4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Sandeen <sandeen@xxxxxxxxxxx>
commit 93e8befc17f6d6ea92b0aee3741ceac8bca4590f upstream.
Jason reported that a corrupted filesystem failed to replay
the log with a metadata block out of bounds warning:
XFS (dm-2): _xfs_buf_find: Block out of range: block 0x80270fff8, EOFS 0x9c40000
_xfs_buf_find() and xfs_btree_get_bufs() return NULL if
that happens, and then when xfs_alloc_fix_freelist() calls
xfs_trans_binval() on that NULL bp, we oops with:
BUG: unable to handle kernel NULL pointer dereference at 00000000000000f8
We don't handle _xfs_buf_find errors very well, every
caller higher up the stack gets to guess at why it failed.
But we should at least handle it somehow, so return
EFSCORRUPTED here.
Reported-by: Jason L Tibbitts III <tibbs@xxxxxxxxxxx>
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/libxfs/xfs_alloc.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1579,6 +1579,10 @@ xfs_alloc_ag_vextent_small(
bp = xfs_btree_get_bufs(args->mp, args->tp,
args->agno, fbno, 0);
+ if (!bp) {
+ error = -EFSCORRUPTED;
+ goto error0;
+ }
xfs_trans_binval(args->tp, bp);
}
args->len = 1;
@@ -2136,6 +2140,10 @@ xfs_alloc_fix_freelist(
if (error)
goto out_agbp_relse;
bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
+ if (!bp) {
+ error = -EFSCORRUPTED;
+ goto out_agbp_relse;
+ }
xfs_trans_binval(tp, bp);
}