Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: ksmbd: require 3 sub-authorities before reading sub_auth[2] parse_dacl() compares each ACE SID against sid_unix_NFS_mode and on match reads sid.sub_auth[2] as the file mode. If sid_unix_NFS_mode is the prefix S-1-5-88-3 with num_subauth = 2 then compare_sids() compares only min(num_subauth, 2) sub-authorities so a client SID with num_subauth = 2 and sub_auth = {88, 3} will match. If num_subauth = 2 and the ACE is placed at the very end of the security descriptor, sub_auth[2] will be 4 bytes past end_of_acl. The out-of-band bytes will then be masked to the low 9 bits and applied as the file's POSIX mode, probably not something that is good to have happen. Fix this up by forcing the SID to actually carry a third sub-authority before reading it at all.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before cf2148b880fb7c0fcd727202dbc4fd5d6998b9c2; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before b5b5d5936a50497fb151c0b122899a6894721c2b; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 08f9e6d899b5c834bbcc239eae1bed58d9b15d2c; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before d2454f4a002d08560a60f214f392e6491cf11560; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 46bbcd3ebfb3549c8da1838fc4493e79bd3241e7; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 9401f86a224f37b50e6a3ccf1d46a70d5ef8af0a; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 53370cf9090777774e07fd9a8ebce67c6cc333ab |
| Linux / Linux | affected 5.15; unaffected 0 before 5.15; unaffected 6.1.175 through 6.1.*; unaffected 6.6.136 through 6.6.*; unaffected 6.12.83 through 6.12.*; unaffected 6.18.24 through 6.18.*; unaffected 6.19.14 through 6.19.*; unaffected 7.0.1 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/cf2148b880fb7c0fcd727202dbc4fd5d6998b9c2
- https://git.kernel.org/stable/c/b5b5d5936a50497fb151c0b122899a6894721c2b
- https://git.kernel.org/stable/c/08f9e6d899b5c834bbcc239eae1bed58d9b15d2c
- https://git.kernel.org/stable/c/d2454f4a002d08560a60f214f392e6491cf11560
- https://git.kernel.org/stable/c/46bbcd3ebfb3549c8da1838fc4493e79bd3241e7
- https://git.kernel.org/stable/c/9401f86a224f37b50e6a3ccf1d46a70d5ef8af0a
- https://git.kernel.org/stable/c/53370cf9090777774e07fd9a8ebce67c6cc333ab
ADP enrichment
No English description supplied.