This is a note to let you know that I've just added the patch titled xfs: don't crash on unexpected holes in dir/attr btrees to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xfs-don-t-crash-on-unexpected-holes-in-dir-attr-btrees.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From hch@xxxxxx Mon Sep 18 10:07:57 2017 From: Christoph Hellwig <hch@xxxxxx> Date: Sun, 17 Sep 2017 14:06:35 -0700 Subject: xfs: don't crash on unexpected holes in dir/attr btrees To: stable@xxxxxxxxxxxxxxx Cc: linux-xfs@xxxxxxxxxxxxxxx, "Darrick J. Wong" <darrick.wong@xxxxxxxxxx> Message-ID: <20170917210712.10804-11-hch@xxxxxx> From: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx> commit cd87d867920155911d0d2e6485b769d853547750 upstream. In quite a few places we call xfs_da_read_buf with a mappedbno that we don't control, then assume that the function passes back either an error code or a buffer pointer. Unfortunately, if mappedbno == -2 and bno maps to a hole, we get a return code of zero and a NULL buffer, which means that we crash if we actually try to use that buffer pointer. This happens immediately when we set the buffer type for transaction context. Therefore, check that we have no error code and a non-NULL bp before trying to use bp. This patch is a follow-up to an incomplete fix in 96a3aefb8ffde231 ("xfs: don't crash if reading a directory results in an unexpected hole"). Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- fs/xfs/libxfs/xfs_da_btree.c | 2 +- fs/xfs/libxfs/xfs_dir2_block.c | 2 +- fs/xfs/libxfs/xfs_dir2_leaf.c | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -351,7 +351,7 @@ xfs_attr3_leaf_read( err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp, XFS_ATTR_FORK, &xfs_attr3_leaf_buf_ops); - if (!err && tp) + if (!err && tp && *bpp) xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_ATTR_LEAF_BUF); return err; } --- a/fs/xfs/libxfs/xfs_da_btree.c +++ b/fs/xfs/libxfs/xfs_da_btree.c @@ -263,7 +263,7 @@ xfs_da3_node_read( err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp, which_fork, &xfs_da3_node_buf_ops); - if (!err && tp) { + if (!err && tp && *bpp) { struct xfs_da_blkinfo *info = (*bpp)->b_addr; int type; --- a/fs/xfs/libxfs/xfs_dir2_block.c +++ b/fs/xfs/libxfs/xfs_dir2_block.c @@ -139,7 +139,7 @@ xfs_dir3_block_read( err = xfs_da_read_buf(tp, dp, mp->m_dir_geo->datablk, -1, bpp, XFS_DATA_FORK, &xfs_dir3_block_buf_ops); - if (!err && tp) + if (!err && tp && *bpp) xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_BLOCK_BUF); return err; } --- a/fs/xfs/libxfs/xfs_dir2_leaf.c +++ b/fs/xfs/libxfs/xfs_dir2_leaf.c @@ -268,7 +268,7 @@ xfs_dir3_leaf_read( err = xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp, XFS_DATA_FORK, &xfs_dir3_leaf1_buf_ops); - if (!err && tp) + if (!err && tp && *bpp) xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_LEAF1_BUF); return err; } @@ -285,7 +285,7 @@ xfs_dir3_leafn_read( err = xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp, XFS_DATA_FORK, &xfs_dir3_leafn_buf_ops); - if (!err && tp) + if (!err && tp && *bpp) xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_LEAFN_BUF); return err; } Patches currently in stable-queue which might be from hch@xxxxxx are queue-4.9/xfs-fix-inobt-inode-allocation-search-optimization.patch queue-4.9/xfs-try-to-avoid-blowing-out-the-transaction-reservation-when-bunmaping-a-shared-extent.patch queue-4.9/xfs-free-cowblocks-and-retry-on-buffered-write-enospc.patch queue-4.9/xfs-set-firstfsb-to-nullfsblock-before-feeding-it-to-_bmapi_write.patch queue-4.9/xfs-fix-quotacheck-dquot-id-overflow-infinite-loop.patch queue-4.9/xfs-remove-bli-from-ail-before-release-on-transaction-abort.patch queue-4.9/xfs-check-_btree_check_block-value.patch queue-4.9/xfs-don-t-allow-bmap-on-rt-files.patch queue-4.9/xfs-free-uncommitted-transactions-during-log-recovery.patch queue-4.9/xfs-don-t-crash-on-unexpected-holes-in-dir-attr-btrees.patch queue-4.9/xfs-fix-spurious-spin_is_locked-assert-failures-on-non-smp-kernels.patch queue-4.9/xfs-fix-per-inode-dax-flag-inheritance.patch queue-4.9/xfs-fix-multi-ag-deadlock-in-xfs_bunmapi.patch queue-4.9/xfs-release-bli-from-transaction-properly-on-fs-shutdown.patch queue-4.9/xfs-check-_alloc_read_agf-buffer-pointer-before-using.patch