INFO: task syz-executor197:8094 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor197 D26960 8094 8092 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 fuse_wait_on_page_writeback fs/fuse/file.c:383 [inline] fuse_wait_on_page_writeback.isra.0+0x11b/0x170 fs/fuse/file.c:379 fuse_launder_page fs/fuse/file.c:2033 [inline] fuse_launder_page+0xb6/0xe0 fs/fuse/file.c:2026 do_launder_page mm/truncate.c:655 [inline] invalidate_inode_pages2_range+0x795/0x1110 mm/truncate.c:725 fuse_finish_open+0x2e2/0x590 fs/fuse/file.c:182 fuse_open_common+0x254/0x2c0 fs/fuse/file.c:222 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fcafc4b44c9 Code: Bad RIP value. RSP: 002b:00007fcafc4652f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fcafc5454c0 RCX: 00007fcafc4b44c9 RDX: 0000000000000000 RSI: 0000000000000700 RDI: 0000000020000100 RBP: 00007fcafc512164 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 00007fcafc50e158 R14: 00007fcafc510160 R15: 00007fcafc5454c8 Showing all locks held in the system: 1 lock held by khungtaskd/1571: #0: 0000000075482f13 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 2 locks held by syz-executor197/8094: #0: 000000008accee1c (sb_writers#11){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000008accee1c (sb_writers#11){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360 #1: 00000000043dda49 (&sb->s_type->i_mutex_key#17){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #1: 00000000043dda49 (&sb->s_type->i_mutex_key#17){+.+.}, at: fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1571 Comm: khungtaskd Not tainted 4.19.211-syzkaller #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+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4692 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline] RIP: 0010:trace_hardirqs_off+0x31/0x200 kernel/trace/trace_preemptirq.c:39 Code: 53 e8 03 d8 fa ff 65 8b 1d bc be 9a 7e 31 ff 89 de e8 63 d9 fa ff 85 db 75 3e e8 ea d7 fa ff 65 c7 05 9f be 9a 7e 01 00 00 00 <65> 8b 1d b8 31 9a 7e 81 e3 00 00 10 00 31 ff 89 de e8 39 d9 fa ff RSP: 0018:ffff8880a0f4f9c8 EFLAGS: 00000093 RAX: ffff8880a0f42580 RBX: 0000000000000000 RCX: ffffffff8167ad7d RDX: 0000000000000000 RSI: ffffffff8167ad86 RDI: 0000000000000005 RBP: 00000000006080c0 R08: ffffffff8cd233c0 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000059dfbda2 R12: 0000000000200000 R13: ffff88813bff04c0 R14: 0000000000000048 R15: ffff88813bff04c0 FS: 00007f82f79aa8c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f82f4d7a000 CR3: 00000000a0c59000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: slab_alloc mm/slab.c:3388 [inline] kmem_cache_alloc_trace+0x9b/0x380 mm/slab.c:3623 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] aa_alloc_file_ctx security/apparmor/include/file.h:60 [inline] apparmor_file_alloc_security+0x394/0xad0 security/apparmor/lsm.c:438 security_file_alloc+0x40/0x90 security/security.c:880 __alloc_file+0xd8/0x340 fs/file_table.c:105 alloc_empty_file+0x6d/0x170 fs/file_table.c:150 path_openat+0xe9/0x2df0 fs/namei.c:3526 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f82f6f39840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffd59447788 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffd59447a90 RCX: 00007f82f6f39840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005611df387680 RBP: 000000000000000d R08: 00000000000001c0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 00005611df37b040 R14: 00007ffd59447a50 R15: 00005611df3876d0 ---------------- Code disassembly (best guess): 0: 53 push %rbx 1: e8 03 d8 fa ff callq 0xfffad809 6: 65 8b 1d bc be 9a 7e mov %gs:0x7e9abebc(%rip),%ebx # 0x7e9abec9 d: 31 ff xor %edi,%edi f: 89 de mov %ebx,%esi 11: e8 63 d9 fa ff callq 0xfffad979 16: 85 db test %ebx,%ebx 18: 75 3e jne 0x58 1a: e8 ea d7 fa ff callq 0xfffad809 1f: 65 c7 05 9f be 9a 7e movl $0x1,%gs:0x7e9abe9f(%rip) # 0x7e9abec9 26: 01 00 00 00 * 2a: 65 8b 1d b8 31 9a 7e mov %gs:0x7e9a31b8(%rip),%ebx # 0x7e9a31e9 <-- trapping instruction 31: 81 e3 00 00 10 00 and $0x100000,%ebx 37: 31 ff xor %edi,%edi 39: 89 de mov %ebx,%esi 3b: e8 39 d9 fa ff callq 0xfffad979