[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.737627] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [ 21.587273] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [ 21.870594] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.901408] random: nonblocking pool is initialized Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts. 2018/05/19 07:07:07 parsed 1 programs 2018/05/19 07:07:07 executed programs: 0 [ 29.109560] IPVS: Creating netns size=2552 id=1 [ 29.292629] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 29.307752] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 29.390963] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 29.408239] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 29.489247] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 29.503809] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 29.521812] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 29.538419] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 30.271570] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 30.310205] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 30.651280] syz-executor0 (4182) used greatest stack depth: 23440 bytes left 2018/05/19 07:07:12 executed programs: 75 [ 34.625827] ------------[ cut here ]------------ [ 34.630586] kernel BUG at fs/ext4/inode.c:2474! [ 34.635226] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 34.641044] Dumping ftrace buffer: [ 34.644554] (ftrace buffer empty) [ 34.648241] Modules linked in: [ 34.651548] CPU: 1 PID: 4533 Comm: syz-executor0 Not tainted 4.4.132-g4f75c34 #41 [ 34.659137] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.668470] task: ffff8801d40b4800 task.stack: ffff8800b5ff0000 [ 34.674500] RIP: 0010:[] [] mpage_prepare_extent_to_map+0x74f/0x970 [ 34.684215] RSP: 0018:ffff8800b5ff73d0 EFLAGS: 00010293 [ 34.689654] RAX: ffff8801d40b4800 RBX: ffffea0002a16640 RCX: 0000000000000000 [ 34.696896] RDX: 0000000000000000 RSI: ffffffff816d736f RDI: ffffea0002a16648 [ 34.704141] RBP: ffff8800b5ff7598 R08: ffff8801d40b5128 R09: 0000000000000001 [ 34.711392] R10: 0000000000000000 R11: ffff8801d40b4800 R12: 0000000000000005 [ 34.718633] R13: 0000000000000000 R14: ffff8800b5ff76e0 R15: dffffc0000000000 [ 34.725875] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 34.734071] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 34.739924] CR2: 000000000814b021 CR3: 00000000bbb55000 CR4: 00000000001606f0 [ 34.747166] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 34.754413] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 34.761656] Stack: [ 34.763784] ffff8800b5ff74f8 1ffff10016bfee8a ffff8800b5ff76e8 ffff8800b5ff7470 [ 34.771781] ffff8800b5ff76f0 00000000b68900e8 ffff8801c7e073d8 000000050000000c [ 34.779758] 7fffffffffffffff ffff8800b5ff74b0 ffff8800b5ff76f8 ffffea0002a16650 [ 34.787778] Call Trace: [ 34.790344] [] ? ext4_journalled_zero_new_buffers+0x350/0x350 [ 34.797852] [] ? __lock_is_held+0xa2/0xf0 [ 34.803625] [] ? rcu_read_lock_sched_held+0x103/0x120 [ 34.810442] [] ? __lock_is_held+0xa2/0xf0 [ 34.816232] [] ext4_writepages+0xbb0/0x2c80 [ 34.822183] [] ? __module_text_address+0x13/0x140 [ 34.828652] [] ? __module_text_address+0x13/0x140 [ 34.835123] [] ? ext4_mark_inode_dirty+0xb80/0xb80 [ 34.841677] [] ? print_context_stack+0x4b/0xd0 [ 34.847885] [] ? dump_trace+0x184/0x360 [ 34.853486] [] ? depot_save_stack+0x1c9/0x610 [ 34.859618] [] ? ext4_mark_inode_dirty+0xb80/0xb80 [ 34.866178] [] do_writepages+0xef/0x1d0 [ 34.871802] [] ? ratelimit_handler+0x50/0x50 [ 34.877868] [] ? do_exit+0x9bf/0x26b0 [ 34.883338] [] ? do_group_exit+0x111/0x330 [ 34.889212] [] ? get_signal+0x4ec/0x14b0 [ 34.894918] [] ? do_signal+0x8b/0x1d30 [ 34.900428] [] ? exit_to_usermode_loop+0x11a/0x160 [ 34.906981] [] ? do_fast_syscall_32+0x620/0x8b0 [ 34.913275] [] ? sysenter_flags_fixed+0xd/0x17 [ 34.919483] [] __filemap_fdatawrite_range+0x1b3/0x250 [ 34.926298] [] ? replace_page_cache_page+0x440/0x440 [ 34.933116] [] ? ext4_check_all_de+0xf0/0xf0 [ 34.939150] [] filemap_flush+0x23/0x30 [ 34.944664] [] ext4_alloc_da_blocks+0x108/0x3c0 [ 34.950972] [] ? ext4_check_all_de+0xf0/0xf0 [ 34.957004] [] ext4_release_file+0x1ff/0x2e0 [ 34.963034] [] __fput+0x235/0x6f0 [ 34.968112] [] ____fput+0x15/0x20 [ 34.973280] [] task_work_run+0x10f/0x190 [ 34.979052] [] do_exit+0x9e5/0x26b0 [ 34.984307] [] ? release_task.part.17+0x1200/0x1200 [ 34.990946] [] ? __lock_acquire+0xa86/0x5270 [ 34.996981] [] ? kasan_slab_free+0x72/0xc0 [ 35.002836] [] ? kmem_cache_free+0xbe/0x340 [ 35.008781] [] ? recalc_sigpending+0x76/0xa0 [ 35.014813] [] do_group_exit+0x111/0x330 [ 35.020497] [] get_signal+0x4ec/0x14b0 [ 35.026016] [] ? fsnotify+0x866/0x10c0 [ 35.031526] [] do_signal+0x8b/0x1d30 [ 35.036872] [] ? __fsnotify_update_child_dentry_flags.part.2+0x300/0x300 [ 35.045344] [] ? selinux_file_permission+0x2f2/0x450 [ 35.052069] [] ? setup_sigcontext+0x780/0x780 [ 35.058187] [] ? rw_verify_area+0x100/0x300 [ 35.064136] [] ? compat_SyS_futex+0x1e1/0x2f0 [ 35.070253] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 35.077239] [] ? exit_to_usermode_loop+0xe4/0x160 [ 35.083705] [] exit_to_usermode_loop+0x11a/0x160 [ 35.090104] [] do_fast_syscall_32+0x620/0x8b0 [ 35.096234] [] sysenter_flags_fixed+0xd/0x17 [ 35.102260] Code: ff 48 8b 75 d0 65 48 33 34 25 28 00 00 00 0f 85 2e 02 00 00 48 81 c4 a0 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 71 9e c7 ff <0f> 0b e8 6a 9e c7 ff 8b 95 18 ff ff ff 85 d2 75 7f e8 5b 9e c7 [ 35.129124] RIP [] mpage_prepare_extent_to_map+0x74f/0x970 [ 35.136494] RSP [ 35.140918] ---[ end trace 11384980df507adb ]--- [ 35.145721] Kernel panic - not syncing: Fatal exception [ 35.151571] Dumping ftrace buffer: [ 35.155086] (ftrace buffer empty) [ 35.158767] Kernel Offset: disabled [ 35.162367] Rebooting in 86400 seconds..