[....] Starting enhanced syslogd: rsyslogd[ 14.316534] audit: type=1400 audit(1558683810.336:4): avc: denied { syslog } for pid=1921 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.50' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 35.415725] ------------[ cut here ]------------ [ 35.420728] kernel BUG at fs/ext4/fsync.c:96! [ 35.420736] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 35.420740] Modules linked in: [ 35.420745] CPU: 0 PID: 2074 Comm: syz-executor707 Not tainted 4.4.174+ #17 [ 35.420749] task: ffff8800b749df00 task.stack: ffff8800b6450000 [ 35.420770] RIP: 0010:[] [] ext4_sync_file+0x930/0xf10 [ 35.420773] RSP: 0018:ffff8801db607aa8 EFLAGS: 00010206 [ 35.420775] RAX: ffff8800b749df00 RBX: ffff8801d6b8d1a0 RCX: dffffc0000000000 [ 35.420778] RDX: 0000000000000100 RSI: ffffffff816359e0 RDI: ffff8800b749ef50 [ 35.420780] RBP: ffff8801db607af8 R08: 0000000000000003 R09: ffff8800b749e810 [ 35.420783] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800b7705600 [ 35.420785] R13: ffff8801d6b8d1c8 R14: 0000000000000000 R15: ffff8801d768a200 [ 35.420789] FS: 0000000000000000(0000) GS:ffff8801db600000(0063) knlGS:0000000008ff3840 [ 35.420791] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 35.420794] CR2: 00007fff9634c0e8 CR3: 00000000b7703000 CR4: 00000000001606b0 [ 35.420798] Stack: [ 35.420803] ffff8800ba2ba000 ffff8801d6b8d278 0000000100000009 000000000000ffff [ 35.420808] 0000000000000000 ffffffff816350b0 ffff8800b7705600 0000000000000001 [ 35.420812] 0000000000000000 000000000000ffff ffff8801db607b48 ffffffff81538fd1 [ 35.420813] Call Trace: [ 35.420820] [ 35.420820] [] ? ext4_llseek+0x970/0x970 [ 35.420827] [] vfs_fsync_range+0x111/0x260 [ 35.420832] [] dio_complete+0x3e6/0x720 [ 35.420836] [] dio_bio_end_aio+0x176/0x3f0 [ 35.420839] [] ? dio_complete+0x720/0x720 [ 35.420845] [] bio_endio+0x187/0x1e0 [ 35.420850] [] blk_update_request+0x267/0xa50 [ 35.420857] [] scsi_end_request+0x9c/0x5d0 [ 35.420861] [] scsi_io_completion+0x275/0x1810 [ 35.420868] [] ? trace_hardirqs_on+0x10/0x10 [ 35.420871] [] ? scsi_unblock_requests+0x50/0x50 [ 35.420877] [] ? virtscsi_complete_cmd+0x800/0x800 [ 35.420883] [] ? kvm_clock_get_cycles+0x9/0x10 [ 35.420887] [] ? scsi_handle_queue_ramp_up+0x32a/0x430 [ 35.420893] [] ? clockevents_program_event+0x1c4/0x3f0 [ 35.420898] [] ? sd_completed_bytes+0x3e0/0x3e0 [ 35.420902] [] scsi_finish_command+0x3a4/0x520 [ 35.420906] [] scsi_softirq_done+0x259/0x370 [ 35.420930] [] ? trace_hardirqs_on_caller+0x260/0x5a0 [ 35.420936] [] blk_done_softirq+0x258/0x3a0 [ 35.420940] [] ? trigger_softirq+0x210/0x210 [ 35.420947] [] __do_softirq+0x226/0xa3f [ 35.420953] [] irq_exit+0x10a/0x150 [ 35.420957] [] do_IRQ+0x111/0x1d0 [ 35.420961] [] common_interrupt+0x9d/0x9d [ 35.420968] [ 35.420969] [] ? debug_lockdep_rcu_enabled.part.0+0x45/0x60 [ 35.420972] [] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 35.420977] [] __radix_tree_lookup+0x12e/0x290 [ 35.420981] [] radix_tree_lookup_slot+0x72/0xc0 [ 35.420985] [] ? __radix_tree_lookup+0x290/0x290 [ 35.420990] [] ? debug_smp_processor_id+0x1c/0x20 [ 35.420996] [] find_get_entry+0x8e/0x340 [ 35.421001] [] ? page_cache_prev_hole+0x80/0x80 [ 35.421005] [] pagecache_get_page+0x48/0x400 [ 35.421009] [] __find_get_block_slow+0x126/0x330 [ 35.421013] [] ? drop_buffers+0x2d0/0x2d0 [ 35.421018] [] ? __might_sleep+0x90/0x1a0 [ 35.421023] [] unmap_underlying_metadata+0x31/0xb0 [ 35.421028] [] ext4_writepages+0x14bf/0x2c40 [ 35.421032] [] ? mempool_alloc+0x156/0x360 [ 35.421037] [] ? ext4_mark_inode_dirty+0xbf0/0xbf0 [ 35.421041] [] ? blk_rq_map_sg+0x402/0xf60 [ 35.421046] [] ? ext4_mark_inode_dirty+0xbf0/0xbf0 [ 35.421050] [] do_writepages+0xfc/0x1e0 [ 35.421054] [] ? ratelimit_handler+0x50/0x50 [ 35.421058] [] ? check_preemption_disabled+0x3c/0x200 [ 35.421061] [] ? check_preemption_disabled+0x3c/0x200 [ 35.421066] [] __filemap_fdatawrite_range+0x1ad/0x260 [ 35.421070] [] ? replace_page_cache_page+0x420/0x420 [ 35.421074] [] ? ext4_mark_iloc_dirty+0x11d0/0x24d0 [ 35.421078] [] ? check_preemption_disabled+0x3c/0x200 [ 35.421081] [] ? check_preemption_disabled+0x3c/0x200 [ 35.421086] [] filemap_flush+0x24/0x30 [ 35.421090] [] ext4_alloc_da_blocks+0x105/0x3d0 [ 35.421096] [] ext4_ind_migrate+0x51e/0x610 [ 35.421101] [] ? __ext4_journal_stop+0xea/0x1c0 [ 35.421104] [] ext4_ioctl+0x2676/0x2cd0 [ 35.421108] [] ? swap_inode_data+0x700/0x700 [ 35.421112] [] ? __lock_acquire+0xa4f/0x4f50 [ 35.421116] [] ? queue_unplugged+0xbb/0x380 [ 35.421122] [] ? selinux_file_ioctl+0x103/0x5b0 [ 35.421126] [] ? trace_hardirqs_on+0xd/0x10 [ 35.421130] [] ? selinux_parse_skb.constprop.0+0x16b0/0x16b0 [ 35.421134] [] ext4_compat_ioctl+0xe0/0x420 [ 35.421137] [] ? ext4_ioctl+0x2cd0/0x2cd0 [ 35.421143] [] ? security_file_ioctl+0x8f/0xc0 [ 35.421147] [] ? ext4_ioctl+0x2cd0/0x2cd0 [ 35.421152] [] compat_SyS_ioctl+0x403/0x2210 [ 35.421157] [] ? compat_SyS_ppoll+0x3d0/0x3d0 [ 35.421161] [] ? SyS_io_destroy+0x350/0x350 [ 35.421165] [] ? vfs_write+0x372/0x4e0 [ 35.421171] [] ? do_fast_syscall_32+0xd6/0xa90 [ 35.421175] [] ? compat_SyS_ppoll+0x3d0/0x3d0 [ 35.421179] [] do_fast_syscall_32+0x32d/0xa90 [ 35.421184] [] sysenter_flags_fixed+0xd/0x1a [ 35.421240] Code: 00 00 49 8b 86 60 fe ff ff 48 0f ba e0 27 0f 82 e7 fe ff ff e8 22 3c cd ff 4c 89 f7 e8 ca 66 eb ff e9 81 fb ff ff e8 10 3c cd ff <0f> 0b e8 09 3c cd ff 65 8b 15 1a 07 9e 7e 48 8b 05 8b 0e 20 01 [ 35.421245] RIP [] ext4_sync_file+0x930/0xf10 [ 35.421246] RSP [ 35.421267] ---[ end trace adc0f74abdaa0bc3 ]--- [ 35.421272] Kernel panic - not syncing: Fatal exception in interrupt [ 35.425671] Kernel Offset: disabled [ 36.070662] Rebooting in 86400 seconds..