| From: Liu Bo <bo.li.liu@oracle.com> |
| Date: Wed, 14 Sep 2016 17:23:24 -0700 |
| Subject: Btrfs: improve check_node to avoid reading corrupted nodes |
| |
| commit 6b722c1747d533ac6d4df110dc8233db46918b65 upstream. |
| |
| We need to check items in a node to make sure that we're reading |
| a valid one, otherwise we could get various crashes while processing |
| delayed_refs. |
| |
| Signed-off-by: Liu Bo <bo.li.liu@oracle.com> |
| Reviewed-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| fs/btrfs/disk-io.c | 32 ++++++++++++++++++++++++++++---- |
| 1 file changed, 28 insertions(+), 4 deletions(-) |
| |
| --- a/fs/btrfs/disk-io.c |
| +++ b/fs/btrfs/disk-io.c |
| @@ -508,9 +508,10 @@ static int check_tree_block_fsid(struct |
| } |
| |
| #define CORRUPT(reason, eb, root, slot) \ |
| - btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu," \ |
| - "root=%llu, slot=%d", reason, \ |
| - btrfs_header_bytenr(eb), root->objectid, slot) |
| + btrfs_crit(root->fs_info, "corrupt %s, %s: block=%llu," \ |
| + " root=%llu, slot=%d", \ |
| + btrfs_header_level(eb) == 0 ? "leaf" : "node",\ |
| + reason, btrfs_header_bytenr(eb), root->objectid, slot) |
| |
| static noinline int check_leaf(struct btrfs_root *root, |
| struct extent_buffer *leaf) |
| @@ -601,6 +602,10 @@ static noinline int check_leaf(struct bt |
| static int check_node(struct btrfs_root *root, struct extent_buffer *node) |
| { |
| unsigned long nr = btrfs_header_nritems(node); |
| + struct btrfs_key key, next_key; |
| + int slot; |
| + u64 bytenr; |
| + int ret = 0; |
| |
| if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root)) { |
| btrfs_crit(root->fs_info, |
| @@ -608,7 +613,26 @@ static int check_node(struct btrfs_root |
| node->start, root->objectid, nr); |
| return -EIO; |
| } |
| - return 0; |
| + |
| + for (slot = 0; slot < nr - 1; slot++) { |
| + bytenr = btrfs_node_blockptr(node, slot); |
| + btrfs_node_key_to_cpu(node, &key, slot); |
| + btrfs_node_key_to_cpu(node, &next_key, slot + 1); |
| + |
| + if (!bytenr) { |
| + CORRUPT("invalid item slot", node, root, slot); |
| + ret = -EIO; |
| + goto out; |
| + } |
| + |
| + if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) { |
| + CORRUPT("bad key order", node, root, slot); |
| + ret = -EIO; |
| + goto out; |
| + } |
| + } |
| +out: |
| + return ret; |
| } |
| |
| static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, |