blk_update_request: I/O error, dev loop2, sector 0
F2FS-fs (loop2): Unable to read 1th superblock
blk_update_request: I/O error, dev loop2, sector 8
F2FS-fs (loop2): Unable to read 2th superblock
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7835 at kernel/events/core.c:1655 perf_group_attach kernel/events/core.c:1655 [inline]
WARNING: CPU: 0 PID: 7835 at kernel/events/core.c:1655 add_event_to_ctx+0x8f3/0xc30 kernel/events/core.c:2229
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7835 Comm: syz-executor.5 Not tainted 4.9.194+ #0
 ffff88019ecdf958 ffffffff81b67001 0000000000000000 ffffffff82a3b3c0
 00000000ffffffff 0000000000000000 0000000000000009 ffff88019ecdfa38
 ffffffff813fef3a 0000000041b58ab3 ffffffff82e32f55 ffffffff813fed61
Call Trace:
 [<000000004a54615a>] __dump_stack lib/dump_stack.c:15 [inline]
 [<000000004a54615a>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<00000000a8b45e0e>] panic+0x1d9/0x3bd kernel/panic.c:180
 [<0000000077a6de61>] __warn.cold+0x2f/0x2f kernel/panic.c:546
 [<00000000ba5d7548>] warn_slowpath_null+0x2d/0x40 kernel/panic.c:589
 [<0000000083be6b5d>] perf_group_attach kernel/events/core.c:1655 [inline]
 [<0000000083be6b5d>] add_event_to_ctx+0x8f3/0xc30 kernel/events/core.c:2229
 [<000000003071f4f6>] __perf_install_in_context+0x282/0x330 kernel/events/core.c:2320
 [<00000000c2f5ed4c>] remote_function kernel/events/core.c:83 [inline]
 [<00000000c2f5ed4c>] remote_function+0x11e/0x1a0 kernel/events/core.c:63
 [<00000000b7f26e05>] generic_exec_single+0x1c4/0x320 kernel/smp.c:141
 [<00000000d1230379>] smp_call_function_single+0x10d/0x380 kernel/smp.c:285
 [<0000000052ba7d77>] cpu_function_call kernel/events/core.c:137 [inline]
 [<0000000052ba7d77>] perf_install_in_context+0x2f9/0x3a0 kernel/events/core.c:2356
 [<00000000b9a0ef71>] SYSC_perf_event_open kernel/events/core.c:10033 [inline]
 [<00000000b9a0ef71>] SyS_perf_event_open+0x1bd3/0x2720 kernel/events/core.c:9674
 [<000000008966eb43>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<00000000313deec4>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..