Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential deadlock with newly created symlinks Syzbot reported that page_symlink(), called by nilfs_symlink(), triggers memory reclamation involving the filesystem layer, which can result in circular lock dependencies among the reader/writer semaphore nilfs->ns_segctor_sem, s_writers percpu_rwsem (intwrite) and the fs_reclaim pseudo lock. This is because after commit 21fc61c73c39 ("don't put symlink bodies in pagecache into highmem"), the gfp flags of the page cache for symbolic links are overwritten to GFP_KERNEL via inode_nohighmem(). This is not a problem for symlinks read from the backing device, because the __GFP_FS flag is dropped after inode_nohighmem() is called. However, when a new symlink is created with nilfs_symlink(), the gfp flags remain overwritten to GFP_KERNEL. Then, memory allocation called from page_symlink() etc. triggers memory reclamation including the FS layer, which may call nilfs_evict_inode() or nilfs_dirty_inode(). And these can cause a deadlock if they are called while nilfs->ns_segctor_sem is held: Fix this issue by dropping the __GFP_FS flag from the page cache GFP flags of newly created symlinks in the same way that nilfs_new_inode() and __nilfs_read_inode() do, as a workaround until we adopt nofs allocation scope consistently or improve the locking constraints.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before cc38c596e648575ce58bfc31623a6506eda4b94a; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before a1686db1e59f8fc016c4c9361e2119dd206f479a; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before c72e0df0b56c1166736dc8eb62070ebb12591447; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before 69548bb663fcb63f9ee0301be808a36b9d78dac3; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before 58c7f44c7b9e5ac7e3b1e5da2572ed7767a12f38; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before 1246d86e7bbde265761932c6e2dce28c69cdcb91; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before 9aa5d43ac4cace8fb9bd964ff6c23f599dc3cd24; affected 21fc61c73c3903c4c312d0802da01ec2b323d174 before b3a033e3ecd3471248d474ef263aadc0059e516a; affected 076e4ab3279eb3ddb206de44d04df7aeb2428e09; affected 4.4.116 before 4.5 |
| Linux / Linux | affected 4.5; unaffected 0 before 4.5; unaffected 4.19.323 through 4.19.*; unaffected 5.4.285 through 5.4.*; unaffected 5.10.229 through 5.10.*; unaffected 5.15.171 through 5.15.*; unaffected 6.1.116 through 6.1.*; unaffected 6.6.60 through 6.6.*; unaffected 6.11.7 through 6.11.*; unaffected 6.12 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/cc38c596e648575ce58bfc31623a6506eda4b94a
- https://git.kernel.org/stable/c/a1686db1e59f8fc016c4c9361e2119dd206f479a
- https://git.kernel.org/stable/c/c72e0df0b56c1166736dc8eb62070ebb12591447
- https://git.kernel.org/stable/c/69548bb663fcb63f9ee0301be808a36b9d78dac3
- https://git.kernel.org/stable/c/58c7f44c7b9e5ac7e3b1e5da2572ed7767a12f38
- https://git.kernel.org/stable/c/1246d86e7bbde265761932c6e2dce28c69cdcb91
- https://git.kernel.org/stable/c/9aa5d43ac4cace8fb9bd964ff6c23f599dc3cd24
- https://git.kernel.org/stable/c/b3a033e3ecd3471248d474ef263aadc0059e516a
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.