------------[ cut here ]------------ kobject: 'loop4' (000000007ea34ab9): kobject_uevent_env kobject: 'loop4' (000000007ea34ab9): fill_kobj_path: path = '/devices/virtual/block/loop4' ODEBUG: free active (active state 1) object type: rcu_head hint: (null) WARNING: CPU: 1 PID: 9052 at lib/debugobjects.c:325 debug_print_object+0x168/0x250 lib/debugobjects.c:325 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 9052 Comm: syz-executor.3 Not tainted 4.19.75 #0 kobject: 'loop2' (00000000c51224d9): kobject_uevent_env 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: 'loop2' (00000000c51224d9): fill_kobj_path: path = '/devices/virtual/block/loop2' audit: type=1800 audit(1569496933.950:58): pid=9060 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="sda1" ino=16690 res=0 __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:debug_print_object+0x168/0x250 lib/debugobjects.c:325 Code: dd 20 56 82 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 20 56 82 87 48 c7 c7 60 4b 82 87 e8 d6 04 19 fe <0f> 0b 83 05 cb 83 17 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3 RSP: 0018:ffff88804f5377f0 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff8155dbd6 RDI: ffffed1009ea6ef0 RBP: ffff88804f537830 R08: ffff888050d262c0 R09: fffffbfff10f2a01 R10: fffffbfff10f2a00 R11: ffffffff88795003 R12: 0000000000000001 R13: ffffffff8879f200 R14: 0000000000000000 R15: ffff88805136f420 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline] debug_check_no_obj_freed+0x29f/0x464 lib/debugobjects.c:817 kmem_cache_free+0x18f/0x260 mm/slab.c:3764 free_task_struct kernel/fork.c:162 [inline] free_task+0xdd/0x120 kernel/fork.c:416 __put_task_struct+0x20f/0x4c0 kernel/fork.c:689 put_task_struct include/linux/sched/task.h:96 [inline] finish_task_switch+0x52b/0x780 kernel/sched/core.c:2710 context_switch kernel/sched/core.c:2829 [inline] __schedule+0x86e/0x1dc0 kernel/sched/core.c:3474 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:3701 retint_kernel+0x1b/0x2d RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:181 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 83 RSP: 0018:ffff88804f537b68 EFLAGS: 00010206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffff88808997ce80 RCX: 0000000000001000 RDX: 0000000000001000 RSI: ffffc90013503000 RDI: ffff88808997ce80 RBP: ffff88804f537b98 R08: ffff888050d262c0 R09: ffff88812c3f0dc0 R10: 0000000000000000 R11: ffff88808997de7f R12: 0000000000001000 R13: 00007ffffffff000 R14: ffffc90013503000 R15: ffff888050d262c0 read_mem+0xfc/0x2c0 drivers/char/mem.c:163 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x490/0x640 fs/read_write.c:925 vfs_readv+0xf0/0x160 fs/read_write.c:987 do_preadv+0x1c4/0x280 fs/read_write.c:1071 __do_sys_preadv fs/read_write.c:1121 [inline] __se_sys_preadv fs/read_write.c:1116 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1116 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459a29 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff3792b9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459a29 RDX: 0000000000000002 RSI: 0000000020000200 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000fffbc000 R11: 0000000000000246 R12: 00007ff3792ba6d4 R13: 00000000004c6d3d R14: 00000000004dc0b8 R15: 00000000ffffffff ======================================================