--- /dev/null
+From 35cd2598c910ad6a1cc8bd3f731429b1901abc63 Mon Sep 17 00:00:00 2001
+From: Kuniyuki Iwashima <kuniyu@amazon.com>
+Date: Mon, 27 Feb 2023 13:15:48 -0800
+Subject: [PATCH] net: Remove WARN_ON_ONCE(sk->sk_forward_alloc) from
+ sk_stream_kill_queues().
+
+commit 62ec33b44e0f7168ff2886520fec6fb62d03b5a3 upstream.
+
+Christoph Paasch reported that commit b5fc29233d28 ("inet6: Remove
+inet6_destroy_sock() in sk->sk_prot->destroy().") started triggering
+WARN_ON_ONCE(sk->sk_forward_alloc) in sk_stream_kill_queues(). [0 - 2]
+Also, we can reproduce it by a program in [3].
+
+In the commit, we delay freeing ipv6_pinfo.pktoptions from sk->destroy()
+to sk->sk_destruct(), so sk->sk_forward_alloc is no longer zero in
+inet_csk_destroy_sock().
+
+The same check has been in inet_sock_destruct() from at least v2.6,
+we can just remove the WARN_ON_ONCE(). However, among the users of
+sk_stream_kill_queues(), only CAIF is not calling inet_sock_destruct().
+Thus, we add the same WARN_ON_ONCE() to caif_sock_destructor().
+
+[0]: https://lore.kernel.org/netdev/39725AB4-88F1-41B3-B07F-949C5CAEFF4F@icloud.com/
+[1]: https://github.com/multipath-tcp/mptcp_net-next/issues/341
+[2]:
+WARNING: CPU: 0 PID: 3232 at net/core/stream.c:212 sk_stream_kill_queues+0x2f9/0x3e0
+Modules linked in:
+CPU: 0 PID: 3232 Comm: syz-executor.0 Not tainted 6.2.0-rc5ab24eb4698afbe147b424149c529e2a43ec24eb5 #2
+Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
+RIP: 0010:sk_stream_kill_queues+0x2f9/0x3e0
+Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e ec 00 00 00 8b ab 08 01 00 00 e9 60 ff ff ff e8 d0 5f b6 fe 0f 0b eb 97 e8 c7 5f b6 fe <0f> 0b eb a0 e8 be 5f b6 fe 0f 0b e9 6a fe ff ff e8 02 07 e3 fe e9
+RSP: 0018:ffff88810570fc68 EFLAGS: 00010293
+RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
+RDX: ffff888101f38f40 RSI: ffffffff8285e529 RDI: 0000000000000005
+RBP: 0000000000000ce0 R08: 0000000000000005 R09: 0000000000000000
+R10: 0000000000000ce0 R11: 0000000000000001 R12: ffff8881009e9488
+R13: ffffffff84af2cc0 R14: 0000000000000000 R15: ffff8881009e9458
+FS: 00007f7fdfbd5800(0000) GS:ffff88811b600000(0000) knlGS:0000000000000000
+CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+CR2: 0000001b32923000 CR3: 00000001062fc006 CR4: 0000000000170ef0
+Call Trace:
+ <TASK>
+ inet_csk_destroy_sock+0x1a1/0x320
+ __tcp_close+0xab6/0xe90
+ tcp_close+0x30/0xc0
+ inet_release+0xe9/0x1f0
+ inet6_release+0x4c/0x70
+ __sock_release+0xd2/0x280
+ sock_close+0x15/0x20
+ __fput+0x252/0xa20
+ task_work_run+0x169/0x250
+ exit_to_user_mode_prepare+0x113/0x120
+ syscall_exit_to_user_mode+0x1d/0x40
+ do_syscall_64+0x48/0x90
+ entry_SYSCALL_64_after_hwframe+0x72/0xdc
+RIP: 0033:0x7f7fdf7ae28d
+Code: c1 20 00 00 75 10 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 37 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
+RSP: 002b:00000000007dfbb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
+RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f7fdf7ae28d
+RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003
+RBP: 0000000000000000 R08: 000000007f338e0f R09: 0000000000000e0f
+R10: 000000007f338e13 R11: 0000000000000293 R12: 00007f7fdefff000
+R13: 00007f7fdefffcd8 R14: 00007f7fdefffce0 R15: 00007f7fdefffcd8
+ </TASK>
+
+[3]: https://lore.kernel.org/netdev/20230208004245.83497-1-kuniyu@amazon.com/
+
+Fixes: b5fc29233d28 ("inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().")
+Reported-by: syzbot <syzkaller@googlegroups.com>
+Reported-by: Christoph Paasch <christophpaasch@icloud.com>
+Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
+Reviewed-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ net/caif/caif_socket.c | 1 +
+ net/core/stream.c | 1 -
+ 2 files changed, 1 insertion(+), 1 deletion(-)
+
+--- a/net/caif/caif_socket.c
++++ b/net/caif/caif_socket.c
+@@ -1020,6 +1020,7 @@ static void caif_sock_destructor(struct
+ return;
+ }
+ sk_stream_kill_queues(&cf_sk->sk);
++ WARN_ON(sk->sk_forward_alloc);
+ caif_free_client(&cf_sk->layer);
+ }
+
+--- a/net/core/stream.c
++++ b/net/core/stream.c
+@@ -209,7 +209,6 @@ void sk_stream_kill_queues(struct sock *
+ sk_mem_reclaim(sk);
+
+ WARN_ON(sk->sk_wmem_queued);
+- WARN_ON(sk->sk_forward_alloc);
+
+ /* It is _impossible_ for the backlog to contain anything
+ * when we get here. All user references to this socket
projects / openwrt / staging / hauke.git / commitdiff