[....] Starting enhanced syslogd: rsyslogd[ 14.484955] audit: type=1400 audit(1541059161.325:4): avc: denied { syslog } for pid=1916 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 Warning: Permanently added '10.128.10.26' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program 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: [ 58.309432] ================================================================== [ 58.316825] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 58.323560] Read of size 8 at addr ffff8801d8bb40e8 by task blkid/2856 [ 58.330205] [ 58.331816] CPU: 0 PID: 2856 Comm: blkid Not tainted 4.4.162+ #7 [ 58.337938] 0000000000000000 4ee4f871fea24ecd ffff8801d749f6d0 ffffffff81a994bd [ 58.345926] ffffea000762ec00 ffff8801d8bb40e8 0000000000000000 ffff8801d8bb40e8 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.353999] 0000000000000000 ffff8801d749f708 ffffffff8148a669 ffff8801d8bb40e8 [ 58.362008] Call Trace: [ 58.364580] [] dump_stack+0xc1/0x124 [ 58.370022] [] print_address_description+0x6c/0x217 [ 58.376683] [] kasan_report.cold.6+0x175/0x2f7 [ 58.382902] [] ? disk_unblock_events+0x51/0x60 [ 58.389126] [] __asan_report_load8_noabort+0x14/0x20 [ 58.395870] [] disk_unblock_events+0x51/0x60 [ 58.401916] [] __blkdev_get+0x70c/0xdf0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.407530] [] ? trace_hardirqs_on+0x10/0x10 [ 58.413574] [] ? __blkdev_put+0x840/0x840 [ 58.419356] [] ? avc_has_perm_noaudit+0x197/0x2f0 [ 58.425833] [] ? avc_has_perm_noaudit+0x90/0x2f0 [ 58.432227] [] ? fsnotify+0x866/0x10c0 [ 58.437804] [] blkdev_get+0x2da/0x920 [ 58.443249] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 58.449986] [] ? bd_may_claim+0xd0/0xd0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.455594] [] ? bd_acquire+0x29/0x370 [ 58.461115] [] ? bd_acquire+0x8a/0x370 [ 58.466645] [] ? _raw_spin_unlock+0x2c/0x50 [ 58.472600] [] blkdev_open+0x1a5/0x250 [ 58.478125] [] do_dentry_open+0x38d/0xbd0 [ 58.483909] [] ? __inode_permission2+0x9b/0x240 [ 58.490215] [] ? blkdev_get_by_dev+0x70/0x70 [ 58.496263] [] vfs_open+0x12a/0x210 [ 58.501528] [] ? may_open.isra.18+0x156/0x240 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.507657] [] path_openat+0x50c/0x39a0 [ 58.513272] [] ? may_open.isra.18+0x240/0x240 [ 58.519397] [] ? getname+0x19/0x20 [ 58.524564] [] ? do_sys_open+0x203/0x610 [ 58.530250] [] ? SyS_open+0x2d/0x40 [ 58.535512] [] ? entry_SYSCALL_64_fastpath+0x1e/0x9a [ 58.542254] [] ? trace_hardirqs_on+0x10/0x10 [ 58.548300] [] do_filp_open+0x197/0x270 [ 58.553904] [] ? user_path_mountpoint_at+0x70/0x70 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.560466] [] ? __alloc_fd+0x36/0x4a0 [ 58.565992] [] ? _raw_spin_unlock+0x2c/0x50 [ 58.571944] [] ? __alloc_fd+0x1f3/0x4a0 [ 58.577545] [] do_sys_open+0x31c/0x610 [ 58.583057] [] ? filp_open+0x70/0x70 [ 58.588401] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 58.595226] [] SyS_open+0x2d/0x40 [ 58.600317] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 58.606874] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.608482] Allocated by task 2834: [ 58.612079] [] save_stack_trace+0x26/0x50 [ 58.617984] [] kasan_kmalloc.part.1+0x62/0xf0 [ 58.624230] [] kasan_kmalloc+0xaf/0xc0 [ 58.629863] [] kmem_cache_alloc_trace+0x117/0x2d0 [ 58.636459] [] alloc_disk_node+0x54/0x3a0 [ 58.642367] [] alloc_disk+0x18/0x20 [ 58.647748] [] loop_add+0x36b/0x7c0 [ 58.653132] [] loop_probe+0x14f/0x180 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.658679] [] kobj_lookup+0x223/0x410 [ 58.664307] [] get_gendisk+0x39/0x2d0 [ 58.669911] [] __blkdev_get+0x39c/0xdf0 [ 58.675701] [] blkdev_get+0x488/0x920 [ 58.681269] [] blkdev_open+0x1a5/0x250 [ 58.686965] [] do_dentry_open+0x38d/0xbd0 [ 58.692885] [] vfs_open+0x12a/0x210 [ 58.698268] [] path_openat+0x50c/0x39a0 [ 58.703992] [] do_filp_open+0x197/0x270 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 58.709717] [] do_sys_open+0x31c/0x610 [ 58.715360] [] compat_SyS_open+0x2a/0x40 [ 58.721176] [] do_fast_syscall_32+0x31e/0xa80 [ 58.727432] [] sysenter_flags_fixed+0xd/0x1a [ 58.733599] [ 58.735206] Freed by task 2856: [ 58.738455] [] save_stack_trace+0x26/0x50 [ 58.744540] [] kasan_slab_free+0xac/0x190 [ 