Subject: general protection fault in finish_wait

From: syzbot <[email-masked]>
Date: Mon, 09 Jul 2018 04:49:02 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    6508b6781be0 tcp: cleanup copied_seq and urg_data in tcp_d..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=1256e6dc400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2ca6c7a31d407f86
dashboard link: https://syzkaller.appspot.com/bug?extid=3aac4a52d8e8ca0414d5
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1310fafc400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10af4f48400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 4.18.0-rc3+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events smc_tcp_listen_work
RIP: 0010:__lock_acquire+0x245/0x5020 kernel/locking/lockdep.c:3314
Code: 28 00 00 00 0f 85 03 34 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f  
5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f  
85 c6 35 00 00 49 81 7d 00 60 76 e7 89 0f 84 42 ff
RSP: 0000:ffff8801d9b36d20 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffffffff88f1b060
RBP: ffff8801d9b370a8 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8801d9b2a500 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000018 R14: ffff8801d9b2a500 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002cc0 CR3: 00000001ae03f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
  finish_wait+0x119/0x430 kernel/sched/wait.c:364
  inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:418 [inline]
  inet_csk_accept+0x6d0/0xe70 net/ipv4/inet_connection_sock.c:451
  inet_accept+0x138/0x9f0 net/ipv4/af_inet.c:734
  kernel_accept+0x136/0x310 net/socket.c:3251
  smc_clcsock_accept net/smc/af_smc.c:701 [inline]
  smc_tcp_listen_work+0x222/0xef0 net/smc/af_smc.c:1114
  process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153
  worker_thread+0x189/0x13c0 kernel/workqueue.c:2296
  kthread+0x345/0x410 kernel/kthread.c:240
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Modules linked in:
Dumping ftrace buffer:
    (ftrace buffer empty)
---[ end trace 472b359041f047a6 ]---
RIP: 0010:__lock_acquire+0x245/0x5020 kernel/locking/lockdep.c:3314
Code: 28 00 00 00 0f 85 03 34 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f  
5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f  
85 c6 35 00 00 49 81 7d 00 60 76 e7 89 0f 84 42 ff
RSP: 0000:ffff8801d9b36d20 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffffffff88f1b060
RBP: ffff8801d9b370a8 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8801d9b2a500 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000018 R14: ffff8801d9b2a500 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002cc0 CR3: 00000001ae03f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

---
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