Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate inherited ACE SID length smb_inherit_dacl() walks the parent directory DACL loaded from the security descriptor xattr. It verifies that each ACE contains the fixed SID header before using it, but does not verify that the variable-length SID described by sid.num_subauth is fully contained in the ACE. A malformed inheritable ACE can advertise more subauthorities than are present in the ACE. compare_sids() may then read past the ACE. smb_set_ace() also clamps the copied destination SID, but used the unchecked source SID count to compute the inherited ACE size. That could advance the temporary inherited ACE buffer pointer and nt_size accounting past the allocated buffer. Fix this by validating the parent ACE SID count and SID length before using the SID during inheritance. Compute the inherited ACE size from the copied SID so the size matches the bounded destination SID. Reject the inherited DACL if size accumulation would overflow smb_acl.size or the security descriptor allocation size.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to < 00f053d97b63591cafd791dce8d6c53e1625dad1affectede2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to < a7fb771314fb3a265d30f8ac245869a367ab065caffectede2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to < 47c6e37a77b10e74f70d845ba4ea5d3cafa00336affectede2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to < 1aa60fea7f637c071f529ad6784aecca2f2f0c5faffectede2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to < c1d95c995d5bcb24b639200a899eda59cb1e6d64affectede2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to < 996454bc0da84d5a1dedb1a7861823087e01a7aeaffected
Linux Linux
Default version status: affected
5.15affected0 to < 5.15unaffected6.1.191 to ≤ 6.1.*unaffected6.6.141 to ≤ 6.6.*unaffected6.12.88 to ≤ 6.12.*unaffected6.18.30 to ≤ 6.18.*unaffected7.0.7 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/00f053d97b63591cafd791dce8d6c53e1625dad1 ↗
- https://git.kernel.org/stable/c/a7fb771314fb3a265d30f8ac245869a367ab065c ↗
- https://git.kernel.org/stable/c/47c6e37a77b10e74f70d845ba4ea5d3cafa00336 ↗
- https://git.kernel.org/stable/c/1aa60fea7f637c071f529ad6784aecca2f2f0c5f ↗
- https://git.kernel.org/stable/c/c1d95c995d5bcb24b639200a899eda59cb1e6d64 ↗
- https://git.kernel.org/stable/c/996454bc0da84d5a1dedb1a7861823087e01a7ae ↗