In btree_gc_rewrite_node(), pointer 'n' is not checked after it returns from btree_gc_rewrite_node(). There is potential possibility that 'n' is a non NULL ERR_PTR(), referencing such error code is not permitted in following code. Therefore a return value checking is necessary after 'n' is back from btree_node_alloc_replacement().

Signed-off-by: Coly Li colyli@suse.de Reported-by: Dan Carpenter dan.carpenter@linaro.org Cc: stable@vger.kernel.org --- drivers/md/bcache/btree.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index ae5cbb55861f..de8d552201dc 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1532,6 +1532,8 @@ static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op, return 0;

n = btree_node_alloc_replacement(replace, NULL); + if (IS_ERR(n)) + return 0;

/* recheck reserve after allocating replacement node */ if (btree_check_reserve(b, NULL)) {