58.754919] [] kfree+0xf4/0x310 executing program executing program executing program executing program executing program executing program executing program [ 58.760071] [] disk_release+0x259/0x330 [ 58.765807] [] device_release+0x7e/0x220 [ 58.771622] [] kobject_put+0x144/0x260 [ 58.777262] [] put_disk+0x23/0x30 [ 58.782462] [] __blkdev_get+0x66c/0xdf0 [ 58.788191] [] blkdev_get+0x2da/0x920 [ 58.793746] [] blkdev_open+0x1a5/0x250 [ 58.799387] [] do_dentry_open+0x38d/0xbd0 [ 58.805297] [] vfs_open+0x12a/0x210 [ 58.810684] [] path_openat+0x50c/0x39a0 [ 58.816416] [] do_filp_open+0x197/0x270 [ 58.822147] [] do_sys_open+0x31c/0x610 [ 58.827792] [] SyS_open+0x2d/0x40 [ 58.833115] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 58.839878] [ 58.841497] The buggy address belongs to the object at ffff8801d8bb3b80 [ 58.841497] which belongs to the cache kmalloc-2048 of size 2048 [ 58.854313] The buggy address is located 1384 bytes inside of [ 58.854313] 2048-byte region [ffff8801d8bb3b80, ffff8801d8bb4380) [ 58.866340] The buggy address belongs to the page: [ 58.871721] kasan: CONFIG_KASAN_INLINE enabled [ 58.876138] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 58.889279] Modules linked in: [ 58.892588] CPU: 1 PID: 3312 Comm: syz-executor516 Not tainted 4.4.162+ #7 [ 58.899651] task: ffff8800b1b3df00 task.stack: ffff8800b1b68000 [ 58.905690] RIP: 0010:[] [] debug_object_deactivate+0x191/0x340 [ 58.915201] RSP: 0018:ffff8801db707ce0 EFLAGS: 00010002 [ 58.920806] RAX: dffffc0000000000 RBX: 4000000000004080 RCX: 0800000000000813 [ 58.928059] RDX: 1ffffffff080e713 RSI: ffffffff82eafea0 RDI: 4000000000004098 [ 58.935385] RBP: ffff8801db707da0 R08: ffff8800b1b3e810 R09: 000000000010a002 [ 58.942641] R10: ffff8800b1b3df00 R11: 0000000000000001 R12: 1ffff1003b6e0f9e [ 58.949983] R13: ffffffff84073888 R14: ffff8800b6487d28 R15: 0000000000000003 [ 58.957234] FS: 0000000000000000(0000) GS:ffff8801db700000(0063) knlGS:000000000958e840 [ 58.965436] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 58.971295] CR2: 00000000080bfdda CR3: 00000000b906d000 CR4: 00000000001606b0 [ 58.978546] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 58.985795] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 58.993066] Stack: [ 58.995192] 0000000000000096 ffffffff82eafea0 0000000041b58ab3 ffffffff82c5f17d [ 59.003287] ffffffff81af8e90 0000000000000046 0000000000000000 ffffffff8125ccbd [ 59.011404] ffff880000000000 0000000000000000 dffffc0000000000 ffff8800b1b3e7c0 [ 59.019420] Call Trace: [ 59.021979] [ 59.024022] [] ? debug_object_activate+0x480/0x480 [ 59.030876] [] ? __hrtimer_run_queues+0x3ed/0xfc0 [ 59.037348] [] __hrtimer_run_queues+0x215/0xfc0 [ 59.043667] [] ? hrtimer_fixup_init+0x70/0x70 [ 59.049789] [] ? kvm_clock_read+0x23/0x40 [ 59.055559] [] ? kvm_clock_get_cycles+0x9/0x10 [ 59.061767] [] ? hrtimer_interrupt+0x12d/0x430 [ 59.068078] [] hrtimer_interrupt+0x1b1/0x430 [ 59.074126] [] local_apic_timer_interrupt+0x74/0xa0 [ 59.080893] [] smp_apic_timer_interrupt+0x7c/0xa0 [ 59.087360] [] apic_timer_interrupt+0x9d/0xb0 [ 59.093606] [ 59.095649] [] ? _raw_spin_unlock_irqrestore+0x5f/0x70 [ 59.102934] [] __wake_up_sync_key+0x4b/0x60 [ 59.109014] [] pipe_write+0x8e8/0xd80 [ 59.114442] [] __vfs_write+0x304/0x3e0 [ 59.119952] [] ? __vfs_read+0x3d0/0x3d0 [ 59.125616] [] ? selinux_file_permission+0x2f2/0x450 [ 59.132350] [] ? rw_verify_area+0x100/0x2f0 [ 59.138298] [] vfs_write+0x17e/0x4e0 [ 59.143640] [] SyS_write+0xd9/0x1c0 [ 59.148894] [] ? SyS_read+0x1c0/0x1c0 [ 59.154323] [] ? do_fast_syscall_32+0xdb/0xa80 [ 59.160528] [] ? SyS_read+0x1c0/0x1c0 [ 59.165954] [] do_fast_syscall_32+0x31e/0xa80 [ 59.172102] [] sysenter_flags_fixed+0xd/0x1a [ 59.178131] Code: a9 01 00 00 48 8b 1b 41 bf 01 00 00 00 48 85 db 74 42 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 18 41 83 c7 01 48 89 f9 48 c1 e9 03 <80> 3c 01 00 0f 85 0c 01 00 00 4c 3b 73 18 74 7d 48 89 d9 48 c1 [ 59.205153] RIP [] debug_object_deactivate+0x191/0x340 [ 59.212287] RSP [ 59.216059] ---[ end trace e932fce4da9a1a5c ]--- [ 59.220784] Kernel panic - not syncing: Fatal exception in interrupt [ 60.367914] Shutting down cpus with NMI [ 60.372591] Kernel Offset: disabled [ 60.376222] Rebooting in 86400 seconds..