4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Darrick J. Wong <darrick.w...@oracle.com>
commit ef388e2054feedaeb05399ed654bdb06f385d294 upstream.
The on-disk field di_size is used to set i_size, which is a signed
integer of loff_t. If the high bit of di_size is set, we'll end up with
a negative i_size, which will cause all sorts of problems. Since the
VFS won't let us create a file with such length, we should catch them
here in the verifier too.
Signed-off-by: Darrick J. Wong <darrick.w...@oracle.com>
Reviewed-by: Dave Chinner <dchin...@redhat.com>
Signed-off-by: Dave Chinner <da...@fromorbit.com>
Cc: Nikolay Borisov <n.borisov.l...@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/xfs/libxfs/xfs_inode_buf.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -299,6 +299,14 @@ xfs_dinode_verify(
if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
return false;
+ /* don't allow invalid i_size */
+ if (be64_to_cpu(dip->di_size) & (1ULL << 63))
+ return false;
+
+ /* No zero-length symlinks. */
+ if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0)
+ return false;
+
/* only version 3 or greater inodes are extensively verified here */
if (dip->di_version < 3)
return true;
