8a39649947a4e86c8fbc682d7fc0041b8d109a",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
},
{
"lessThan": "c4810ada31e80cbe4011467c4f3b1e93f94134f3",
"status": "affected",
"version": "af48b85b8cd3fbb12c9b6759c16db6d69c0b03da",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/f2fs/acl.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.8"
},
{
"lessThan": "3.8",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.260",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.211",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.177",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.144",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.95",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.38",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2-rc1",
"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\nf2fs: validate ACL entry sizes in f2fs_acl_from_disk()\n\nf2fs_acl_count() only validates the aggregate ACL xattr length. A\nmalformed ACL can still place ACL_USER or ACL_GROUP in a slot that only\ncontains struct f2fs_acl_entry_short bytes, and f2fs_acl_from_disk()\nthen reads entry-\u003ee_id before verifying that a full entry fits.\n\nRequire a short entry before reading e_tag and e_perm, and require a\nfull entry before reading e_id for ACL_USER and ACL_GROUP. Return\n-EFSCORRUPTED from these new truncated-entry checks, while keeping the\npre-existing -EINVAL paths unchanged.\n\nValidation reproduced this kernel report:\nKASAN slab-out-of-bounds in __f2fs_get_acl+0x6fb/0x7e0\nRIP: 0033:0x7f4b835ea7aa\nThe buggy address belongs to the object at ffff888114589960 which belongs\nto the cache kmalloc-8 of size 8\nThe buggy address is located 0 bytes to the right of allocated 8-byte\nregion [ffff888114589960, ffff888114589968)\nRead of size 4\nCall trace:\n dump_stack_lvl+0x66/0xa0 (?:?)\n print_report+0xce/0x630 (?:?)\n __f2fs_get_acl+0x6fb/0x7e0 (fs/f2fs/acl.c:169)\n srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n __virt_addr_valid+0x224/0x430 (?:?)\n kasan_report+0xe0/0x110 (?:?)\n __f2fs_get_acl+0x5/0x7e0 (fs/f2fs/acl.c:169)\n __get_acl+0x281/0x380 (?:?)\n vfs_get_acl+0x10b/0x190 (?:?)\n do_get_acl+0x2a/0x410 (?:?)\n do_get_acl+0x9/0x410 (?:?)\n do_getxattr+0xe8/0x260 (?:?)\n filename_getxattr+0xd1/0x140 (?:?)\n do_getname+0x2d/0x2d0 (?:?)\n path_getxattrat+0x16c/0x200 (?:?)\n lock_release+0xc8/0x290 (?:?)\n cgroup_update_frozen+0x9d/0x320 (?:?)\n lockdep_hardirqs_on_prepare+0xea/0x1a0 (?:?)\n trace_hardirqs_on+0x1a/0x170 (?:?)\n _raw_spin_unlock_irq+0x28/0x50 (?:?)\n do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)"
}
],
"id": "CVE-2026-63814",
"lastModified": "2026-07-20T15:16:48.207",
"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"
}
]
},
"published": "2026-07-19T12:16:54.390",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1ddf3fd21c4c652f9cab5552515c04a166662306"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/442ca20c54038e2400cf28aaa944cf1de2c8e65d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4e2a96ec7236e248e706850568e0a925fd21b588"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5d8a39649947a4e86c8fbc682d7fc0041b8d109a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/733cd8474e6d763d75ed96f3f2b98a25480cf2b9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/aba4f94ac1832c7299c33e1b4fe5f87eef6dc8f1"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c4810ada31e80cbe4011467c4f3b1e93f94134f3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ff83de56882cb8466184d322abece2589258ca56"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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