[....] Starting enhanced syslogd: rsyslogd[ 10.921601] audit: type=1400 audit(1515025586.646:5): avc: denied { syslog } for pid=3311 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: [ 16.693757] audit: type=1400 audit(1515025592.418:6): avc: denied { map } for pid=3451 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 '10.128.15.224' (ECDSA) to the list of known hosts. net.ipv6.conf.syz5.accept_dad = 0 net.ipv6.conf.syz5.router_solicitations = 0 net.ipv6.conf.syz7.accept_dad = 0 net.ipv6.conf.syz7.router_solicitations = 0 [ 27.089632] audit: type=1400 audit(1515025602.814:7): avc: denied { map } for pid=3467 comm="syzkaller181568" path="/root/syzkaller181568074" 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 net.ipv6.conf.syz3.accept_dad = 0 net.ipv6.conf.syz1.accept_dad = 0 net.ipv6.conf.syz1.router_solicitations = 0 net.ipv6.conf.syz3.router_solicitations = 0 net.ipv6.conf.syz2.accept_dad = 0 net.ipv6.conf.syz2.router_solicitations = 0 net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 net.ipv6.conf.syz6.accept_dad = 0 executing program executing program executing program net.ipv6.conf.syz4.accept_dad = 0 net.ipv6.conf.syz6.router_solicitations = 0 executing program executing program net.ipv6.conf.syz4.router_solicitations = 0 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 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 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 [ 31.283123] ================================================================== [ 31.290536] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 31.297275] Read of size 8 at addr ffff8801bb30c600 by task syzkaller181568/4025 [ 31.304790] [ 31.306405] CPU: 0 PID: 4025 Comm: syzkaller181568 Not tainted 4.15.0-rc6-mm1+ #50 [ 31.314092] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.323425] Call Trace: [ 31.326000] dump_stack+0x137/0x198 executing program executing program executing program executing program executing program executing program executing program [ 31.329616] ? disk_unblock_events+0x51/0x60 [ 31.334014] print_address_description+0x73/0x250 [ 31.338848] ? disk_unblock_events+0x51/0x60 [ 31.343242] kasan_report+0x23b/0x360 [ 31.347033] __asan_report_load8_noabort+0x14/0x20 [ 31.351949] disk_unblock_events+0x51/0x60 [ 31.356174] __blkdev_get+0x6e9/0x1140 [ 31.360055] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 31.365249] ? __blkdev_put+0x7c0/0x7c0 [ 31.369210] ? avc_has_perm_noaudit+0x420/0x420 [ 31.373875] blkdev_get+0x32d/0x920 [ 31.377494] ? bdev_evict_inode+0x4f0/0x4f0 [ 31.381800] ? lock_downgrade+0x860/0x860 [ 31.387084] ? bd_acquire+0x27/0x2c0 [ 31.390799] ? fsnotify+0xd20/0xd20 [ 31.394424] ? _raw_spin_unlock+0x22/0x30 [ 31.398566] blkdev_open+0x1c9/0x250 [ 31.402266] ? security_file_open+0x89/0x190 [ 31.406665] do_dentry_open+0x667/0xd40 [ 31.410632] ? bd_acquire+0x2c0/0x2c0 [ 31.414429] vfs_open+0x107/0x220 [ 31.417875] path_openat+0x5a5/0x26e0 [ 31.421655] ? getname_flags+0xcb/0x580 [ 31.425623] ? path_lookupat+0x8b0/0x8b0 [ 31.429671] ? check_noncircular+0x20/0x20 [ 31.433895] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 31.439075] ? check_noncircular+0x20/0x20 [ 31.443291] ? __lock_is_held+0xb6/0x140 [ 31.447352] ? find_held_lock+0x35/0x1e0 [ 