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authorDarrick J. Wong <darrick.wong@oracle.com>2016-12-05 12:38:38 +1100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-30 09:35:18 +0200
commitc4cf86f69597d4547a736e3edd5b88ae61b68fa2 (patch)
tree3934f40cfd2bf48b77ee30a4498f936273c06d5a /fs
parent48da8f817b9db7909e5758257bdc84a6c611d99a (diff)
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xfs: don't allow di_size with high bit set
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.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Nikolay Borisov <n.borisov.lkml@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-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 1aabfda669b0..7183b7ea065b 100644
--- 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;