From 4a8b24ed1050b81e7fda527cbf4a0f645cadbcbb Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Mon, 22 Feb 2016 22:56:33 +0100 Subject: [PATCH] batman-adv: Fix unexpected free of bcast_own on add_if error commit f7dcdf5fdbe8fec7670d8f65a5db595c98e0ecab upstream. The function batadv_iv_ogm_orig_add_if allocates new buffers for bcast_own and bcast_own_sum. It is expected that these buffers are unchanged in case either bcast_own or bcast_own_sum couldn't be resized. But the error handling of this function frees the already resized buffer for bcast_own when the allocation of the new bcast_own_sum buffer failed. This will lead to an invalid memory access when some code will try to access bcast_own. Instead the resized new bcast_own buffer has to be kept. This will not lead to problems because the size of the buffer was only increased and therefore no user of the buffer will try to access bytes outside of the new buffer. Fixes: d0015fdd3d2c ("batman-adv: provide orig_node routing API") Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/batman-adv/bat_iv_ogm.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index f04224c32005a..8f36ccc1409ba 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -124,10 +124,8 @@ static int batadv_iv_ogm_orig_add_if(struct batadv_orig_node *orig_node, orig_node->bat_iv.bcast_own = data_ptr; data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC); - if (!data_ptr) { - kfree(orig_node->bat_iv.bcast_own); + if (!data_ptr) goto unlock; - } memcpy(data_ptr, orig_node->bat_iv.bcast_own_sum, (max_if_num - 1) * sizeof(uint8_t)); -- 2.47.3