------------[ cut here ]------------
WARNING: CPU: 1 PID: 6602 at kernel/fork.c:677 __put_task_struct.cold+0x29/0x48 kernel/fork.c:677
kobject: 'loop3' (00000000c395618a): kobject_uevent_env
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6602 Comm: syz-executor.4 Not tainted 4.19.75 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x263/0x507 kernel/panic.c:185
kobject: 'loop3' (00000000c395618a): fill_kobj_path: path = '/devices/virtual/block/loop3'
 __warn.cold+0x20/0x4a kernel/panic.c:540
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1037
RIP: 0010:__put_task_struct.cold+0x29/0x48 kernel/fork.c:677
Code: ff e8 20 7d 2c 00 48 c7 c7 20 45 49 87 e8 f8 e3 16 00 0f 0b e9 34 4b ff ff e8 08 7d 2c 00 48 c7 c7 20 45 49 87 e8 e0 e3 16 00 <0f> 0b e9 c5 4a ff ff e8 f0 7c 2c 00 48 c7 c7 20 45 49 87 e8 c8 e3
RSP: 0018:ffff8880a8417cd8 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8155dbd6 RDI: ffffed1015082f8d
RBP: ffff8880a8417d00 R08: 0000000000000024 R09: ffffed1015d25079
R10: ffffed1015d25078 R11: ffff8880ae9283c7 R12: ffff8880878d65c0
R13: ffff888080f20770 R14: 0000000000000000 R15: 0000000000000000
audit: type=1800 audit(1569708259.093:184): pid=6600 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=collect_data cause=failed comm="syz-executor.0" name=7374617409C0D2FEBCF9DF2DEAC8C177FF171248E91193513049F831550D6F7DE66CF637BDBF1311920C8A26EDA4DCC3783F9DB5116B34D31B0512A5608AAFF01E7952340CD6FD dev="sda1" ino=16865 res=0
 put_task_struct include/linux/sched/task.h:96 [inline]
 rdma_restrack_del+0x1da/0x240 drivers/infiniband/core/restrack.c:229
 rdma_destroy_id+0xac/0xab0 drivers/infiniband/core/cma.c:1726
 ucma_close+0x115/0x320 drivers/infiniband/core/ucma.c:1770
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413711
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffcdb2c3830 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413711
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: ffffffffffffffff R09: ffffffffffffffff
R10: 00007ffcdb2c3910 R11: 0000000000000293 R12: 000000000075bfc8
R13: 00000000000d4ea8 R14: 00000000007605d0 R15: 000000000075bfd4
Kernel Offset: disabled
Rebooting in 86400 seconds..