[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 61.379281][ T26] audit: type=1800 audit(1559934771.303:25): pid=8731 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 61.424045][ T26] audit: type=1800 audit(1559934771.313:26): pid=8731 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 61.474661][ T26] audit: type=1800 audit(1559934771.313:27): pid=8731 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?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 '10.128.10.11' (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 syzkaller login: [ 87.727670][ T3487] ================================================================== [ 87.735939][ T3487] BUG: KASAN: use-after-free in blk_mq_free_rqs+0x49f/0x4b0 [ 87.735956][ T3487] Read of size 8 at addr ffff88808e7fab50 by task kworker/1:2/3487 [ 87.735960][ T3487] [ 87.735983][ T3487] CPU: 1 PID: 3487 Comm: kworker/1:2 Not tainted 5.2.0-rc3+ #22 [ 87.735992][ T3487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 87.736010][ T3487] Workqueue: events __blk_release_queue executing program [ 87.736040][ T3487] Call Trace: [ 87.736064][ T3487] dump_stack+0x172/0x1f0 [ 87.751302][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.751325][ T3487] print_address_description.cold+0x7c/0x20d [ 87.751337][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.751351][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.751374][ T3487] __kasan_report.cold+0x1b/0x40 [ 87.751392][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.761352][ T3487] kasan_report+0x12/0x20 [ 87.761370][ T3487] __asan_report_load8_noabort+0x14/0x20 [ 87.761390][ T3487] blk_mq_free_rqs+0x49f/0x4b0 [ 87.776979][ T3487] ? dd_exit_queue+0x92/0xd0 [ 87.776993][ T3487] ? kfree+0x170/0x220 [ 87.777016][ T3487] blk_mq_sched_tags_teardown+0x126/0x210 [ 87.789585][ T3487] ? dd_request_merge+0x230/0x230 [ 87.789610][ T3487] blk_mq_exit_sched+0x1fa/0x2d0 [ 87.800611][ T3487] elevator_exit+0x70/0xa0 [ 87.800635][ T3487] __blk_release_queue+0x127/0x330 [ 87.810523][ T3487] process_one_work+0x989/0x1790 [ 87.810550][ T3487] ? pwq_dec_nr_in_flight+0x320/0x320 [ 87.819909][ T3487] ? lock_acquire+0x16f/0x3f0 [ 87.819941][ T3487] worker_thread+0x98/0xe40 [ 87.830341][ T3487] ? trace_hardirqs_on+0x67/0x220 [ 87.830369][ T3487] kthread+0x354/0x420 [ 87.839095][ T3487] ? process_one_work+0x1790/0x1790 [ 87.839110][ T3487] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 87.839145][ T3487] ret_from_fork+0x24/0x30 [ 87.849887][ T3487] [ 87.849898][ T3487] Allocated by task 8896: [ 87.849925][ T3487] save_stack+0x23/0x90 [ 87.849938][ T3487] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 87.859385][ T3487] kasan_kmalloc+0x9/0x10 [ 87.859416][ T3487] kmem_cache_alloc_trace+0x151/0x750 [ 87.869597][ T3487] loop_add+0x51/0x8d0 [ 87.869608][ T3487] loop_probe+0x161/0x1a0 [ 87.869622][ T3487] kobj_lookup+0x260/0x460 [ 87.869644][ T3487] get_gendisk+0x4d/0x390 [ 87.875781][ T8898] kobject: 'mq' (0000000098ff2bd6): kobject_uevent_env: filter function caused the event to drop! [ 87.879891][ T3487] __blkdev_get+0x457/0x1660 [ 87.879902][ T3487] blkdev_get+0xc4/0x990 [ 87.879913][ T3487] blkdev_open+0x205/0x290 [ 87.879935][ T3487] do_dentry_open+0x4df/0x1250 [ 87.885157][ T8898] kobject: '0' (00000000da606470): kobject_add_internal: parent: 'mq', set: '' [ 87.889465][ T3487] vfs_open+0xa0/0xd0 [ 87.889482][ T3487] path_openat+0x10e9/0x46d0 [ 87.889500][ T3487] do_filp_open+0x1a1/0x280 [ 87.893712][ T8898] kobject: 'cpu0' (00000000e16020b3): kobject_add_internal: parent: '0', set: '' [ 87.898747][ T3487] do_sys_open+0x3fe/0x5d0 [ 87.898760][ T3487] __x64_sys_open+0x7e/0xc0 [ 87.898775][ T3487] do_syscall_64+0xfd/0x680 [ 87.898790][ T3487] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 87.898795][ T3487] [ 87.898802][ T3487] Freed by task 8897: [ 87.898816][ T3487] save_stack+0x23/0x90 [ 87.898827][ T3487] __kasan_slab_free+0x102/0x150 [ 87.898845][ T3487] kasan_slab_free+0xe/0x10 [ 87.905853][ T8898] kobject: 'cpu1' (00000000ac473b24): kobject_add_internal: parent: '0', set: '' [ 87.909473][ T3487] kfree+0xcf/0x220 [ 87.909486][ T3487] loop_remove+0xa1/0xd0 [ 87.909512][ T3487] loop_control_ioctl+0x320/0x360 [ 87.912019][ T8898] kobject: 'queue' (000000006d2bce03): kobject_uevent_env [ 87.916146][ T3487] do_vfs_ioctl+0xd5f/0x1380 [ 87.916157][ T3487] ksys_ioctl+0xab/0xd0 [ 87.916166][ T3487] __x64_sys_ioctl+0x73/0xb0 [ 87.916181][ T3487] do_syscall_64+0xfd/0x680 [ 87.916196][ T3487] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 87.916201][ T3487] [ 87.916211][ T3487] The buggy address belongs to the object at