KASAN: stack-out-of-bounds Read in init_rcu_head

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 2bdea157b999 Merge branch 'sctp-fully-support-for-dscp-and..
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16a18058400000
kernel config: https://syzkaller.appspot.com/x/.config?x=f62553dc846b0692
dashboard link: https://syzkaller.appspot.com/bug?extid=0c8d9d5fe8b53e5ecc70
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [je...@linux.vnet.ibm.com linux-...@vger.kernel.org
linux...@vger.kernel.org martin....@oracle.com]

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0c8d9d...@syzkaller.appspotmail.com

PANIC: double fault, error_code: 0x0
CPU: 1 PID: 12635 Comm: syz-executor6 Not tainted 4.18.0-rc3+ #45
==================================================================
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
BUG: KASAN: stack-out-of-bounds in lookup_object lib/debugobjects.c:157
[inline]
BUG: KASAN: stack-out-of-bounds in __debug_object_init+0xe55/0x12e0
lib/debugobjects.c:383
RIP: 0010:__lock_acquire+0x2e/0x5020 kernel/locking/lockdep.c:3294
Read of size 8 at addr ffff8801d8ea8168 by task kworker/0:1H/1817
Code:

41
CPU: 0 PID: 1817 Comm: kworker/0:1H Not tainted 4.18.0-rc3+ #45
57
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
41
Workqueue: kblockd blk_mq_requeue_work
89
cf
Call Trace:
41 56
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
41 55
49
89
fd
41 54
print_address_description+0x6c/0x20b mm/kasan/report.c:256
45 89
cc
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
53
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
65
lookup_object lib/debugobjects.c:157 [inline]
__debug_object_init+0xe55/0x12e0 lib/debugobjects.c:383
4c
8b
34 25
40 ee
01 00
48
83 e4
f0
48 81
ec
60 03
00
00
48 8b
45
10 <89>
94 24
debug_object_init+0x16/0x20 lib/debugobjects.c:429
80
init_rcu_head+0x10/0x20 kernel/rcu/update.c:375
00 00
scsi_initialize_rq drivers/scsi/scsi_lib.c:1191 [inline]
scsi_init_command+0x586/0x7a0 drivers/scsi/scsi_lib.c:1237
00
48
ba 00
00
scsi_mq_prep_fn drivers/scsi/scsi_lib.c:1960 [inline]
scsi_queue_rq+0xfa4/0x1ef0 drivers/scsi/scsi_lib.c:2052
00
00
00
fc ff
df
48 89
84
24 98
RSP: 0018:ffff8801d89ffe20 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 1ffff1003b140040 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff88f92620
RBP: ffff8801d8a001a8 R08: 0000000000000000 R09: 0000000000000000
R10: ffff8801d8f271b8 R11: ffff8801daf236b3 R12: 0000000000000000
R13: ffffffff88f92620 R14: ffff8801ae1f81c0 R15: 0000000000000002
FS: 00007fe058c89700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8801d89ffe18 CR3: 00000001ca091000 CR4: 00000000001406e0
DR0: 00000000200001c0 DR1: 0000000020000080 DR2: 0000000000000000
blk_mq_dispatch_rq_list+0xe12/0x24d0 block/blk-mq.c:1143
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:


---
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[Dmitry Vyukov]

Actually dup of upstream-reported "KASAN: stack-out-of-bounds Read in
timerqueue_add". But I will dedup them in moderation to not spam
upstream:

#syz dup: BUG: unable to handle kernel paging request in ttwu_do_activate

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