[....] Starting enhanced syslogd: rsyslogd[ 13.488051] audit: type=1400 audit(1516114253.946:5): avc: denied { syslog } for pid=3512 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 syzkaller login: [ 18.460176] audit: type=1400 audit(1516114258.918:6): avc: denied { map } for pid=3651 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 Warning: Permanently added '10.128.0.52' (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 [ 24.696308] audit: type=1400 audit(1516114265.155:7): avc: denied { map } for pid=3665 comm="syzkaller642056" path="/root/syzkaller642056623" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 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 [ 25.254825] ================================================================== [ 25.262239] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 25.268976] Read of size 8 at addr ffff8801d8d11680 by task blkid/3807 [ 25.275611] [ 25.277212] CPU: 0 PID: 3807 Comm: blkid Not tainted 4.15.0-rc7-mm1+ #56 [ 25.284031] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.293369] Call Trace: [ 25.295935] dump_stack+0x194/0x257 [ 25.299539] ? arch_local_irq_restore+0x53/0x53 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 [ 25.304192] ? show_regs_print_info+0x18/0x18 [ 25.308682] ? kfree_const+0x31/0x40 [ 25.312373] ? disk_unblock_events+0x51/0x60 [ 25.316768] print_address_description+0x73/0x250 [ 25.321589] ? disk_unblock_events+0x51/0x60 [ 25.325974] kasan_report+0x23b/0x360 [ 25.329755] __asan_report_load8_noabort+0x14/0x20 [ 25.334660] disk_unblock_events+0x51/0x60 [ 25.338872] __blkdev_get+0x869/0x10e0 [ 25.342746] ? __blkdev_put+0x7f0/0x7f0 [ 25.346707] blkdev_get+0x3a1/0xad0 [ 25.350314] ? bd_link_disk_holder+0x8b0/0x8b0 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 [ 25.354873] ? do_raw_spin_trylock+0x190/0x190 [ 25.359433] ? errseq_sample+0xee/0x140 [ 25.363383] ? _copy_to_user+0xc0/0xc0 [ 25.367254] ? _raw_spin_unlock+0x22/0x30 [ 25.371395] blkdev_open+0x1c9/0x250 [ 25.375084] ? security_file_open+0x89/0x190 [ 25.379479] do_dentry_open+0x667/0xd40 [ 25.383432] ? bd_acquire+0x2c0/0x2c0 [ 25.387227] vfs_open+0x107/0x220 [ 25.390661] path_openat+0x1151/0x3530 [ 25.394539] ? path_lookupat+0xba0/0xba0 [ 25.398577] ? lock_downgrade+0x980/0x980 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 [ 25.402697] ? do_sys_open+0x2e7/0x6d0 [ 25.406567] ? find_held_lock+0x35/0x1d0 [ 25.410608] ? do_raw_spin_trylock+0x190/0x190 [ 25.415169] ? __lock_is_held+0xb6/0x140 [ 25.419216] ? _raw_spin_unlock+0x22/0x30 [ 25.423347] ? __alloc_fd+0x29b/0x750 [ 25.427144] do_filp_open+0x25b/0x3b0 [ 25.430923] ? may_open_dev+0xe0/0xe0 [ 25.434710] ? mpi_resize+0x200/0x200 [ 25.438493] ? get_unused_fd_flags+0x121/0x190 [ 25.443056] ? getname_flags+0x256/0x580 [ 25.447111] do_sys_open+0x502/0x6d0 [ 25.450798] ? do_sys_open+0x502/0x6d0 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 [ 25.454667] ? filp_open+0x70/0x70 [ 25.458192] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 25.463013] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 25.468017] SyS_open+0x2d/0x40 [ 25.471283] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.476013] RIP: 0033:0x7f180dfea120 [ 25.479700] RSP: 002b:00007fff7fac8ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 25.487385] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f180dfea120 [ 25.494629] RDX: 00007fff7fac9f45 RSI: 0000000000000000 RDI: 00007fff7fac9f45 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 [ 25.501873] RBP: 00007fff7fac9f3d R08: 0000000000000078 R09: 0000000000000000 [ 25.509116] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000019da030 [ 25.516361] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000005 [ 25.523630] [ 25.525233] Allocated by task 3791: [ 25.528837] save_stack+0x43/0xd0 [ 25.532273] kasan_kmalloc+0xad/0xe0 [ 25.535970] kmem_cache_alloc_node_trace+0x150/0x750 [ 25.541048] __alloc_disk_node+0xb4/0x4e0 [ 25.545180] loop_add+0x44c/0xa70 [ 25.548611] loop_control_ioctl+0x2e9/0x490 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 [ 25.552914] do_vfs_ioctl+0x1b1/0x1520 [ 25.556783] SyS_ioctl+0x8f/0xc0 [ 25.560127] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.564853] [ 25.566455] Freed by task 3807: [ 25.569711] save_stack+0x43/0xd0 [ 25.573139] __kasan_slab_free+0x11a/0x170 [ 25.577349] kasan_slab_free+0xe/0x10 [ 25.581121] kfree+0xd9/0x260 [ 25.584218] disk_release+0x327/0x410 [ 25.587991] device_release+0x7c/0x210 [ 25.591866] kobject_put+0x14c/0x250 [ 25.595554] put_disk+0x23/0x30 [ 25.598811] __blkdev_get+0x7c9/0x10e0 [ 25.602678] blkdev_get+0x3a1/0xad0 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 [ 25.606291] blkdev_open+0x1c9/0x250 [ 25.609980] do_dentry_open+0x667/0xd40 [ 25.613931] vfs_open+0x107/0x220 [ 25.617357] path_openat+0x1151/0x3530 [ 25.621218] do_filp_open+0x25b/0x3b0 [ 25.624990] do_sys_open+0x502/0x6d0 [ 25.628791] SyS_open+0x2d/0x40 [ 25.632052] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.636778] [ 25.638379] The buggy address belongs to the object at ffff8801d8d11100 [ 25.638379] which belongs to the cache kmalloc-2048 of size 2048 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 [ 25.651199] The buggy address is located 1408 bytes inside of [ 25.651199] 2048-byte region [ffff8801d8d11100, ffff8801d8d11900) [ 25.663220] The buggy address belongs to the page: [ 25.668136] page:ffffea0007634400 count:1 mapcount:0 mapping:ffff8801d8d10000 index:0x0 compound_mapcount: 0 [ 25.678083] flags: 0x2fffc0000008100(slab|head) [ 25.682735] raw: 02fffc0000008100 ffff8801d8d10000 0000000000000000 0000000100000003 [ 25.690590] raw: ffffea0006ed2ea0 ffffea0007669b20 ffff8801dac00c40 0000000000000000 [ 25.698442] page dumped because: kasan: bad access detected [ 25.704133] 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 [ 25.705731] Memory state around the buggy address: [ 25.710633] ffff8801d8d11580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.717986] ffff8801d8d11600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.725494] >ffff8801d8d11680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.732828] ^ [ 25.736177] ffff8801d8d11700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.743508] ffff8801d8d11780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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 [ 25.750839] ================================================================== [ 25.758169] Disabling lock debugging due to kernel taint [ 25.763684] Kernel panic - not syncing: panic_on_warn set ... [ 25.763684] [ 25.771025] CPU: 0 PID: 3807 Comm: blkid Tainted: G B 4.15.0-rc7-mm1+ #56 [ 25.779152] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.788478] Call Trace: [ 25.791040] dump_stack+0x194/0x257 [ 25.794653] ? arch_local_irq_restore+0x53/0x53 [ 25.799295] ? kasan_end_report+0x32/0x50 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 [ 25.803420] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 25.808146] ? vsnprintf+0x1ed/0x1900 [ 25.811919] ? disk_unblock_events+0x20/0x60 [ 25.816302] panic+0x1e4/0x41c [ 25.819472] ? refcount_error_report+0x214/0x214 [ 25.824199] ? add_taint+0x1c/0x50 [ 25.827709] ? add_taint+0x1c/0x50 [ 25.831239] ? disk_unblock_events+0x51/0x60 [ 25.835622] kasan_end_report+0x50/0x50 [ 25.839569] kasan_report+0x148/0x360 [ 25.843350] __asan_report_load8_noabort+0x14/0x20 [ 25.848252] disk_unblock_events+0x51/0x60 [ 25.852461] __blkdev_get+0x869/0x10e0 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 [ 25.856324] ? __blkdev_put+0x7f0/0x7f0 [ 25.860283] blkdev_get+0x3a1/0xad0 [ 25.863895] ? bd_link_disk_holder+0x8b0/0x8b0 [ 25.868451] ? do_raw_spin_trylock+0x190/0x190 [ 25.873005] ? errseq_sample+0xee/0x140 [ 25.876949] ? _copy_to_user+0xc0/0xc0 [ 25.880811] ? _raw_spin_unlock+0x22/0x30 [ 25.884932] blkdev_open+0x1c9/0x250 [ 25.888618] ? security_file_open+0x89/0x190 [ 25.893015] do_dentry_open+0x667/0xd40 [ 25.896978] ? bd_acquire+0x2c0/0x2c0 [ 25.900763] vfs_open+0x107/0x220 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 [ 25.904195] path_openat+0x1151/0x3530 [ 25.908323] ? path_lookupat+0xba0/0xba0 [ 25.912357] ? lock_downgrade+0x980/0x980 [ 25.916475] ? do_sys_open+0x2e7/0x6d0 [ 25.920337] ? find_held_lock+0x35/0x1d0 [ 25.924371] ? do_raw_spin_trylock+0x190/0x190 [ 25.928931] ? __lock_is_held+0xb6/0x140 [ 25.932968] ? _raw_spin_unlock+0x22/0x30 [ 25.937089] ? __alloc_fd+0x29b/0x750 [ 25.940868] do_filp_open+0x25b/0x3b0 [ 25.944644] ? may_open_dev+0xe0/0xe0 [ 25.948421] ? mpi_resize+0x200/0x200 [ 25.952205] ? get_unused_fd_flags+0x121/0x190 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 [ 25.956769] ? getname_flags+0x256/0x580 [ 25.960806] do_sys_open+0x502/0x6d0 [ 25.964491] ? do_sys_open+0x502/0x6d0 [ 25.968353] ? filp_open+0x70/0x70 [ 25.971878] ? entry_SYSCALL_64_fastpath+0x5/0xa0 [ 25.976698] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 25.981691] SyS_open+0x2d/0x40 [ 25.984945] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.989672] RIP: 0033:0x7f180dfea120 [ 25.993355] RSP: 002b:00007fff7fac8ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 26.001034] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f180dfea120 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 26.008279] RDX: 00007fff7fac9f45 RSI: 0000000000000000 RDI: 00007fff7fac9f45 [ 26.015530] RBP: 00007fff7fac9f3d R08: 0000000000000078 R09: 0000000000000000 [ 26.022862] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000019da030 [ 26.030112] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000005 [ 26.037743] Dumping ftrace buffer: [ 26.041260] (ftrace buffer empty) [ 26.044956] Kernel Offset: disabled [ 26.048559] Rebooting in 86400 seconds..