[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 37.538727] random: sshd: uninitialized urandom read (32 bytes read) [ 37.795309] kauditd_printk_skb: 10 callbacks suppressed [ 37.795317] audit: type=1400 audit(1578768159.674:35): avc: denied { map } for pid=7251 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 37.845780] random: sshd: uninitialized urandom read (32 bytes read) [ 38.495648] random: sshd: uninitialized urandom read (32 bytes read) [ 38.676787] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts. [ 44.215579] random: sshd: uninitialized urandom read (32 bytes read) 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 [ 44.334476] audit: type=1400 audit(1578768166.214:36): avc: denied { map } for pid=7264 comm="syz-executor027" path="/root/syz-executor027477566" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 44.344247] md: md0 stopped. executing program executing program executing program executing program executing program executing program executing program executing program [ 44.383930] md: md0 stopped. [ 44.387985] md: md0 stopped. executing program executing program executing program executing program executing program executing program [ 44.439691] md: md0 stopped. [ 44.444231] md: md0 stopped. executing program executing program executing program [ 44.495523] md: md0 stopped. executing program [ 44.556219] ================================================================== [ 44.563234] md: md0 stopped. [ 44.563702] BUG: KASAN: use-after-free in disk_unblock_events+0x55/0x60 [ 44.573441] Read of size 8 at addr ffff8880a0470a48 by task syz-executor027/7339 [ 44.580958] [ 44.581022] md: md0 stopped. [ 44.582596] CPU: 0 PID: 7339 Comm: syz-executor027 Not tainted 4.14.163-syzkaller #0 [ 44.582601] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.582604] Call Trace: executing program [ 44.582626] dump_stack+0x142/0x197 [ 44.582640] ? disk_unblock_events+0x55/0x60 [ 44.582650] print_address_description.cold+0x7c/0x1dc [ 44.582659] ? disk_unblock_events+0x55/0x60 [ 44.611039] md: md0 stopped. [ 44.613456] kasan_report.cold+0xa9/0x2af [ 44.613469] __asan_report_load8_noabort+0x14/0x20 [ 44.613479] disk_unblock_events+0x55/0x60 [ 44.613489] __blkdev_get+0x7d6/0x1120 [ 44.613502] ? __blkdev_put+0x7f0/0x7f0 [ 44.633865] md: md0 stopped. [ 44.635914] ? bd_acquire+0x178/0x2c0 executing program executing program executing program executing program executing program [ 44.635926] ? find_held_lock+0x35/0x130 [ 44.635937] blkdev_get+0xa8/0x8e0 [ 44.635950] ? bd_may_claim+0xd0/0xd0 [ 44.635961] ? do_raw_spin_unlock+0x16b/0x260 [ 44.635969] ? _raw_spin_unlock+0x2d/0x50 [ 44.635979] blkdev_open+0x1d1/0x260 [ 44.662287] md: md0 stopped. [ 44.662439] ? security_file_open+0x89/0x190 [ 44.669758] md: md0 stopped. [ 44.670708] do_dentry_open+0x73b/0xeb0 [ 44.670719] ? bd_acquire+0x2c0/0x2c0 [ 44.670732] vfs_open+0x105/0x220 [ 44.670743] path_openat+0x8bd/0x3f70 executing program executing program executing program executing program executing program executing program [ 44.670752] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.670764] ? trace_hardirqs_on+0x10/0x10 [ 44.670778] ? path_lookupat.isra.0+0x7b0/0x7b0 [ 44.679724] md: md0 stopped. [ 44.681611] ? __lock_is_held+0xb6/0x140 [ 44.681620] ? save_trace+0x290/0x290 [ 44.681631] ? __alloc_fd+0x1d4/0x4a0 [ 44.681643] do_filp_open+0x18e/0x250 [ 44.681650] ? __alloc_fd+0x1d4/0x4a0 [ 44.681659] ? may_open_dev+0xe0/0xe0 [ 44.681674] ? do_raw_spin_unlock+0x16b/0x260 [ 44.681681] ? _raw_spin_unlock+0x2d/0x50 [ 44.681689] ? __alloc_fd+0x1d4/0x4a0 executing program executing program executing program executing program executing program [ 44.681706] do_sys_open+0x2c5/0x430 [ 44.689766] md: md0 stopped. [ 44.693061] ? filp_open+0x70/0x70 [ 44.693069] ? up_read+0x1a/0x40 [ 44.693077] ? _raw_spin_unlock_irq+0x28/0x90 [ 44.693093] SyS_openat+0x30/0x40 [ 44.693101] ? SyS_open+0x40/0x40 [ 44.693112] do_syscall_64+0x1e8/0x640 [ 44.693120] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.693131] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.693137] RIP: 0033:0x446749 [ 44.693142] RSP: 002b:00007f555978adb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 executing program executing program executing program executing program executing program [ 44.693151] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446749 [ 44.693158] RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c [ 44.701813] md: md0 stopped. [ 44.704160] RBP: 00000000006dbc20 R08: 00007f555978b700 R09: 0000000000000000 [ 44.704165] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 44.704170] R13: 00007ffdd1631adf R14: 00007f555978b9c0 R15: 000000000000002d [ 44.704186] [ 44.704191] Allocated by task 7324: [ 44.704202] save_stack_trace+0x16/0x20 executing program executing program executing program executing program executing program executing program executing program [ 44.704212] save_stack+0x45/0xd0 [ 44.714655] md: md0 stopped. [ 44.718452] kasan_kmalloc+0xce/0xf0 [ 44.718461] kmem_cache_alloc_node_trace+0x153/0x770 [ 44.718470] alloc_disk_node+0x64/0x3e0 [ 44.718477] alloc_disk+0x1b/0x20 [ 44.718483] md_alloc+0x219/0x840 [ 44.718488] md_probe+0x31/0x40 [ 44.718498] kobj_lookup+0x21c/0x400 [ 44.725013] md: md0 stopped. [ 44.725549] get_gendisk+0x3b/0x240 [ 44.725558] __blkdev_get+0x3af/0x1120 [ 44.725564] blkdev_get+0xa8/0x8e0 [ 44.725571] blkdev_open+0x1d1/0x260 executing program executing program [ 44.725579] do_dentry_open+0x73b/0xeb0 [ 44.725585] vfs_open+0x105/0x220 [ 44.725593] path_openat+0x8bd/0x3f70 [ 44.735086] md: md0 stopped. [ 44.736946] do_filp_open+0x18e/0x250 [ 44.736955] do_sys_open+0x2c5/0x430 [ 44.736962] SyS_openat+0x30/0x40 [ 44.736970] do_syscall_64+0x1e8/0x640 [ 44.736978] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.736981] [ 44.736985] Freed by task 7339: [ 44.736993] save_stack_trace+0x16/0x20 [ 44.744679] md: md0 stopped. [ 44.749041] save_stack+0x45/0xd0 [ 44.749048] kasan_slab_free+0x75/0xc0 [ 44.749054] kfree+0xcc/0x270 [ 44.749064] disk_release+0x24b/0x2d0 [ 44.749072] device_release+0xf6/0x1a0 [ 44.749082] kobject_put+0x14e/0x210 [ 44.758101] md: md0 stopped. [ 44.760722] put_disk+0x23/0x30 [ 44.760731] __blkdev_get+0x73c/0x1120 [ 44.760738] blkdev_get+0xa8/0x8e0 [ 44.760745] blkdev_open+0x1d1/0x260 [ 44.760751] do_dentry_open+0x73b/0xeb0 [ 44.760757] vfs_open+0x105/0x220 [ 44.760763] path_openat+0x8bd/0x3f70 [ 44.760769] do_filp_open+0x18e/0x250 [ 44.760775] do_sys_open+0x2c5/0x430 [ 44.760781] SyS_openat+0x30/0x40 [ 44.760788] do_syscall_64+0x1e8/0x640 [ 44.760795] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.760800] [ 44.767471] md: md0 stopped. [ 44.770689] The buggy address belongs to the object at ffff8880a04704c0 [ 44.770689] which belongs to the cache kmalloc-2048 of size 2048 [ 44.770696] The buggy address is located 1416 bytes inside of [ 44.770696] 2048-byte region [ffff8880a04704c0, ffff8880a0470cc0) [ 44.770699] The buggy address belongs to the page: [ 44.770707] page:ffffea0002811c00 count:1 mapcount:0 mapping:ffff8880a04704c0 index:0x0 compound_mapcount: 0 [ 44.770718] flags: 0xfffe0000008100(slab|head) [ 44.770727] raw: 00fffe0000008100 ffff8880a04704c0 0000000000000000 0000000100000003 [ 44.770734] raw: ffffea0002a328a0 ffffea0002811ca0 ffff8880aa800c40 0000000000000000 [ 44.770736] page dumped because: kasan: bad access detected [ 44.770739] [ 44.770742] Memory state around the buggy address: [ 44.770748] ffff8880a0470900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.770753] ffff8880a0470980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.770759] >ffff8880a0470a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.770762] ^ [ 44.770767] ffff8880a0470a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.770772] ffff8880a0470b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.770775] ================================================================== [ 44.770778] Disabling lock debugging due to kernel taint [ 44.776457] Kernel panic - not syncing: panic_on_warn set ... [ 44.776457] [ 44.783280] md: md0 stopped. [ 44.786111] CPU: 0 PID: 7339 Comm: syz-executor027 Tainted: G B 4.14.163-syzkaller #0 [ 44.786116] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.786118] Call Trace: [ 44.786132] dump_stack+0x142/0x197 [ 44.793470] md: md0 stopped. [ 44.796129] ? disk_unblock_events+0x55/0x60 [ 44.796145] panic+0x1f9/0x42d [ 44.804350] md: md0 stopped. [ 44.807010] ? add_taint.cold+0x16/0x16 [ 44.807018] ? ___preempt_schedule+0x16/0x18 [ 44.807029] kasan_end_report+0x47/0x4f [ 44.817169] md: md0 stopped. [ 44.821540] kasan_report.cold+0x130/0x2af [ 44.821548] __asan_report_load8_noabort+0x14/0x20 [ 44.821556] disk_unblock_events+0x55/0x60 [ 44.821563] __blkdev_get+0x7d6/0x1120 [ 44.821571] ? __blkdev_put+0x7f0/0x7f0 [ 44.821579] ? bd_acquire+0x178/0x2c0 [ 44.827397] md: md0 stopped. [ 44.831842] ? find_held_lock+0x35/0x130 [ 44.831850] blkdev_get+0xa8/0x8e0 [ 44.831859] ? bd_may_claim+0xd0/0xd0 [ 44.831866] ? do_raw_spin_unlock+0x16b/0x260 [ 44.831875] ? _raw_spin_unlock+0x2d/0x50 [ 44.842266] md: md0 stopped. [ 44.846392] blkdev_open+0x1d1/0x260 [ 44.846400] ? security_file_open+0x89/0x190 [ 44.846410] do_dentry_open+0x73b/0xeb0 [ 44.851043] md: md0 stopped. [ 44.851643] ? bd_acquire+0x2c0/0x2c0 [ 44.858370] md: md0 stopped. [ 44.859041] vfs_open+0x105/0x220 [ 44.864790] md: md0 stopped. [ 44.865739] path_openat+0x8bd/0x3f70 [ 44.873669] md: md0 stopped. [ 44.874775] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.874784] ? trace_hardirqs_on+0x10/0x10 [ 44.874795] ? path_lookupat.isra.0+0x7b0/0x7b0 [ 44.881185] md: md0 stopped. [ 44.881662] ? __lock_is_held+0xb6/0x140 [ 44.881672] ? save_trace+0x290/0x290 [ 44.887596] md: md0 stopped. [ 44.888645] ? __alloc_fd+0x1d4/0x4a0 [ 44.888653] do_filp_open+0x18e/0x250 [ 44.888661] ? __alloc_fd+0x1d4/0x4a0 [ 44.894394] md: md0 stopped. [ 44.895283] ? may_open_dev+0xe0/0xe0 [ 44.895295] ? do_raw_spin_unlock+0x16b/0x260 [ 44.901939] md: md0 stopped. [ 44.902685] ? _raw_spin_unlock+0x2d/0x50 [ 44.902693] ? __alloc_fd+0x1d4/0x4a0 [ 44.902705] do_sys_open+0x2c5/0x430 [ 44.909399] md: md0 stopped. [ 44.910357] ? filp_open+0x70/0x70 [ 44.910364] ? up_read+0x1a/0x40 [ 44.910372] ? _raw_spin_unlock_irq+0x28/0x90 [ 44.910380] SyS_openat+0x30/0x40 [ 44.910386] ? SyS_open+0x40/0x40 [ 44.910393] do_syscall_64+0x1e8/0x640 [ 44.910402] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.916904] md: md0 stopped. [ 44.917632] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 44.917637] RIP: 0033:0x446749 [ 44.917644] RSP: 002b:00007f555978adb8 EFLAGS: 00000246 [ 44.923677] md: md0 stopped. [ 44.924435] ORIG_RAX: 0000000000000101 [ 44.924440] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446749 [ 44.924444] RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c [ 44.924448] RBP: 00000000006dbc20 R08: 00007f555978b700 R09: 0000000000000000 [ 44.924451] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 44.924455] R13: 00007ffdd1631adf R14: 00007f555978b9c0 R15: 000000000000002d [ 44.929414] Kernel Offset: disabled [ 45.464486] Rebooting in 86400 seconds..