audit: type=1400 audit(1602406706.189:8): avc: denied { execmem } for pid=6491 comm="syz-executor140" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue INFO: task syz-executor140:6492 blocked for more than 140 seconds. Not tainted 4.19.150-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor140 D26152 6492 6491 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x8e5/0x22e0 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 io_schedule+0xb5/0x120 kernel/sched/core.c:5185 bit_wait_io+0x12/0x90 kernel/sched/wait_bit.c:207 __wait_on_bit_lock+0xb5/0x170 kernel/sched/wait_bit.c:89 out_of_line_wait_on_bit_lock+0xd2/0x100 kernel/sched/wait_bit.c:116 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline] __lock_buffer+0x52/0x60 fs/buffer.c:65 lock_buffer include/linux/buffer_head.h:374 [inline] __sync_dirty_buffer+0x2a6/0x320 fs/buffer.c:3194 __ext4_handle_dirty_metadata+0x234/0x650 fs/ext4/ext4_jbd2.c:300 ext4_convert_inline_data_nolock+0x5c9/0xd30 fs/ext4/inline.c:1240 ext4_convert_inline_data+0x347/0x39d fs/ext4/inline.c:2026 ext4_fallocate+0x13b/0x2130 fs/ext4/extents.c:4960 vfs_fallocate+0x487/0x9a0 fs/open.c:308 ksys_fallocate fs/open.c:331 [inline] __do_sys_fallocate fs/open.c:339 [inline] __se_sys_fallocate fs/open.c:337 [inline] __x64_sys_fallocate+0xcf/0x140 fs/open.c:337 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x445489 Code: Bad RIP value. RSP: 002b:00007ffc17228468 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445489 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006d1018 R08: 0000000000000001 R09: 0000000000000001 R10: 000000000000ffe0 R11: 0000000000000246 R12: 00000000004025f0 R13: 0000000000402680 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1094: #0: 000000008dc44be5 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x291 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6231: #0: 000000003312ed9f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 2 locks held by syz-executor140/6492: #0: 000000006bc7431b (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2780 [inline] #0: 000000006bc7431b (sb_writers#3){.+.+}, at: vfs_fallocate+0x7c0/0x9a0 fs/open.c:307 #1: 00000000a4d6796d (&ei->xattr_sem){++++}, at: ext4_write_lock_xattr fs/ext4/xattr.h:141 [inline] #1: 00000000a4d6796d (&ei->xattr_sem){++++}, at: ext4_convert_inline_data+0x20a/0x39d fs/ext4/inline.c:2024 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1094 Comm: khungtaskd Not tainted 4.19.150-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+0x22c/0x33e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x18/0x3d lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb 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+0xa62/0x1020 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: 55 Comm: kworker/u4:2 Not tainted 4.19.150-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__lock_acquire+0x1b9/0x3ff0 kernel/locking/lockdep.c:3321 Code: c0 0f 84 14 04 00 00 49 8d b8 38 01 00 00 be 04 00 00 00 4c 89 44 24 18 e8 c4 6b 53 00 4c 8b 44 24 18 f0 41 ff 80 38 01 00 00 <49> 8d 86 80 08 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 c1 48 89 RSP: 0018:ffff8880a9197170 EFLAGS: 00000006 RAX: fffffbfff19c5dea RBX: 0000000000000000 RCX: ffffffff8157a06c RDX: fffffbfff19c5dea RSI: 0000000000000004 RDI: ffffffff8ce2ef48 RBP: 0000000000000000 R08: ffffffff8ce2ee10 R09: fffffbfff19c5de9 R10: ffffffff8ce2ef4b R11: 0000000000000003 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880a917e700 R15: ffff8880a2d91580 FS: 0000000000000000(0000) GS:ffff8880ae200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006d2080 CR3: 0000000084930000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3907 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x90/0xe0 kernel/locking/spinlock.c:152 __set_page_dirty_nobuffers+0x109/0x690 mm/page-writeback.c:2474 redirty_page_for_writepage+0x37/0x60 mm/page-writeback.c:2529 __block_write_full_page+0x7b0/0xff0 fs/buffer.c:1757 block_write_full_page+0x202/0x270 fs/buffer.c:2967 __writepage+0x5e/0xe0 mm/page-writeback.c:2305 write_cache_pages+0x83b/0x13d0 mm/page-writeback.c:2240 generic_writepages mm/page-writeback.c:2329 [inline] generic_writepages+0xdb/0x150 mm/page-writeback.c:2318 do_writepages+0xe5/0x290 mm/page-writeback.c:2344 __writeback_single_inode+0x113/0x13e0 fs/fs-writeback.c:1382 writeback_sb_inodes+0x537/0xf10 fs/fs-writeback.c:1646 __writeback_inodes_wb+0xc6/0x280 fs/fs-writeback.c:1715 wb_writeback+0x841/0xd20 fs/fs-writeback.c:1821 wb_check_old_data_flush fs/fs-writeback.c:1923 [inline] wb_do_writeback fs/fs-writeback.c:1976 [inline] wb_workfn+0x924/0x1230 fs/fs-writeback.c:2005 process_one_work+0x796/0x14e0 kernel/workqueue.c:2155 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415