Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: nfsd: release path refs on follow_down() error nfsd_cross_mnt() initializes a local struct path with mntget() and dget() before calling follow_down(). On a negative return the error arm jumps to out without releasing those references: err = follow_down(&path, follow_flags); if (err < 0) goto out; follow_down() never drops the caller's entry-time refs on any error sub-case; for example a pre-cross d_manage() failure leaves path untouched, so the mntget()/dget() taken on entry survive the call. Every other early-exit arm in nfsd_cross_mnt() (other-namespace return, IS_ERR(exp2), and the success tail after the swap) already calls path_put(&path); the err < 0 arm is the lone omission. The leak inflates mnt_count and d_count on each failed cross-mount, blocking umount and pinning dentries against the shrinker, and is reachable by any authenticated NFS client through nfsd_lookup_dentry or the NFSv4 READDIR encode path. Fix by calling path_put(&path) before the goto out in the err < 0 arm so the entry-time refs are released on all follow_down() error returns.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected cc53ce53c86924bfe98a12ea20b7465038a08792 before 085cfde7c2186acaad103f02d2c25435ad5224e9; affected cc53ce53c86924bfe98a12ea20b7465038a08792 before 194316df81263519156ebe714c4a286bee00e5be; affected cc53ce53c86924bfe98a12ea20b7465038a08792 before 467d56fd3ff57447a790c6dc3ede2d02a947d224; affected cc53ce53c86924bfe98a12ea20b7465038a08792 before 2bc4343308d85ee4e0dd3877b384306c96f114c2; affected cc53ce53c86924bfe98a12ea20b7465038a08792 before 6cba08dc1922140d260cfeb30bbda4ee1bf869d8 |
| Linux / Linux | affected 2.6.38; unaffected 0 before 2.6.38; 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/085cfde7c2186acaad103f02d2c25435ad5224e9
- https://git.kernel.org/stable/c/194316df81263519156ebe714c4a286bee00e5be
- https://git.kernel.org/stable/c/467d56fd3ff57447a790c6dc3ede2d02a947d224
- https://git.kernel.org/stable/c/2bc4343308d85ee4e0dd3877b384306c96f114c2
- https://git.kernel.org/stable/c/6cba08dc1922140d260cfeb30bbda4ee1bf869d8
ADP enrichment
No English description supplied.
No references supplied.