CVE-2026-98984
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: dcache: don't put a mountpoint on a dentry that's being removed rmdir(), unlink() and rename() call dont_mount() on the victim and then detach_mounts() with the victim's inode locked. do_lock_mount() takes the inode lock of the mountpoint and checks cant_mount() so a mount can't show up after detach_mounts(). But attach_recursive_mnt() makes a second mountpoint for the root of the source mount so that the mounts already located at the destination can be put on top of it. No inode is locked for that one and d_set_mounted() only refuses a dentry that is unlinked. Between detach_mounts() and d_delete() the victim is still hashed: rmrace: b passed dont_mount() and detach_mounts(), sleeping T2: move_mount(S, /tmp/plcant/x, BENEATH) = 0 errno 0 () T1: rmdir(/tmp/plcant/d/b) = 0 errno 0 109 107 0:61 /d/b//deleted /tmp/plcant/x rw,relatime - tmpfs tmpfs rw 108 109 0:63 / /tmp/plcant/x rw,relatime - tmpfs T rw A bind mount of the directory that's being removed is moved beneath an existing mount while the rmdir() is located between the two calls. The mount ends up on the removed directory and nothing will ever detach it. Check cant_mount() in d_set_mounted() as well. dont_mount() raises the flag under d_lock before detach_mounts() runs so either the mountpoint is set first and detach_mounts() finds the mount or the flag is seen and the mount is refused.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-23 13:17:20.287000
Last modified
2026-10-30 13:21:34.167000
View original CVE JSON
{
"id": "CVE-2026-98984",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-23T13:17:20.287",
"lastModified": "2026-10-30T13:21:34.167",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndcache: don't put a mountpoint on a dentry that's being removed\n\nrmdir(), unlink() and rename() call dont_mount() on the victim and then\ndetach_mounts() with the victim's inode locked. do_lock_mount() takes\nthe inode lock of the mountpoint and checks cant_mount() so a mount\ncan't show up after detach_mounts().\n\nBut attach_recursive_mnt() makes a second mountpoint for the root of the\nsource mount so that the mounts already located at the destination can\nbe put on top of it. No inode is locked for that one and d_set_mounted()\nonly refuses a dentry that is unlinked. Between detach_mounts() and\nd_delete() the victim is still hashed:\n\n rmrace: b passed dont_mount() and detach_mounts(), sleeping\n T2: move_mount(S, /tmp/plcant/x, BENEATH) = 0 errno 0 ()\n T1: rmdir(/tmp/plcant/d/b) = 0 errno 0\n 109 107 0:61 /d/b//deleted /tmp/plcant/x rw,relatime - tmpfs tmpfs rw\n 108 109 0:63 / /tmp/plcant/x rw,relatime - tmpfs T rw\n\nA bind mount of the directory that's being removed is moved beneath an\nexisting mount while the rmdir() is located between the two calls. The\nmount ends up on the removed directory and nothing will ever detach it.\n\nCheck cant_mount() in d_set_mounted() as well. dont_mount() raises the\nflag under d_lock before detach_mounts() runs so either the mountpoint\nis set first and detach_mounts() finds the mount or the flag is seen and\nthe mount is refused."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/dcache.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "1064f874abc0d05eeed8993815f584d847b72486",
"lessThan": "25e3ce3e2ebdd8ed3fc19dc1f7e3bc487f9240f3",
"versionType": "git",
"status": "affected"
},
{
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},
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},
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{
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{
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{
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"versionType": "git",
"status": "affected"
},
{
"version": "808e83e5add13152bd4a88346487de68395c136b",
"versionType": "git",
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},
{
"version": "6de9d08a9718ee9c12ba6343c50141c2d633e3dc",
"versionType": "git",
"status": "affected"
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"lessThan": "4.2",
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},
{
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},
{
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"status": "affected"
},
{
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"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/dcache.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.11",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.11",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.273",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.224",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.113",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.11",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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}
]
}