Re: [syzbot] BUG: corrupted list in nfc_llcp_register_device

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    2475bf0250de Merge tag 'sched_urgent_for_v6.2_rc6' of git:..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=116dd0ac480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=23330449ad10b66f
dashboard link: https://syzkaller.appspot.com/bug?extid=c1d0a03d305972dbbe14
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15e4a789480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=100108fa480000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c1d0a03d305972dbbe14@xxxxxxxxxxxxxxxxxxxxxxxxx

list_add corruption. prev->next should be next (ffff88802620c000), but was ffff88801d633000. (prev=ffffffff8e546e60).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:30!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 12187 Comm: syz-executor209 Not tainted 6.2.0-rc5-syzkaller-00013-g2475bf0250de #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:__list_add_valid.cold+0x56/0x58 lib/list_debug.c:30
Code: 0b 48 89 f2 4c 89 e1 48 89 ee 48 c7 c7 c0 bc a6 8a e8 df 2c f0 ff 0f 0b 48 89 f1 48 c7 c7 40 bc a6 8a 4c 89 e6 e8 cb 2c f0 ff <0f> 0b 4c 89 e1 48 89 ee 48 c7 c7 a0 be a6 8a e8 b7 2c f0 ff 0f 0b
RSP: 0018:ffffc90026c577f0 EFLAGS: 00010282
RAX: 0000000000000075 RBX: ffff888026209000 RCX: 0000000000000000
RDX: ffff888012c20000 RSI: ffffffff816680ec RDI: fffff52004d8aef0
RBP: ffff888026209000 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: ffff88802620c000
R13: ffff88802620c000 R14: 0000000000000000 R15: ffff88802620a140
FS:  0000000000000000(0000) GS:ffff88802c600000(0063) knlGS:0000000057a07380
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000200003c0 CR3: 000000002433d000 CR4: 0000000000150ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_add include/linux/list.h:69 [inline]
 list_add include/linux/list.h:88 [inline]
 nfc_llcp_register_device+0x7a8/0x9e0 net/nfc/llcp_core.c:1604
 nfc_register_device+0x70/0x3b0 net/nfc/core.c:1124
 nci_register_device+0x7cb/0xb50 net/nfc/nci/core.c:1257
 virtual_ncidev_open+0x14f/0x230 drivers/nfc/virtual_ncidev.c:148
 misc_open+0x37a/0x4a0 drivers/char/misc.c:165
 chrdev_open+0x26a/0x770 fs/char_dev.c:414
 do_dentry_open+0x6cc/0x13f0 fs/open.c:882
 do_open fs/namei.c:3557 [inline]
 path_openat+0x1bbc/0x2a50 fs/namei.c:3714
 do_filp_open+0x1ba/0x410 fs/namei.c:3741
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_compat_sys_openat fs/open.c:1386 [inline]
 __se_compat_sys_openat fs/open.c:1384 [inline]
 __ia32_compat_sys_openat+0x143/0x1f0 fs/open.c:1384
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82
RIP: 0023:0xf7e6f549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000ff98601c EFLAGS: 00000292 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 0000000020000080
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 00000000ffffffff
RBP: 0000000000008933 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid.cold+0x56/0x58 lib/list_debug.c:30
Code: 0b 48 89 f2 4c 89 e1 48 89 ee 48 c7 c7 c0 bc a6 8a e8 df 2c f0 ff 0f 0b 48 89 f1 48 c7 c7 40 bc a6 8a 4c 89 e6 e8 cb 2c f0 ff <0f> 0b 4c 89 e1 48 89 ee 48 c7 c7 a0 be a6 8a e8 b7 2c f0 ff 0f 0b
RSP: 0018:ffffc90026c577f0 EFLAGS: 00010282
RAX: 0000000000000075 RBX: ffff888026209000 RCX: 0000000000000000
RDX: ffff888012c20000 RSI: ffffffff816680ec RDI: fffff52004d8aef0
RBP: ffff888026209000 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: ffff88802620c000
R13: ffff88802620c000 R14: 0000000000000000 R15: ffff88802620a140
FS:  0000000000000000(0000) GS:ffff88802c600000(0063) knlGS:0000000057a07380
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000200003c0 CR3: 000000002433d000 CR4: 0000000000150ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	03 74 c0 01          	add    0x1(%rax,%rax,8),%esi
   4:	10 05 03 74 b8 01    	adc    %al,0x1b87403(%rip)        # 0x1b8740d
   a:	10 06                	adc    %al,(%rsi)
   c:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
  10:	10 07                	adc    %al,(%rdi)
  12:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
  16:	10 08                	adc    %cl,(%rax)
  18:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1c:	00 00                	add    %al,(%rax)
  1e:	00 00                	add    %al,(%rax)
  20:	00 51 52             	add    %dl,0x52(%rcx)
  23:	55                   	push   %rbp
  24:	89 e5                	mov    %esp,%ebp
  26:	0f 34                	sysenter
  28:	cd 80                	int    $0x80
* 2a:	5d                   	pop    %rbp <-- trapping instruction
  2b:	5a                   	pop    %rdx
  2c:	59                   	pop    %rcx
  2d:	c3                   	retq
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  39:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi