[ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.199' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 40.057990] audit: type=1400 audit(1597410135.144:8): avc: denied { execmem } for pid=6463 comm="syz-executor941" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 40.088827] ------------[ cut here ]------------ [ 40.093722] generic_make_request: Trying to write to read-only block-device loop0 (partno 0) [ 40.103358] WARNING: CPU: 1 PID: 6467 at block/blk-core.c:2180 generic_make_request_checks+0x17d9/0x22e0 [ 40.113021] Kernel panic - not syncing: panic_on_warn set ... [ 40.113021] [ 40.120421] CPU: 1 PID: 6467 Comm: syz-executor941 Not tainted 4.19.139-syzkaller #0 [ 40.128324] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.137682] Call Trace: [ 40.140284] dump_stack+0x1fc/0x2fe [ 40.143935] panic+0x26a/0x50e [ 40.147148] ? __warn_printk+0xf3/0xf3 [ 40.151045] ? generic_make_request_checks+0x17d9/0x22e0 [ 40.156506] ? __probe_kernel_read+0x16c/0x1b0 [ 40.161094] ? __warn.cold+0x5/0x61 [ 40.164722] ? __warn+0xe4/0x200 [ 40.168098] ? generic_make_request_checks+0x17d9/0x22e0 [ 40.173561] __warn.cold+0x20/0x61 [ 40.177111] ? io_schedule_timeout+0x140/0x140 [ 40.181703] ? generic_make_request_checks+0x17d9/0x22e0 [ 40.187192] report_bug+0x262/0x2b0 [ 40.190855] do_error_trap+0x1d7/0x310 [ 40.194758] ? math_error+0x310/0x310 [ 40.198576] ? __irq_work_queue_local+0x101/0x160 [ 40.203436] ? irq_work_queue+0x29/0x80 [ 40.207424] ? wake_up_klogd.part.0+0x8c/0xc0 [ 40.211967] ? trace_hardirqs_off_caller+0x69/0x210 [ 40.217003] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.221871] invalid_op+0x14/0x20 [ 40.225344] RIP: 0010:generic_make_request_checks+0x17d9/0x22e0 [ 40.231413] Code: ca 0a 00 00 45 8b b6 e4 04 00 00 48 8d 74 24 68 48 89 ef e8 99 41 06 00 48 c7 c7 00 56 c9 87 48 89 c6 44 89 f2 e8 62 66 f3 fd <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 [ 40.250329] RSP: 0018:ffff88808ba2f0a8 EFLAGS: 00010286 [ 40.255699] RAX: 0000000000000000 RBX: ffff8880a3ff3000 RCX: 0000000000000000 [ 40.262980] RDX: 0000000000000000 RSI: ffffffff8154cf41 RDI: ffffed1011745e07 [ 40.270289] RBP: ffff88809e43d640 R08: 0000000000000001 R09: 0000000000000000 [ 40.277570] R10: 0000000000000005 R11: 0000000000000000 R12: ffff88809e43d670 [ 40.284862] R13: ffff88809e43d648 R14: 0000000000000000 R15: 0000000000000000 [ 40.292173] ? vprintk_func+0x81/0x17e [ 40.296076] ? generic_make_request_checks+0x17d9/0x22e0 [ 40.301576] ? should_fail_bio.isra.0+0xa0/0xa0 [ 40.306257] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 40.311288] ? kmem_cache_alloc+0x315/0x370 [ 40.315630] generic_make_request+0x23f/0xdf0 [ 40.320141] ? blk_put_request+0x110/0x110 [ 40.324389] ? sb_mark_inode_writeback+0xc8/0x490 [ 40.329260] submit_bio+0xb1/0x430 [ 40.332819] ? generic_make_request+0xdf0/0xdf0 [ 40.337502] ? check_preemption_disabled+0x41/0x280 [ 40.342536] ? guard_bio_eod+0x426/0x640 [ 40.346612] submit_bh_wbc+0x5a7/0x760 [ 40.350517] __block_write_full_page+0x71a/0xf60 [ 40.355292] ? block_llseek+0xc0/0xc0 [ 40.359108] block_write_full_page+0x202/0x270 [ 40.363725] ? block_llseek+0xc0/0xc0 [ 40.367542] __writepage+0x5e/0xe0 [ 40.371101] write_cache_pages+0x802/0x12d0 [ 40.375453] ? tag_pages_for_writeback+0x2f0/0x2f0 [ 40.380414] ? clear_page_dirty_for_io+0xee0/0xee0 [ 40.385389] ? __lock_acquire+0x6de/0x3ff0 [ 40.389650] ? __lock_acquire+0x6de/0x3ff0 [ 40.393921] ? blkdev_readpages+0x30/0x30 [ 40.398085] generic_writepages+0xdb/0x150 [ 40.402344] ? dirty_poll_interval.part.0+0x30/0x30 [ 40.407379] ? mark_held_locks+0xf0/0xf0 [ 40.411469] do_writepages+0xe5/0x290 [ 40.415299] ? page_writeback_cpu_online+0x10/0x10 [ 40.420251] ? do_raw_spin_unlock+0x171/0x230 [ 40.424759] ? _raw_spin_unlock+0x29/0x40 [ 40.428933] ? wbc_attach_and_unlock_inode+0x11d/0x9e0 [ 40.434238] __filemap_fdatawrite_range+0x27d/0x350 [ 40.439281] ? delete_from_page_cache_batch+0xcc0/0xcc0 [ 40.444676] ? lock_downgrade+0x720/0x720 [ 40.448830] ? locks_remove_file+0x2c8/0x450 [ 40.453285] ? blkdev_put+0x30/0x520 [ 40.457015] filemap_write_and_wait+0x42/0xd0 [ 40.461531] __blkdev_put+0x1bb/0x7b0 [ 40.465342] ? fsync_bdev+0xc0/0xc0 [ 40.468974] ? locks_remove_file+0x2cd/0x450 [ 40.473393] ? blkdev_put+0x85/0x520 [ 40.477116] ? blkdev_put+0x520/0x520 [ 40.480926] blkdev_close+0x86/0xb0 [ 40.484559] __fput+0x2ce/0x890 [ 40.487853] task_work_run+0x148/0x1c0 [ 40.491750] do_exit+0xbb2/0x2b70 [ 40.495209] ? futex_wake+0x159/0x480 [ 40.499017] ? mm_update_next_owner+0x650/0x650 [ 40.503701] ? get_signal+0x388/0x1f70 [ 40.507611] ? lock_downgrade+0x720/0x720 [ 40.511780] ? lock_acquire+0x170/0x3c0 [ 40.515787] do_group_exit+0x125/0x310 [ 40.519685] get_signal+0x3f2/0x1f70 [ 40.523420] do_signal+0x8f/0x1670 [ 40.527000] ? setup_sigcontext+0x820/0x820 [ 40.531327] ? vm_mmap_pgoff+0x1c0/0x200 [ 40.535399] ? vm_mmap_pgoff+0xe8/0x200 [ 40.539397] ? vma_is_stack_for_current+0xc0/0xc0 [ 40.544257] ? do_dup2+0x450/0x450 [ 40.547810] ? __se_sys_futex+0x28f/0x3b0 [ 40.551966] ? __se_sys_futex+0x298/0x3b0 [ 40.556143] ? do_futex+0x1c40/0x1c40 [ 40.559957] ? exit_to_usermode_loop+0x36/0x2a0 [ 40.564637] exit_to_usermode_loop+0x204/0x2a0 [ 40.569234] do_syscall_64+0x538/0x620 [ 40.573134] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.578335] RIP: 0033:0x449dd9 [ 40.581545] Code: Bad RIP value. [ 40.584916] RSP: 002b:00007f597200bcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 40.592655] RAX: 0000000000000001 RBX: 00000000006dbc58 RCX: 0000000000449dd9 [ 40.599955] RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000006dbc5c [ 40.607249] RBP: 00000000006dbc50 R08: 0000000000000000 R09: 0000000000000000 [ 40.614524] R10: 0000000000000008 R11: 0000000000000246 R12: 00000000006dbc5c [ 40.621823] R13: 00007ffd0df5168f R14: 00007f597200c9c0 R15: 20c49ba5e353f7cf [ 40.630435] Kernel Offset: disabled [ 40.634137] Rebooting in 86400 seconds..