[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 69.266096][ T26] audit: type=1800 audit(1577429179.546:25): pid=9246 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 69.287277][ T26] audit: type=1800 audit(1577429179.556:26): pid=9246 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 69.346187][ T26] audit: type=1800 audit(1577429179.556:27): pid=9246 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?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 '10.128.0.182' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 165.391789][ T9399] ------------[ cut here ]------------ [ 165.397559][ T9399] kernel BUG at fs/buffer.c:3131! [ 165.402709][ T9399] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 165.408817][ T9399] CPU: 0 PID: 9399 Comm: syz-executor863 Not tainted 5.5.0-rc2-next-20191220-syzkaller #0 [ 165.418712][ T9399] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 165.429892][ T9399] RIP: 0010:submit_bh_wbc+0x71c/0x900 [ 165.435245][ T9399] Code: 02 e5 ff f0 80 63 01 f7 e9 ab fa ff ff e8 1c 44 a7 ff 41 81 cd 00 10 00 00 e9 4d fe ff ff e8 0b 44 a7 ff 0f 0b e8 04 44 a7 ff <0f> 0b e8 fd 43 a7 ff 0f 0b e8 f6 43 a7 ff 0f 0b e8 ef 43 a7 ff 0f [ 165.454837][ T9399] RSP: 0018:ffffc90007a07bf8 EFLAGS: 00010293 [ 165.460984][ T9399] RAX: ffff88808c83c340 RBX: ffff8880922e11f8 RCX: ffffffff81ce0b1d [ 165.468952][ T9399] RDX: 0000000000000000 RSI: ffffffff81ce118c RDI: 0000000000000001 [ 165.476910][ T9399] RBP: ffffc90007a07c40 R08: ffff88808c83c340 R09: ffffed101245c240 [ 165.484875][ T9399] R10: ffffed101245c23f R11: ffff8880922e11ff R12: 0000000000000000 [ 165.492870][ T9399] R13: 0000000000000800 R14: 0000000000000001 R15: 0000000000000000 [ 165.500848][ T9399] FS: 0000000001c17940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 165.509775][ T9399] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 165.516354][ T9399] CR2: 00000000006d1090 CR3: 00000000a8590000 CR4: 00000000001406f0 [ 165.524314][ T9399] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 165.532293][ T9399] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 165.540675][ T9399] Call Trace: [ 165.543952][ T9399] __sync_dirty_buffer+0x12b/0x350 [ 165.549059][ T9399] sync_dirty_buffer+0x1b/0x20 [ 165.553822][ T9399] fat_set_state+0x242/0x330 [ 165.558451][ T9399] ? __sync_blockdev+0x88/0xe0 [ 165.563309][ T9399] fat_put_super+0x46/0xd0 [ 165.567722][ T9399] ? fat_statfs+0x4c0/0x4c0 [ 165.572237][ T9399] generic_shutdown_super+0x14c/0x370 [ 165.577601][ T9399] kill_block_super+0xa0/0x100 [ 165.582347][ T9399] deactivate_locked_super+0x95/0x100 [ 165.587701][ T9399] deactivate_super+0x1bd/0x1e0 [ 165.592531][ T9399] ? iterate_supers_type+0x2b0/0x2b0 [ 165.597796][ T9399] ? dput+0x38/0xe10 [ 165.601668][ T9399] ? dput+0x1ed/0xe10 [ 165.605629][ T9399] ? mnt_get_writers.isra.0+0xf9/0x150 [ 165.611084][ T9399] cleanup_mnt+0x351/0x4c0 [ 165.615481][ T9399] ? trace_hardirqs_on+0x67/0x240 [ 165.620484][ T9399] __cleanup_mnt+0x16/0x20 [ 165.624885][ T9399] task_work_run+0x145/0x1c0 [ 165.629475][ T9399] exit_to_usermode_loop+0x316/0x380 [ 165.634782][ T9399] do_syscall_64+0x676/0x790 [ 165.639361][ T9399] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 165.645232][ T9399] RIP: 0033:0x448c07 [ 165.649117][ T9399] Code: 00 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 5d a2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 3d a2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 165.668702][ T9399] RSP: 002b:00007ffe65ab7368 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 [ 165.677105][ T9399] RAX: 0000000000000000 RBX: 000000000002852f RCX: 0000000000448c07 [ 165.685068][ T9399] RDX: 0000000000400c80 RSI: 0000000000000002 RDI: 00007ffe65ab7410 [ 165.693210][ T9399] RBP: 00000000000026ef R08: 0000000000000000 R09: 000000000000000a [ 165.701167][ T9399] R10: 0000000000000005 R11: 0000000000000202 R12: 00007ffe65ab8470 [ 165.709120][ T9399] R13: 0000000001c18940 R14: 0000000000000000 R15: 0000000000000000 [ 165.717099][ T9399] Modules linked in: [ 165.736359][ T9399] ---[ end trace c1d6f8fa36199862 ]--- [ 165.741994][ T9399] RIP: 0010:submit_bh_wbc+0x71c/0x900 [ 165.747382][ T9399] Code: 02 e5 ff f0 80 63 01 f7 e9 ab fa ff ff e8 1c 44 a7 ff 41 81 cd 00 10 00 00 e9 4d fe ff ff e8 0b 44 a7 ff 0f 0b e8 04 44 a7 ff <0f> 0b e8 fd 43 a7 ff 0f 0b e8 f6 43 a7 ff 0f 0b e8 ef 43 a7 ff 0f [ 165.767164][ T9399] RSP: 0018:ffffc90007a07bf8 EFLAGS: 00010293 [ 165.773291][ T9399] RAX: ffff88808c83c340 RBX: ffff8880922e11f8 RCX: ffffffff81ce0b1d [ 165.781372][ T9399] RDX: 0000000000000000 RSI: ffffffff81ce118c RDI: 0000000000000001 [ 165.789371][ T9399] RBP: ffffc90007a07c40 R08: ffff88808c83c340 R09: ffffed101245c240 [ 165.797325][ T9399] R10: ffffed101245c23f R11: ffff8880922e11ff R12: 0000000000000000 [ 165.805326][ T9399] R13: 0000000000000800 R14: 0000000000000001 R15: 0000000000000000 [ 165.813334][ T9399] FS: 0000000001c17940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 165.822328][ T9399] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 165.829038][ T9399] CR2: 0000000002249008 CR3: 00000000a8590000 CR4: 00000000001406f0 [ 165.837007][ T9399] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 165.845018][ T9399] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 165.853049][ T9399] Kernel panic - not syncing: Fatal exception [ 165.860645][ T9399] Kernel Offset: disabled [ 165.864966][ T9399] Rebooting in 86400 seconds..