159 lines
9.3 KiB
JSON
159 lines
9.3 KiB
JSON
{
|
|
"dataType": "CVE_RECORD",
|
|
"dataVersion": "5.2",
|
|
"cveMetadata": {
|
|
"cveId": "CVE-2026-89641",
|
|
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
|
"state": "PUBLISHED",
|
|
"assignerShortName": "Linux",
|
|
"dateReserved": "2026-09-11T19:38:34.740Z",
|
|
"datePublished": "2026-09-11T19:45:34.036Z",
|
|
"dateUpdated": "2026-10-19T08:50:13.143Z"
|
|
},
|
|
"containers": {
|
|
"cna": {
|
|
"providerMetadata": {
|
|
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
|
"shortName": "Linux",
|
|
"dateUpdated": "2026-10-19T08:50:13.143Z"
|
|
},
|
|
"descriptions": [
|
|
{
|
|
"lang": "en",
|
|
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: clear tcon after cifsFileInfo_put() in cifs_file_set_size()\n\nWhen the else branch of cifs_file_set_size() finds a writable file handle\nvia find_writable_file(), it borrows tcon and server from the handle's\ntlink, attempts the handle-based set_file_size() RPC, and then releases\nthe handle with cifsFileInfo_put().\n\nIf set_file_size() fails, execution falls through to the path-based\nfallback, which reuses the borrowed tcon and server under the\n\"if (tcon == NULL)\" guard. Since tcon is not NULL at that point, the\nguard is skipped. If cifsFileInfo_put() dropped the last reference on a\ntlink that was already removed from the tlink tree (TCON_LINK_IN_TREE\ncleared, as happens during reconnection or session teardown),\ncifs_put_tlink() will have freed tcon; the subsequent set_path_size()\ncall is then a use-after-free.\n\nSetting tcon = NULL after cifsFileInfo_put() causes the existing guard\nto take the cifs_sb_tlink() path, which acquires a fresh reference for\nthe path-based operation or fails cleanly if the session is gone."
|
|
}
|
|
],
|
|
"metrics": [
|
|
{
|
|
"cvssV3_1": {
|
|
"version": "3.1",
|
|
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
|
|
"baseScore": 7.8,
|
|
"baseSeverity": "HIGH"
|
|
},
|
|
"scenarios": [
|
|
{
|
|
"lang": "en",
|
|
"value": "AV:L - The UAF is in the CIFS client setattr path (fs/smb/client/inode.c cifs_file_set_size), reached only via local VFS truncate/setattr on a mounted SMB share (sys_truncate → vfs_truncate → notify_change → cifs_setattr), not via ksmbd or unsolicited SMB receive processing.\nAC:L - A local attacker controls both sides: keep a writable handle open, issue truncate(2) to hit the find_writable_file() else branch, fail handle-based set_file_size (controlled/malicious server or reconnect), and concurrently umount/teardown so TCON_LINK_IN_TREE is already cleared when cifsFileInfo_put() drops the last tlink ref.\nPR:L - Any unprivileged user with write access on an existing CIFS mount can invoke truncate(2); vfs_truncate only requires MAY_WRITE and setattr_prepare does not demand CAP_SYS_ADMIN. CIFS is not FS_USERNS_MOUNT, but the vulnerable path itself needs no init-namespace capability.\nUI:N - The attacker performs open/truncate (and optional umount) themselves on a reachable CIFS mount such as an enterprise automount or a share they mounted; no separate victim action is required at exploit time.\nS:U - This is a standard in-kernel heap use-after-free of struct cifs_tcon on the client host, enabling privilege escalation within the same kernel security authority and not a VM, IOMMU, or sandbox escape.\nC:H - After cifsFileInfo_put() can free tcon, set_path_size()/smb2_compound_op() reads the freed cifs_tcon; kernel UAF of this heap object enables reuse/spraying and arbitrary kernel memory disclosure.\nI:H - The same freed tcon is passed into SMB2 compound operations that write tcon fields and follow tcon->ses pointers, so heap spraying yields arbitrary write and potential control-flow hijack primitives.\nA:H - Use-after-free of tcon in the path-based set_path_size fallback causes kernel oops/panic even without full exploitation, fully denying availability."
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"affected": [
|
|
{
|
|
"product": "Linux",
|
|
"vendor": "Linux",
|
|
"defaultStatus": "unaffected",
|
|
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
|
|
"programFiles": [
|
|
"fs/smb/client/inode.c"
|
|
],
|
|
"versions": [
|
|
{
|
|
"version": "110fee6b9bb58a5c50047fc2594d415f741b591e",
|
|
"lessThan": "4f18c9e7ee464aaae5cd9fccdb943b3fcb4655d4",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "110fee6b9bb58a5c50047fc2594d415f741b591e",
|
|
"lessThan": "4bea15d9c7683218f57b8c1f5f0aa75cab76af8d",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "110fee6b9bb58a5c50047fc2594d415f741b591e",
|
|
"lessThan": "b96db32fed8dfb2478d7c208f89bf383beed1535",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"product": "Linux",
|
|
"vendor": "Linux",
|
|
"defaultStatus": "affected",
|
|
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
|
|
"programFiles": [
|
|
"fs/smb/client/inode.c"
|
|
],
|
|
"versions": [
|
|
{
|
|
"version": "6.18",
|
|
"status": "affected"
|
|
},
|
|
{
|
|
"version": "0",
|
|
"lessThan": "6.18",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "6.18.50",
|
|
"lessThanOrEqual": "6.18.*",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "7.2.4",
|
|
"lessThanOrEqual": "7.2.*",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "7.3",
|
|
"lessThanOrEqual": "*",
|
|
"status": "unaffected",
|
|
"versionType": "original_commit_for_fix"
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"cpeApplicability": [
|
|
{
|
|
"nodes": [
|
|
{
|
|
"operator": "OR",
|
|
"negate": false,
|
|
"cpeMatch": [
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.18",
|
|
"versionEndExcluding": "6.18.50"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.18",
|
|
"versionEndExcluding": "7.2.4"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.18",
|
|
"versionEndExcluding": "7.3"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"references": [
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/4f18c9e7ee464aaae5cd9fccdb943b3fcb4655d4"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/4bea15d9c7683218f57b8c1f5f0aa75cab76af8d"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/b96db32fed8dfb2478d7c208f89bf383beed1535"
|
|
}
|
|
],
|
|
"title": "cifs: clear tcon after cifsFileInfo_put() in cifs_file_set_size()",
|
|
"x_generator": {
|
|
"engine": "bippy-1.2.0"
|
|
}
|
|
}
|
|
}
|
|
} |