Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before 5de2665e913a10ad70aaeecf736b97276e83d995; affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before f9dc3be8f403c1216df73e57221f44b045e7ee0b; affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before ba7f71b6161c0943dafc367565e5843d16b7d505; affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before 3b1ddba19e77ee35241cd27f16dc3e8d14e08db7; affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before c688f3ed73d31943334ad2139cb02ec49664322a; affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before 8bd07e417b6bda67e317920584e48cb6ee442a8a; affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 before f98b48151cc502ada59d9778f0112d21f2586ca3 |
| Linux / Linux | affected 5.12; unaffected 0 before 5.12; unaffected 5.15.210 through 5.15.*; unaffected 6.1.176 through 6.1.*; unaffected 6.6.140 through 6.6.*; unaffected 6.12.88 through 6.12.*; unaffected 6.18.30 through 6.18.*; unaffected 7.0.7 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995
- https://git.kernel.org/stable/c/f9dc3be8f403c1216df73e57221f44b045e7ee0b
- https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505
- https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7
- https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a
- https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a
- https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3
ADP enrichment
A flaw was found in the Linux kernel's Server Message Block (SMB) client. A malicious server can exploit this vulnerability on 32-bit systems by providing a crafted dacloffset value. This can cause a pointer wrap, leading to the dereferencing of invalid Discretionary Access Control List (DACL) fields during chmod or chown operations. This memory corruption could potentially allow the malicious server to bypass security mechanisms or cause a denial of service.
- https://access.redhat.com/security/cve/CVE-2026-46195
- https://bugzilla.redhat.com/show_bug.cgi?id=2482606
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46195.json
- https://access.redhat.com/errata/RHSA-2026:21556
- https://access.redhat.com/errata/RHSA-2026:21706
- https://access.redhat.com/errata/RHSA-2026:21745
No English description supplied.
No English description supplied.
No references supplied.