Re: [syzbot] BUG: unable to handle kernel NULL pointer dereference in nci_send_cmd

[Lin Ma]

> From: syzbot <syzbot+4adf5ff0f6e6876c6a81@xxxxxxxxxxxxxxxxxxxxxxxxx>
> Sent Time: 2022-11-16 18:52:37 (Wednesday)
> To: davem@xxxxxxxxxxxxx, edumazet@xxxxxxxxxx, krzysztof.kozlowski@xxxxxxxxxx, kuba@xxxxxxxxxx, linma@xxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, pabeni@xxxxxxxxxx, syzkaller-bugs@xxxxxxxxxxxxxxxx
> Cc: 
> Subject: [syzbot] BUG: unable to handle kernel NULL pointer dereference in nci_send_cmd
> 
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    81e7cfa3a9eb Merge tag 'erofs-for-6.1-rc6-fixes' of git://..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=13b7800d880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a2318f9a4fc31ad
> dashboard link: https://syzkaller.appspot.com/bug?extid=4adf5ff0f6e6876c6a81
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11f435be880000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1134d295880000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/54f7533927a5/disk-81e7cfa3.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f3861072b476/vmlinux-81e7cfa3.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/c36747ab66fe/bzImage-81e7cfa3.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+4adf5ff0f6e6876c6a81@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> CPU: 0 PID: 3636 Comm: syz-executor551 Not tainted 6.1.0-rc5-syzkaller-00015-g81e7cfa3a9eb #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
> RIP: 0010:__queue_work+0x1f6/0x13b0 kernel/workqueue.c:1459
> Code: ff ff 48 89 c3 e8 2a 6b 2e 00 4c 89 e7 e8 f2 59 ff ff 48 85 c0 49 89 c5 0f 84 57 01 00 00 e8 11 6b 2e 00 48 89 d8 48 c1 e8 03 <80> 3c 28 00 0f 85 4a 10 00 00 4c 39 2b 0f 84 51 01 00 00 e8 f2 6a
> RSP: 0018:ffffc90003dff388 EFLAGS: 00010056
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff888020e2ba80 RSI: ffffffff8151ae6f RDI: 0000000000000001
> RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff888020a890f8
> R13: ffff888012069800 R14: ffff888021d5d800 R15: ffff888021d5d800
> FS:  00007f11539a4700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f1153a55390 CR3: 0000000077b28000 CR4: 0000000000350ef0
> Call Trace:
>  <TASK>
>  queue_work_on+0xf2/0x110 kernel/workqueue.c:1545
>  queue_work include/linux/workqueue.h:503 [inline]
>  nci_send_cmd+0x247/0x340 net/nfc/nci/core.c:1376
>  nci_reset_req+0x76/0xa0 net/nfc/nci/core.c:166
>  __nci_request+0x87/0x280 net/nfc/nci/core.c:107
>  nci_open_device net/nfc/nci/core.c:502 [inline]
>  nci_dev_up+0x2af/0x670 net/nfc/nci/core.c:631
>  nfc_dev_up+0x1aa/0x3b0 net/nfc/core.c:118
>  nfc_genl_dev_up+0xa6/0xf0 net/nfc/netlink.c:770
>  genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:756
>  genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
>  genl_rcv_msg+0x445/0x780 net/netlink/genetlink.c:850
>  netlink_rcv_skb+0x157/0x430 net/netlink/af_netlink.c:2540
>  genl_rcv+0x28/0x40 net/netlink/genetlink.c:861
>  netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
>  netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1345
>  netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1921
>  sock_sendmsg_nosec net/socket.c:714 [inline]
>  sock_sendmsg+0xd3/0x120 net/socket.c:734
>  ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482
>  ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
>  __sys_sendmsg+0xf7/0x1c0 net/socket.c:2565
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f1153a142f9
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f11539a4318 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00007f1153a9d438 RCX: 00007f1153a142f9
> RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000004
> RBP: 00007f1153a9d430 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000008 R11: 0000000000000246 R12: 00007f1153a6a134
> R13: 00007ffc4c3309cf R14: 00007f11539a4400 R15: 0000000000022000
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:__queue_work+0x1f6/0x13b0 kernel/workqueue.c:1459
> Code: ff ff 48 89 c3 e8 2a 6b 2e 00 4c 89 e7 e8 f2 59 ff ff 48 85 c0 49 89 c5 0f 84 57 01 00 00 e8 11 6b 2e 00 48 89 d8 48 c1 e8 03 <80> 3c 28 00 0f 85 4a 10 00 00 4c 39 2b 0f 84 51 01 00 00 e8 f2 6a
> RSP: 0018:ffffc90003dff388 EFLAGS: 00010056
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff888020e2ba80 RSI: ffffffff8151ae6f RDI: 0000000000000001
> RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff888020a890f8
> R13: ffff888012069800 R14: ffff888021d5d800 R15: ffff888021d5d800
> FS:  00007f11539a4700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f1153a55390 CR3: 0000000077b28000 CR4: 0000000000350ef0
> ----------------
> Code disassembly (best guess), 1 bytes skipped:
>    0:	ff 48 89             	decl   -0x77(%rax)
>    3:	c3                   	retq
>    4:	e8 2a 6b 2e 00       	callq  0x2e6b33
>    9:	4c 89 e7             	mov    %r12,%rdi
>    c:	e8 f2 59 ff ff       	callq  0xffff5a03
>   11:	48 85 c0             	test   %rax,%rax
>   14:	49 89 c5             	mov    %rax,%r13
>   17:	0f 84 57 01 00 00    	je     0x174
>   1d:	e8 11 6b 2e 00       	callq  0x2e6b33
>   22:	48 89 d8             	mov    %rbx,%rax
>   25:	48 c1 e8 03          	shr    $0x3,%rax
> * 29:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1) <-- trapping instruction
>   2d:	0f 85 4a 10 00 00    	jne    0x107d
>   33:	4c 39 2b             	cmp    %r13,(%rbx)
>   36:	0f 84 51 01 00 00    	je     0x18d
>   3c:	e8                   	.byte 0xe8
>   3d:	f2                   	repnz
>   3e:	6a                   	.byte 0x6a
> 
> 
> ---
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> 
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#syz test: https://github.com/f0rm2l1n/linux-fix.git master