Hello, The patch in the subject applies cleanly on 4.4 and I have attached the backport for 3.12. This causes hangs in both xfs/133 and xfs/134. As is customary - a battery of xfstests have been run to ensure no regressions were introduced. Regards, Nikolay
>From a8581aae46a02f329fce5678a5932d99e1c188e0 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx> Date: Mon, 5 Dec 2016 12:38:38 +1100 Subject: [PATCH] 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. [nborisov: Backported to 3.12] Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx> --- fs/xfs/xfs_inode_buf.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/xfs/xfs_inode_buf.c b/fs/xfs/xfs_inode_buf.c index 4b1447b3a9e4..8cc193ab434a 100644 --- a/fs/xfs/xfs_inode_buf.c +++ b/fs/xfs/xfs_inode_buf.c @@ -301,6 +301,14 @@ 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; -- 2.7.4