31.451404] do_filp_open+0x19d/0x290 [ 31.455190] ? may_open_dev+0xe0/0xe0 [ 31.458992] ? _raw_spin_unlock+0x22/0x30 [ 31.463125] ? __alloc_fd+0x1d7/0x510 [ 31.466929] do_sys_open+0x336/0x4b0 [ 31.470801] ? do_sys_open+0x336/0x4b0 [ 31.474678] ? filp_open+0x70/0x70 [ 31.478204] ? entry_SYSCALL_64_fastpath+0x5/0x9a [ 31.483037] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.488050] SyS_open+0x2d/0x40 [ 31.491323] entry_SYSCALL_64_fastpath+0x23/0x9a [ 31.496057] RIP: 0033:0x401770 [ 31.499236] RSP: 002b:00007ffe0dd66288 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 31.506928] RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000000401770 [ 31.514181] RDX: 0000000000000000 RSI: 0000000000044042 RDI: 00007ffe0dd66330 [ 31.521431] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 31.528683] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000079bf [ 31.535935] R13: 0000000000402950 R14: 0000000000000000 R15: 0000000000000000 [ 31.543211] [ 31.544822] Allocated by task 4029: [ 31.548431] save_stack+0x43/0xd0 [ 31.551854] kasan_kmalloc+0xad/0xe0 [ 31.555536] kmem_cache_alloc_node_trace+0x150/0x750 [ 31.560611] __alloc_disk_node+0x69/0x3e0 [ 31.564729] loop_add+0x3e3/0x990 [ 31.568158] loop_probe+0x146/0x170 [ 31.571755] kobj_lookup+0x2ac/0x410 [ 31.575443] get_gendisk+0x37/0x2c0 [ 31.579039] __blkdev_get+0x3ce/0x1140 [ 31.582895] blkdev_get+0x32d/0x920 [ 31.586492] blkdev_open+0x1c9/0x250 [ 31.590172] do_dentry_open+0x667/0xd40 [ 31.594112] vfs_open+0x107/0x220 [ 31.597540] path_openat+0x5a5/0x26e0 [ 31.601315] do_filp_open+0x19d/0x290 [ 31.605082] do_sys_open+0x336/0x4b0 [ 31.608771] SyS_open+0x2d/0x40 [ 31.612028] entry_SYSCALL_64_fastpath+0x23/0x9a [ 31.616756] [ 31.618353] Freed by task 4025: [ 31.621598] save_stack+0x43/0xd0 [ 31.625023] __kasan_slab_free+0x11a/0x170 [ 31.629231] kasan_slab_free+0xe/0x10 [ 31.632997] kfree+0xd9/0x260 [ 31.636081] disk_release+0x251/0x2d0 [ 31.639857] device_release+0x7c/0x210 [ 31.643715] kobject_put+0x14c/0x250 [ 31.647400] put_disk+0x23/0x30 [ 31.650645] __blkdev_get+0x649/0x1140 [ 31.654498] blkdev_get+0x32d/0x920 [ 31.658103] blkdev_open+0x1c9/0x250 [ 31.661789] do_dentry_open+0x667/0xd40 [ 31.665736] vfs_open+0x107/0x220 [ 31.669156] path_openat+0x5a5/0x26e0 [ 31.672920] do_filp_open+0x19d/0x290 [ 31.676685] do_sys_open+0x336/0x4b0 [ 31.680363] SyS_open+0x2d/0x40 [ 31.683608] entry_SYSCALL_64_fastpath+0x23/0x9a [ 31.688328] [ 31.689926] The buggy address belongs to the object at ffff8801bb30c080 [ 31.689926] which belongs to the cache kmalloc-2048 of size 2048 [ 31.702727] The buggy address is located 1408 bytes inside of [ 31.702727] 2048-byte region [ffff8801bb30c080, ffff8801bb30c880) [ 31.714741] The buggy address belongs to the page: [ 31.719634] page:ffffea0006ecc300 count:1 mapcount:0 mapping:ffff8801bb30c080 index:0x0 compound_mapcount: 0 [ 31.729570] flags: 0x2fffc0000008100(slab|head) [ 31.734212] raw: 02fffc0000008100 ffff8801bb30c080 0000000000000000 0000000100000003 [ 31.742061] raw: ffffea0007396ba0 ffffea0006ecc3a0 ffff8801db000c40 0000000000000000 [ 31.751554] page dumped because: kasan: bad access detected [ 31.757227] [ 31.758823] Memory state around the buggy address: [ 