From 80c0b4210a963e31529e15bf90519708ec947596 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Tue, 3 Apr 2018 01:59:47 +0800 Subject: [PATCH] Btrfs: fix NULL pointer dereference in log_dir_items 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 Signed-off-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/tree-log.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c91babc6aa4b..c6bfa86e2f22 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3520,8 +3520,11 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans, * 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]); -- 2.30.2