smb: client: validate dacloffset before building DACL pointers
In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building DACL pointers parse_sec_desc(), build_sec_desc(), and the chown path in id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd before proving a DACL header fits inside the returned security descriptor. On 32-bit builds a malicious server can return dacloffset near U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip past the later pointer-based bounds checks. build_sec_desc() and id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped pointer in the chmod/chown rewrite paths. Validate dacloffset numerically before building any DACL pointer and reuse the same helper at the three DACL entry points.
CVE-2026-46195
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-2026-46195
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": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "5de2665e913a10ad70aaeecf736b97276e83d995",
"versionType": "git"
},
{
"status": "affected",
"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "f9dc3be8f403c1216df73e57221f44b045e7ee0b",
"versionType": "git"
},
{
"status": "affected",
"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "ba7f71b6161c0943dafc367565e5843d16b7d505",
"versionType": "git"
},
{
"status": "affected",
"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "3b1ddba19e77ee35241cd27f16dc3e8d14e08db7",
"versionType": "git"
},
{
"status": "affected",
"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "c688f3ed73d31943334ad2139cb02ec49664322a",
"versionType": "git"
},
{
"status": "affected",
"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "8bd07e417b6bda67e317920584e48cb6ee442a8a",
"versionType": "git"
},
{
"status": "affected",
"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
"lessThan": "f98b48151cc502ada59d9778f0112d21f2586ca3",
"versionType": "git"
}
],
"programFiles": [
"fs/smb/client/cifsacl.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.88",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/cifsacl.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-46195
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #40153 · Revision 1
- Added to Heist Feed
- Publisher date