ffff88808e7fa940 [ 87.916211][ T3487] which belongs to the cache kmalloc-1k of size 1024 [ 87.916232][ T3487] The buggy address is located 528 bytes inside of [ 87.916232][ T3487] 1024-byte region [ffff88808e7fa940, ffff88808e7fad40) [ 87.921023][ T8898] kobject: 'queue' (000000006d2bce03): kobject_uevent_env: filter function caused the event to drop! [ 87.925995][ T3487] The buggy address belongs to the page: [ 87.926010][ T3487] page:ffffea000239fe80 refcount:1 mapcount:0 mapping:ffff8880aa400ac0 index:0x0 compound_mapcount: 0 [ 87.926027][ T3487] flags: 0x1fffc0000010200(slab|head) [ 87.926046][ T3487] raw: 01fffc0000010200 ffffea00022aa108 ffffea00023c2608 ffff8880aa400ac0 [ 87.926062][ T3487] raw: 0000000000000000 ffff88808e7fa040 0000000100000007 0000000000000000 [ 87.926067][ T3487] page dumped because: kasan: bad access detected [ 87.926071][ T3487] [ 87.926074][ T3487] Memory state around the buggy address: [ 87.926085][ T3487] ffff88808e7faa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.926095][ T3487] ffff88808e7faa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.926109][ T3487] >ffff88808e7fab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.931387][ T8898] kobject: 'iosched' (00000000e03301b9): kobject_add_internal: parent: 'queue', set: '' [ 87.935790][ T3487] ^ [ 87.935804][ T3487] ffff88808e7fab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.935814][ T3487] ffff88808e7fac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.935819][ T3487] ================================================================== [ 87.935823][ T3487] Disabling lock debugging due to kernel taint [ 87.936127][ T3487] Kernel panic - not syncing: panic_on_warn set ... [ 87.940239][ T8898] kobject: 'iosched' (00000000e03301b9): kobject_uevent_env [ 87.944275][ T3487] CPU: 1 PID: 3487 Comm: kworker/1:2 Tainted: G B 5.2.0-rc3+ #22 [ 87.944284][ T3487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 87.944306][ T3487] Workqueue: events __blk_release_queue [ 87.944314][ T3487] Call Trace: [ 87.944345][ T3487] dump_stack+0x172/0x1f0 [ 87.948796][ T8898] kobject: 'iosched' (00000000e03301b9): kobject_uevent_env: filter function caused the event to drop! [ 87.953244][ T3487] panic+0x2cb/0x744 [ 87.953271][ T3487] ? __warn_printk+0xf3/0xf3 [ 87.964096][ T8898] kobject: 'integrity' (0000000085a3cfeb): kobject_add_internal: parent: 'loop0', set: '' [ 87.968508][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.968532][ T3487] ? preempt_schedule+0x4b/0x60 [ 87.972905][ T8898] kobject: 'integrity' (0000000085a3cfeb): kobject_uevent_env [ 87.977185][ T3487] ? ___preempt_schedule+0x16/0x18 [ 87.977201][ T3487] ? trace_hardirqs_on+0x5e/0x220 [ 87.977218][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.977239][ T3487] end_report+0x47/0x4f [ 87.982033][ T8898] kobject: 'integrity' (0000000085a3cfeb): kobject_uevent_env: filter function caused the event to drop! [ 87.991436][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.991451][ T3487] __kasan_report.cold+0xe/0x40 [ 87.991465][ T3487] ? blk_mq_free_rqs+0x49f/0x4b0 [ 87.991485][ T3487] kasan_report+0x12/0x20 [ 87.995650][ T8899] kobject: 'integrity' (0000000085a3cfeb): kobject_uevent_env [ 88.000041][ T3487] __asan_report_load8_noabort+0x14/0x20 [ 88.000062][ T3487] blk_mq_free_rqs+0x49f/0x4b0 [ 88.004646][ T8899] kobject: 'integrity' (0000000085a3cfeb): kobject_uevent_env: filter function caused the event to drop! [ 88.014278][ T3487] ? dd_exit_queue+0x92/0xd0 [ 88.014292][ T3487] ? kfree+0x170/0x220 [ 88.014312][ T3487] blk_mq_sched_tags_teardown+0x126/0x210 [ 88.014332][ T3487] ? dd_request_merge+0x230/0x230 [ 88.018848][ T8899] kobject: 'integrity' (0000000085a3cfeb): kobject_cleanup, parent 00000000dbc9e045 [ 88.023237][ T3487] blk_mq_exit_sched+0x1fa/0x2d0 [ 88.023257][ T3487] elevator_exit+0x70/0xa0 [ 88.027823][ T8899] kobject: 'integrity' (0000000085a3cfeb): does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt. [ 88.033634][ T3487] __blk_release_queue+0x127/0x330 [ 88.033659][ T3487] process_one_work+0x989/0x1790 [ 88.036044][ T8899] kobject: 'integrity': free name [ 88.039961][ T3487] ? pwq_dec_nr_in_flight+0x320/0x320 [ 88.040004][ T3487] ? lock_acquire+0x16f/0x3f0 [ 88.524505][ T3487] worker_thread+0x98/0xe40 [ 88.529009][ T3487] ? trace_hardirqs_on+0x67/0x220 [ 88.534246][ T3487] kthread+0x354/0x420 [ 88.538325][ T3487] ? process_one_work+0x1790/0x1790 [ 88.543558][ T3487] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 88.549789][ T3487] ret_from_fork+0x24/0x30 [ 88.555282][ T3487] Kernel Offset: disabled [ 88.559730][ T3487] Rebooting in 86400 seconds..