[syzbot] general protection fault in kernel_accept (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bf682942cd26 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=117fc3ac880000
kernel config: https://syzkaller.appspot.com/x/.config?x=7db7ad17eb14cb7
dashboard link: https://syzkaller.appspot.com/bug?extid=c5ce866a8d30f4be0651
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c5ce86...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 3 PID: 12841 Comm: kworker/u16:2 Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: tipc_rcv tipc_topsrv_accept
RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e3 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 20 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ee 00 00 00 48 8b 7b 08 e8 a0 36 1c fa e8 8b ff
RSP: 0018:ffffc9000494fc28 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff874c37b2 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000449 R12: 0000000000000000
R13: ffff888027a7b980 R14: ffff888028bc08e0 R15: 1ffff92000929f90
FS: 0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa6e1a8c920 CR3: 000000004bba0000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460
process_one_work+0x991/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e3 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 20 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ee 00 00 00 48 8b 7b 08 e8 a0 36 1c fa e8 8b ff
RSP: 0018:ffffc9000494fc28 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff874c37b2 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000449 R12: 0000000000000000
R13: ffff888027a7b980 R14: ffff888028bc08e0 R15: 1ffff92000929f90
FS: 0000000000000000(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0154d8000 CR3: 000000006fb4b000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 48 89 fa mov %rdi,%rdx
3: 48 c1 ea 03 shr $0x3,%rdx
7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
b: 0f 85 e3 00 00 00 jne 0xf4
11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
18: fc ff df
1b: 48 8b 5b 20 mov 0x20(%rbx),%rbx
1f: 48 8d 7b 08 lea 0x8(%rbx),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 ee 00 00 00 jne 0x122
34: 48 8b 7b 08 mov 0x8(%rbx),%rdi
38: e8 a0 36 1c fa callq 0xfa1c36dd
3d: e8 .byte 0xe8
3e: 8b ff mov %edi,%edi


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[Jakub Kicinski]

Adding TIPC

[Xin Long]

It seems that we should free the lsock after the worker is done:

@@ -699,8 +699,8 @@ static void tipc_topsrv_stop(struct net *net)
__module_get(lsock->sk->sk_prot_creator->owner);
srv->listener = NULL;
spin_unlock_bh(&srv->idr_lock);
- sock_release(lsock);
tipc_topsrv_work_stop(srv);
+ sock_release(lsock);
idr_destroy(&srv->conn_idr);
kfree(srv);