Re: [PATCH 6.6.y] net: fix data-races around sk->sk_forward_alloc

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 073d89808c065ac4c672c0a613a71b27a80691cb

WARNING: Author mismatch between patch and upstream commit:
Backport author: alvalan9@foxmail.com
Commit author: Wang Liang<wangliang74@huawei.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Not found

Note: The patch differs from the upstream commit:
---
1:  073d89808c065 ! 1:  fbdaa519ebbda net: fix data-races around sk->sk_forward_alloc
    @@ Metadata
      ## Commit message ##
         net: fix data-races around sk->sk_forward_alloc
     
    +    commit 073d89808c065ac4c672c0a613a71b27a80691cb upstream.
    +
         Syzkaller reported this warning:
          ------------[ cut here ]------------
          WARNING: CPU: 0 PID: 16 at net/ipv4/af_inet.c:156 inet_sock_destruct+0x1c5/0x1e0
    @@ Commit message
         Signed-off-by: Wang Liang <wangliang74@huawei.com>
         Link: https://patch.msgid.link/20241107023405.889239-1-wangliang74@huawei.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    +    Signed-off-by: Alva Lan <alvalan9@foxmail.com>
     
      ## net/dccp/ipv6.c ##
     @@ net/dccp/ipv6.c: static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
    @@ net/ipv6/tcp_ipv6.c: int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
     +	if (np->rxopt.all && sk->sk_state != TCP_LISTEN)
      		opt_skb = skb_clone_and_charge_r(skb, sk);
      
    - 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
    + 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
     @@ net/ipv6/tcp_ipv6.c: int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
    - 				if (reason)
    - 					goto reset;
    - 			}
    + 		if (nsk != sk) {
    + 			if (tcp_child_process(sk, nsk, skb))
    + 				goto reset;
     -			if (opt_skb)
     -				__kfree_skb(opt_skb);
      			return 0;
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |