• Kuniyuki Iwashima's avatar
    net: Remove WARN_ON_ONCE(sk->sk_forward_alloc) from sk_stream_kill_queues(). · 62ec33b4
    Kuniyuki Iwashima authored
    Christoph Paasch reported that commit b5fc2923 ("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: b5fc2923 ("inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().")
    Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
    Reported-by: default avatarChristoph Paasch <christophpaasch@icloud.com>
    Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
    Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    62ec33b4
caif_socket.c 26.5 KB