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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2020-09-26 03:39:51 +0300 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2020-10-07 18:40:28 +0300 |
| commit | ff4ab5e02a0447dd1e290883eb6cd7d94848e590 (patch) | |
| tree | 59451bf62ddec9ce297594b6500ae56b2586d46d /fs/xfs/libxfs/xfs_defer.h | |
| parent | 64a3f3315bc60f710a0a25c1798ac0ea58c6fa1f (diff) | |
| download | linux-ff4ab5e02a0447dd1e290883eb6cd7d94848e590.tar.xz | |
xfs: fix an incore inode UAF in xfs_bui_recover
In xfs_bui_item_recover, there exists a use-after-free bug with regards
to the inode that is involved in the bmap replay operation. If the
mapping operation does not complete, we call xfs_bmap_unmap_extent to
create a deferred op to finish the unmapping work, and we retain a
pointer to the incore inode.
Unfortunately, the very next thing we do is commit the transaction and
drop the inode. If reclaim tears down the inode before we try to finish
the defer ops, we dereference garbage and blow up. Therefore, create a
way to join inodes to the defer ops freezer so that we can maintain the
xfs_inode reference until we're done with the inode.
Note: This imposes the requirement that there be enough memory to keep
every incore inode in memory throughout recovery.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/libxfs/xfs_defer.h')
| -rw-r--r-- | fs/xfs/libxfs/xfs_defer.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h index 6cde6f0713f7..05472f71fffe 100644 --- a/fs/xfs/libxfs/xfs_defer.h +++ b/fs/xfs/libxfs/xfs_defer.h @@ -82,6 +82,12 @@ struct xfs_defer_capture { /* Log reservation saved from the transaction. */ unsigned int dfc_logres; + + /* + * An inode reference that must be maintained to complete the deferred + * work. + */ + struct xfs_inode *dfc_capture_ip; }; /* @@ -89,8 +95,9 @@ struct xfs_defer_capture { * This doesn't normally happen except log recovery. */ int xfs_defer_ops_capture_and_commit(struct xfs_trans *tp, - struct list_head *capture_list); -void xfs_defer_ops_continue(struct xfs_defer_capture *d, struct xfs_trans *tp); + struct xfs_inode *capture_ip, struct list_head *capture_list); +void xfs_defer_ops_continue(struct xfs_defer_capture *d, struct xfs_trans *tp, + struct xfs_inode **captured_ipp); void xfs_defer_ops_release(struct xfs_mount *mp, struct xfs_defer_capture *d); #endif /* __XFS_DEFER_H__ */ |