net/unix/af_unix.c:2471 manage_oob() warn: returning freed memory 'skb'
From: Dan Carpenter
Date: Tue Nov 30 2021 - 08:04:33 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: a4849f6000e29235a2707f22e39da6b897bb9543
commit: 314001f0bf927015e459c9d387d62a231fe93af3 af_unix: Add OOB support
config: openrisc-randconfig-m031-20211123 (https://download.01.org/0day-ci/archive/20211126/202111261743.2W1C2ZA9-lkp@xxxxxxxxx/config)
compiler: or1k-linux-gcc (GCC) 11.2.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
smatch warnings:
net/unix/af_unix.c:2471 manage_oob() warn: returning freed memory 'skb'
vim +/skb +2471 net/unix/af_unix.c
314001f0bf92701 Rao Shoaib 2021-08-01 2446 static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk,
314001f0bf92701 Rao Shoaib 2021-08-01 2447 int flags, int copied)
314001f0bf92701 Rao Shoaib 2021-08-01 2448 {
314001f0bf92701 Rao Shoaib 2021-08-01 2449 struct unix_sock *u = unix_sk(sk);
314001f0bf92701 Rao Shoaib 2021-08-01 2450
314001f0bf92701 Rao Shoaib 2021-08-01 2451 if (!unix_skb_len(skb) && !(flags & MSG_PEEK)) {
314001f0bf92701 Rao Shoaib 2021-08-01 2452 skb_unlink(skb, &sk->sk_receive_queue);
314001f0bf92701 Rao Shoaib 2021-08-01 2453 consume_skb(skb);
314001f0bf92701 Rao Shoaib 2021-08-01 2454 skb = NULL;
314001f0bf92701 Rao Shoaib 2021-08-01 2455 } else {
314001f0bf92701 Rao Shoaib 2021-08-01 2456 if (skb == u->oob_skb) {
314001f0bf92701 Rao Shoaib 2021-08-01 2457 if (copied) {
314001f0bf92701 Rao Shoaib 2021-08-01 2458 skb = NULL;
314001f0bf92701 Rao Shoaib 2021-08-01 2459 } else if (sock_flag(sk, SOCK_URGINLINE)) {
314001f0bf92701 Rao Shoaib 2021-08-01 2460 if (!(flags & MSG_PEEK)) {
314001f0bf92701 Rao Shoaib 2021-08-01 2461 u->oob_skb = NULL;
314001f0bf92701 Rao Shoaib 2021-08-01 2462 consume_skb(skb);
skb = NULL?
314001f0bf92701 Rao Shoaib 2021-08-01 2463 }
314001f0bf92701 Rao Shoaib 2021-08-01 2464 } else if (!(flags & MSG_PEEK)) {
314001f0bf92701 Rao Shoaib 2021-08-01 2465 skb_unlink(skb, &sk->sk_receive_queue);
314001f0bf92701 Rao Shoaib 2021-08-01 2466 consume_skb(skb);
314001f0bf92701 Rao Shoaib 2021-08-01 2467 skb = skb_peek(&sk->sk_receive_queue);
314001f0bf92701 Rao Shoaib 2021-08-01 2468 }
314001f0bf92701 Rao Shoaib 2021-08-01 2469 }
314001f0bf92701 Rao Shoaib 2021-08-01 2470 }
314001f0bf92701 Rao Shoaib 2021-08-01 @2471 return skb;
314001f0bf92701 Rao Shoaib 2021-08-01 2472 }
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0-DAY CI Kernel Test Service, Intel Corporation
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