==================================================================
BUG: KASAN: stack-out-of-bounds in __debug_check_no_obj_freed lib/debugobjects.c:775 [inline]
BUG: KASAN: stack-out-of-bounds in debug_check_no_obj_freed+0x467/0x595 lib/debugobjects.c:815
PANIC: double fault, error_code: 0x0
Read of size 8 at addr ffff8801b18141c0 by task syz-fuzzer/4450
CPU: 1 PID: 11216 Comm: syz-executor0 Not tainted 4.18.0-rc3+ #55

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
CPU: 0 PID: 4450 Comm: syz-fuzzer Not tainted 4.18.0-rc3+ #55
RIP: 0010:__lock_acquire+0x2e/0x5020 kernel/locking/lockdep.c:3294
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Code: 
Call Trace:
41 
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
57 
41 
89 
cf 
41 
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
56 41 
55 
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
49 
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
89 fd 
 __debug_check_no_obj_freed lib/debugobjects.c:775 [inline]
 debug_check_no_obj_freed+0x467/0x595 lib/debugobjects.c:815
41 
54 
45 89 
 kmem_cache_free+0x216/0x2d0 mm/slab.c:3755
cc 
 __sigqueue_free.part.29+0x7d/0xa0 kernel/signal.c:411
53 
 __sigqueue_free kernel/signal.c:407 [inline]
 collect_signal kernel/signal.c:547 [inline]
 __dequeue_signal+0x530/0x7d0 kernel/signal.c:569
65 
4c 
8b 34 
25 
 dequeue_signal+0xbc/0x620 kernel/signal.c:587
40 
ee 
01 
00 48 
83 
e4 f0 
 get_signal+0x3f1/0x1970 kernel/signal.c:2361
48 
81 
ec 60 
03 00 
00 48 
 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
8b 
45 
10 <89> 
94 
24 
80 
00 00 
00 
48 ba 
 exit_to_usermode_loop+0x2e0/0x370 arch/x86/entry/common.c:162
00 
00 
00 
00 
 prepare_exit_to_usermode+0x342/0x3b0 arch/x86/entry/common.c:197
00 
fc 
ff 
df 48 
 retint_user+0x8/0x18
89 84 
RIP: 0033:0x42c0c2
24 
Code: 
98 
01 
48 
RSP: 0018:ffff8801afc9ee60 EFLAGS: 00010086
8b 
5c 
RAX: 0000000000000000 RBX: 1ffff10035f93e48 RCX: 0000000000000002
f7 
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff88f92620
10 
RBP: ffff8801afc9f1e8 R08: 0000000000000000 R09: 0000000000000000
48 
R10: ffff8801b1887be0 R11: ffff8801c677aabb R12: 0000000000000000
8b 
R13: ffffffff88f92620 R14: ffff8801c677a340 R15: 0000000000000002
00 
FS:  0000000001206940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
00 
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
00 
CR2: ffff8801afc9ee58 CR3: 00000001c9ff0000 CR4: 00000000001406e0
00 
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
00 
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
00 
Call Trace:
00