31.763716] ffff8801bb30c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.771043] ffff8801bb30c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.778367] >ffff8801bb30c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.785690] ^ [ 31.789027] ffff8801bb30c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.796358] ffff8801bb30c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.803680] ================================================================== [ 31.811004] Disabling lock debugging due to kernel taint [ 31.816555] Kernel panic - not syncing: panic_on_warn set ... [ 31.816555] [ 31.823896] CPU: 0 PID: 4025 Comm: syzkaller181568 Tainted: G B 4.15.0-rc6-mm1+ #50 [ 31.832878] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.842207] Call Trace: [ 31.845178] dump_stack+0x137/0x198 [ 31.849644] ? del_gendisk+0x8b0/0x910 [ 31.854106] panic+0x1e4/0x41c [ 31.857265] ? refcount_error_report+0x214/0x214 [ 31.861991] ? add_taint+0x1c/0x50 [ 31.865505] ? add_taint+0x1c/0x50 [ 31.869018] ? disk_unblock_events+0x51/0x60 [ 31.873398] kasan_end_report+0x50/0x50 [ 31.877338] kasan_report+0x148/0x360 [ 31.881105] __asan_report_load8_noabort+0x14/0x20 [ 31.885998] disk_unblock_events+0x51/0x60 [ 31.890207] __blkdev_get+0x6e9/0x1140 [ 31.894064] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 31.899223] ? __blkdev_put+0x7c0/0x7c0 [ 31.903168] ? avc_has_perm_noaudit+0x420/0x420 [ 31.909030] blkdev_get+0x32d/0x920 [ 31.913338] ? bdev_evict_inode+0x4f0/0x4f0 [ 31.917627] ? lock_downgrade+0x860/0x860 [ 31.921740] ? bd_acquire+0x27/0x2c0 [ 31.925423] ? fsnotify+0xd20/0xd20 [ 31.929023] ? _raw_spin_unlock+0x22/0x30 [ 31.933145] blkdev_open+0x1c9/0x250 [ 31.936833] ? security_file_open+0x89/0x190 [ 31.941208] do_dentry_open+0x667/0xd40 [ 31.945148] ? bd_acquire+0x2c0/0x2c0 [ 31.948923] vfs_open+0x107/0x220 [ 31.952345] path_openat+0x5a5/0x26e0 [ 31.956463] ? getname_flags+0xcb/0x580 [ 31.960409] ? path_lookupat+0x8b0/0x8b0 [ 31.964439] ? check_noncircular+0x20/0x20 [ 31.968640] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 31.973803] ? check_noncircular+0x20/0x20 [ 31.978012] ? __lock_is_held+0xb6/0x140 [ 31.982047] ? find_held_lock+0x35/0x1e0 [ 31.986079] do_filp_open+0x19d/0x290 [ 31.989854] ? may_open_dev+0xe0/0xe0 [ 31.993638] ? _raw_spin_unlock+0x22/0x30 [ 31.997761] ? __alloc_fd+0x1d7/0x510 [ 32.001530] do_sys_open+0x336/0x4b0 [ 32.005211] ? do_sys_open+0x336/0x4b0 [ 32.009065] ? filp_open+0x70/0x70 [ 32.012569] ? entry_SYSCALL_64_fastpath+0x5/0x9a [ 32.017377] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.022360] SyS_open+0x2d/0x40 [ 32.026650] entry_SYSCALL_64_fastpath+0x23/0x9a [ 32.031977] RIP: 0033:0x401770 [ 32.035131] RSP: 002b:00007ffe0dd66288 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 32.042805] RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000000401770 [ 32.050041] RDX: 0000000000000000 RSI: 0000000000044042 RDI: 00007ffe0dd66330 [ 32.057275] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 32.065381] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000079bf [ 32.072620] R13: 0000000000402950 R14: 0000000000000000 R15: 0000000000000000 [ 32.080431] Dumping ftrace buffer: [ 32.083935] (ftrace buffer empty) [ 32.087611] Kernel Offset: disabled [ 32.091203] Rebooting in 86400 seconds..