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authorDarrick J. Wong <darrick.wong@oracle.com>2016-12-05 12:38:38 +1100
committerDave Chinner <david@fromorbit.com>2016-12-05 12:38:38 +1100
commitef388e2054feedaeb05399ed654bdb06f385d294 (patch)
tree50b1ba9f23aa82d4d8299fb35b1d4b72df316c7e
parent0f352f8ee8412bd9d34fb2a6411241da61175c0e (diff)
xfs: don't allow di_size with high bit set
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.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
-rw-r--r--fs/xfs/libxfs/xfs_inode_buf.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index 134424fac434..c906e50515f0 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -392,6 +392,14 @@ 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;