Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: NFSD: remove flawed WARN_ON_ONCE from nfsd_mode_check The header for commit e75b23f9e323 ("nfsd: check d_can_lookup in fh_verify of directories") details the assumption that justified adding the WARN_ON_ONCE to nfsd_mode_check(), that assumption is invalid (in the case of NFS reexport). When NFSD exports an NFS filesystem it is very possible for nfsd_mode_check() to encounter a @dentry that doesn't have i_op->lookup (see nfs_fhget()'s NFS_ATTR_FATTR_MOUNTPOINT and NFS_ATTR_FATTR_V4_REFERRAL handling, and d_flags_for_inode()). So remove nfsd_mode_check()'s WARN_ON_ONCE(). The nfserr_notdir return on that branch must stay. It guards the subsequent lookup_one_unlocked() -> __lookup_slow() path, which calls inode->i_op->lookup() with no NULL check, so returning nfserr_notdir is what keeps a client LOOKUP into such a @dentry from dereferencing a NULL method pointer.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before ae251937c6f0237e5b555a5e4ba4595b8206e865; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before e145e8d67a5d41c72d322e7f87ab474d39d9dfb7; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before 9f4434893a2783f7384d993cea883aff3fb7a52d; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before 2ef131323999539038e306773c8256403834361b; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before b55b4d880bb080fa10eb08ba21a5d8679b8102fe; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before 7ef182a8fe9c12b0d936880b1e504840639aa009; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before a275de3bac5635514ca830f2e46b5ff0e66b5c4c; affected e75b23f9e323b1e0759619c39d5a9f7a3a5d9d2c before aa0cf48a448c5a9fe1a1e880899ecd589ce39e6e |
| Linux / Linux | affected 4.8; unaffected 0 before 4.8; unaffected 5.10.270 through 5.10.*; unaffected 5.15.221 through 5.15.*; unaffected 6.1.188 through 6.1.*; unaffected 6.6.157 through 6.6.*; unaffected 6.12.109 through 6.12.*; unaffected 6.18.50 through 6.18.*; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/ae251937c6f0237e5b555a5e4ba4595b8206e865
- https://git.kernel.org/stable/c/e145e8d67a5d41c72d322e7f87ab474d39d9dfb7
- https://git.kernel.org/stable/c/9f4434893a2783f7384d993cea883aff3fb7a52d
- https://git.kernel.org/stable/c/2ef131323999539038e306773c8256403834361b
- https://git.kernel.org/stable/c/b55b4d880bb080fa10eb08ba21a5d8679b8102fe
- https://git.kernel.org/stable/c/7ef182a8fe9c12b0d936880b1e504840639aa009
- https://git.kernel.org/stable/c/a275de3bac5635514ca830f2e46b5ff0e66b5c4c
- https://git.kernel.org/stable/c/aa0cf48a448c5a9fe1a1e880899ecd589ce39e6e
ADP enrichment
No English description supplied.
No references supplied.