audit: type=1326 audit(1571174871.439:1212839): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=16004 comm="syz-executor.3" exe="/root/syz-executor.3" sig=0 arch=c000003e syscall=202 compat=0 ip=0x459a59 code=0x50000 audit: type=1326 audit(1571174871.439:1212841): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13228 comm="syz-executor.3" exe="/root/syz-executor.3" sig=0 arch=c000003e syscall=202 compat=0 ip=0x459a59 code=0x50000 ------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 19725 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline] WARNING: CPU: 0 PID: 19725 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151 Kernel panic - not syncing: panic_on_warn set ... kobject: 'loop4' (00000000c6461ae9): kobject_uevent_env CPU: 0 PID: 19725 Comm: syz-executor.0 Not tainted 4.19.79 #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: 'loop4' (00000000c6461ae9): fill_kobj_path: path = '/devices/virtual/block/loop4' __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:refcount_inc_checked lib/refcount.c:153 [inline] RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:151 Code: 1d fe 0b 13 06 31 ff 89 de e8 3b 8b 46 fe 84 db 75 dd e8 f2 89 46 fe 48 c7 c7 a0 2d 82 87 c6 05 de 0b 13 06 01 e8 2d 02 1a fe <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 RSP: 0018:ffff88804cc178b8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000008c30 RSI: ffffffff8155f4a6 RDI: ffffed1009982f09 RBP: ffff88804cc178c8 R08: ffff88807a47a0c0 R09: ffffed1015d03ee3 R10: ffffed1015d03ee2 R11: ffff8880ae81f717 R12: ffff8880a88ad128 R13: 0000000000000000 R14: ffff88809283f2c0 R15: ffff8880928019e8 kref_get include/linux/kref.h:47 [inline] kobject_get+0x66/0xc0 lib/kobject.c:613 cdev_get+0x60/0xb0 fs/char_dev.c:364 chrdev_open+0xb0/0x6b0 fs/char_dev.c:409 do_dentry_open+0x4c3/0x1210 fs/open.c:796 vfs_open+0xa0/0xd0 fs/open.c:905 do_last fs/namei.c:3418 [inline] path_openat+0x10d7/0x45e0 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x550 fs/open.c:1088 __do_sys_open fs/open.c:1106 [inline] __se_sys_open fs/open.c:1101 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1101 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413941 Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fcb194c67a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000413941 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fcb194c6850 RBP: 000000000075bf20 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fcb194c76d4 R13: 00000000004c9086 R14: 00000000004e0548 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds..