| From: Liu Bo <bo.liu@linux.alibaba.com> |
| Date: Tue, 3 Apr 2018 01:59:47 +0800 |
| Subject: Btrfs: fix NULL pointer dereference in log_dir_items |
| |
| commit 80c0b4210a963e31529e15bf90519708ec947596 upstream. |
| |
| 0, 1 and <0 can be returned by btrfs_next_leaf(), and when <0 is |
| returned, path->nodes[0] could be NULL, log_dir_items lacks such a |
| check for <0 and we may run into a null pointer dereference panic. |
| |
| Fixes: e02119d5a7b4 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") |
| Reviewed-by: Nikolay Borisov <nborisov@suse.com> |
| Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> |
| Signed-off-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| fs/btrfs/tree-log.c | 7 +++++-- |
| 1 file changed, 5 insertions(+), 2 deletions(-) |
| |
| --- a/fs/btrfs/tree-log.c |
| +++ b/fs/btrfs/tree-log.c |
| @@ -3082,8 +3082,11 @@ static noinline int log_dir_items(struct |
| * from this directory and from this transaction |
| */ |
| ret = btrfs_next_leaf(root, path); |
| - if (ret == 1) { |
| - last_offset = (u64)-1; |
| + if (ret) { |
| + if (ret == 1) |
| + last_offset = (u64)-1; |
| + else |
| + err = ret; |
| goto done; |
| } |
| btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); |
