xfs: verify COW extent size hint is valid in inode verifier

Source kernel commit: 02a0fda875c89e826c9f9f7e6861a0314d6a6b7d

There are rules for vald extent size hints. We enforce them when
applications set them, but fuzzers violate those rules and that
screws us over. Validate COW extent size hint rules in the inode
verifier to catch this.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_inode_buf.c b/libxfs/xfs_inode_buf.c
index 5b8d3024a0b0d9ad549fe648a835314477cf2398..062776a23afbacaf6636e91a6b4efa642302e445 100644 (file)
--- a/libxfs/xfs_inode_buf.c
+++ b/libxfs/xfs_inode_buf.c
@@ -539,6 +539,12 @@ xfs_dinode_verify(
        if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags2 & XFS_DIFLAG2_DAX))
                return __this_address;
 
+       /* COW extent size hint validation */
+       fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize),
+                       mode, flags, flags2);
+       if (fa)
+               return fa;
+
        return NULL;
 }