Subject: Re: BUG: corrupted list in rxrpc_local_processor

From: syzbot <[email-masked]>
Date: Mon, 12 Aug 2019 03:20:06 -0700

syzbot has found a reproducer for the following crash on:

HEAD commit:    125b7e09 net: tc35815: Explicitly check NET_IP_ALIGN is no..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=16fb7bc2600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4c9e9f08e9e8960
dashboard link: https://syzkaller.appspot.com/bug?extid=193e29e9387ea5837f1d
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=159d4eba600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ba194a600000

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

IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready
list_del corruption. prev->next should be ffff8880996e84e0, but was  
ffff8880996e8960
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:51!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.3.0-rc3+ #159
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: krxrpcd rxrpc_local_processor
RIP: 0010:__list_del_entry_valid.cold+0xf/0x4f lib/list_debug.c:51
Code: e8 e9 03 1e fe 0f 0b 48 89 f1 48 c7 c7 80 25 c6 87 4c 89 e6 e8 d5 03  
1e fe 0f 0b 4c 89 f6 48 c7 c7 20 27 c6 87 e8 c4 03 1e fe <0f> 0b 4c 89 ea  
4c 89 f6 48 c7 c7 60 26 c6 87 e8 b0 03 1e fe 0f 0b
RSP: 0018:ffff8880a9917cc0 EFLAGS: 00010286
RAX: 0000000000000054 RBX: ffff8880996e84f8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815c3b96 RDI: ffffed1015322f8a
RBP: ffff8880a9917cd8 R08: 0000000000000054 R09: ffffed1015d260d1
R10: ffffed1015d260d0 R11: ffff8880ae930687 R12: ffff88808f998638
R13: ffff88808f998638 R14: ffff8880996e84e0 R15: ffff8880aa0a8500
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2648a08db8 CR3: 00000000981a9000 CR4: 00000000001406e0
Call Trace:
  __list_del_entry include/linux/list.h:131 [inline]
  list_del_init include/linux/list.h:190 [inline]
  rxrpc_local_destroyer net/rxrpc/local_object.c:429 [inline]
  rxrpc_local_processor+0x251/0x830 net/rxrpc/local_object.c:465
  process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
  worker_thread+0x98/0xe40 kernel/workqueue.c:2415
  kthread+0x361/0x430 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 4d70382ddfcfe2b8 ]---
RIP: 0010:__list_del_entry_valid.cold+0xf/0x4f lib/list_debug.c:51
Code: e8 e9 03 1e fe 0f 0b 48 89 f1 48 c7 c7 80 25 c6 87 4c 89 e6 e8 d5 03  
1e fe 0f 0b 4c 89 f6 48 c7 c7 20 27 c6 87 e8 c4 03 1e fe <0f> 0b 4c 89 ea  
4c 89 f6 48 c7 c7 60 26 c6 87 e8 b0 03 1e fe 0f 0b
RSP: 0018:ffff8880a9917cc0 EFLAGS: 00010286
RAX: 0000000000000054 RBX: ffff8880996e84f8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815c3b96 RDI: ffffed1015322f8a
RBP: ffff8880a9917cd8 R08: 0000000000000054 R09: ffffed1015d260d1
R10: ffffed1015d260d0 R11: ffff8880ae930687 R12: ffff88808f998638
R13: ffff88808f998638 R14: ffff8880996e84e0 R15: ffff8880aa0a8500
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2648a08db8 CR3: 00000000981a9000 CR4: 00000000001406e0