smb: client: fix use-after-free in cifs_oplock_break
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free in cifs_oplock_break A race condition can occur in cifs_oplock_break() leading to a use-after-free of the cinode structure when unmounting: cifs_oplock_break() _cifsFileInfo_put(cfile) cifsFileInfo_put_final() cifs_sb_deactive() [last ref, start releasing sb] kill_sb() kill_anon_super() generic_shutdown_super() evict_inodes() dispose_list() evict() destroy_inode() call_rcu(&inode->i_rcu, i_callback) spin_lock(&cinode->open_file_lock) <- OK [later] i_callback() cifs_free_inode() kmem_cache_free(cinode) spin_unlock(&cinode->open_file_lock) <- UAF cifs_done_oplock_break(cinode) <- UAF The issue occurs when umount has already released its reference to the superblock. When _cifsFileInfo_put() calls cifs_sb_deactive(), this releases the last reference, triggering the immediate cleanup of all inodes under RCU. However, cifs_oplock_break() continues to access the cinode after this point, resulting in use-after-free. Fix this by holding an extra reference to the superblock during the entire oplock break operation. This ensures that the superblock and its inodes remain valid until the oplock break completes.
CVE-2025-38527
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-38527
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b98749cac4a695f084a5ff076f4510b23e353ecd",
"lessThan": "4256a483fe58af66a46cbf3dc48ff26e580d3308",
"versionType": "git"
},
{
"status": "affected",
"version": "b98749cac4a695f084a5ff076f4510b23e353ecd",
"lessThan": "0a4eec84d4d2c4085d4ed8630fd74e4b39033c1b",
"versionType": "git"
},
{
"status": "affected",
"version": "b98749cac4a695f084a5ff076f4510b23e353ecd",
"lessThan": "2baaf5bbab2ac474c4f92c10fcb3310f824db995",
"versionType": "git"
},
{
"status": "affected",
"version": "b98749cac4a695f084a5ff076f4510b23e353ecd",
"lessThan": "09bce2138a30ef10d8821c8c3f73a4ab7a5726bc",
"versionType": "git"
},
{
"status": "affected",
"version": "b98749cac4a695f084a5ff076f4510b23e353ecd",
"lessThan": "da11bd4b697b393a207f19a2ed7d382a811a3ddc",
"versionType": "git"
},
{
"status": "affected",
"version": "b98749cac4a695f084a5ff076f4510b23e353ecd",
"lessThan": "705c79101ccf9edea5a00d761491a03ced314210",
"versionType": "git"
},
{
"status": "affected",
"version": "2429fcf06d3cb962693868ab0a927c9038f12a2d",
"versionType": "git"
},
{
"status": "affected",
"version": "1ee4f2d7cdcd4508cc3cbe3b2622d7177b89da12",
"versionType": "git"
},
{
"status": "affected",
"version": "53fc31a4853e30d6e8f142b824f724da27ff3e40",
"versionType": "git"
},
{
"status": "affected",
"version": "8092ecc306d81186a64cda42411121f4d35aaff4",
"versionType": "git"
},
{
"status": "affected",
"version": "ebac4d0adf68f8962bd82fcf483936edd6ec095b",
"versionType": "git"
},
{
"status": "affected",
"version": "3.16.72",
"lessThan": "3.17",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.9.171",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.114",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.37",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.0.10",
"lessThan": "5.1",
"versionType": "semver"
}
],
"programFiles": [
"fs/smb/client/file.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.190",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.147",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.100",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.40",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.15.8",
"versionType": "semver",
"lessThanOrEqual": "6.15.*"
},
{
"status": "unaffected",
"version": "6.16",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/file.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-38527
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #30587 · Revision 1
- Added to Heist Feed
- Publisher date