[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 61.007483][ T24] audit: type=1800 audit(1560077404.452:25): pid=8739 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 61.050757][ T24] audit: type=1800 audit(1560077404.462:26): pid=8739 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 61.107388][ T24] audit: type=1800 audit(1560077404.462:27): pid=8739 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 '10.128.0.25' (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 syzkaller login: [ 71.843245][ T22] ================================================================== [ 71.851621][ T22] BUG: KASAN: use-after-free in blk_mq_free_rqs+0x49f/0x4b0 [ 71.851642][ T22] Read of size 8 at addr ffff8880a3ab58d0 by task kworker/1:1/22 [ 71.866791][ T22] [ 71.866816][ T22] CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.2.0-rc3-next-20190607 #11 [ 71.866824][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.866849][ T22] Workqueue: events __blk_release_queue [ 71.866876][ T22] Call Trace: [ 71.866931][ T22] dump_stack+0x172/0x1f0 [ 71.866954][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 71.877946][ T22] print_address_description.cold+0xd4/0x306 [ 71.877974][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 71.877986][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 71.877999][ T22] __kasan_report.cold+0x1b/0x36 [ 71.878014][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 71.878028][ T22] kasan_report+0x12/0x20 [ 71.878052][ T22] __asan_report_load8_noabort+0x14/0x20 [ 71.893703][ T22] blk_mq_free_rqs+0x49f/0x4b0 [ 71.893734][ T22] ? dd_exit_queue+0x92/0xd0 [ 71.893747][ T22] ? kfree+0x1ec/0x2a0 [ 71.893770][ T22] blk_mq_sched_tags_teardown+0x126/0x210 [ 71.893790][ T22] ? dd_request_merge+0x230/0x230 [ 71.906937][ T22] blk_mq_exit_sched+0x1fa/0x2d0 [ 71.917908][ T22] elevator_exit+0x70/0xa0 [ 71.917929][ T22] __blk_release_queue+0x127/0x330 [ 71.917999][ T22] process_one_work+0x989/0x1790 [ 71.927872][ T22] ? pwq_dec_nr_in_flight+0x320/0x320 [ 71.927909][ T22] ? lock_acquire+0x16f/0x3f0 [ 71.927932][ T22] worker_thread+0x98/0xe40 [ 71.937255][ T22] kthread+0x354/0x420 [ 71.937278][ T22] ? process_one_work+0x1790/0x1790 [ 71.943831][ T8905] kobject: 'loop0' (0000000095a40d0f): kobject_uevent_env [ 71.947772][ T22] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 71.947811][ T22] ret_from_fork+0x24/0x30 [ 71.947830][ T22] [ 71.953087][ T8905] kobject: 'loop0' (0000000095a40d0f): fill_kobj_path: path = '/devices/virtual/block/loop0' [ 71.956491][ T22] Allocated by task 8903: [ 71.956515][ T22] save_stack+0x23/0x90 [ 71.956535][ T22] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 71.969983][ T8905] kobject: 'queue' (00000000b06b5a19): kobject_add_internal: parent: 'loop0', set: '' [ 71.972208][ T22] kasan_kmalloc+0x9/0x10 [ 71.972221][ T22] kmem_cache_alloc_trace+0x151/0x750 [ 71.972264][ T22] loop_add+0x51/0x8d0 [ 71.972276][ T22] loop_control_ioctl+0x22d/0x360 [ 71.972292][ T22] do_vfs_ioctl+0xdb6/0x13e0 [ 71.972302][ T22] ksys_ioctl+0xab/0xd0 [ 71.972320][ T22] __x64_sys_ioctl+0x73/0xb0 [ 71.972350][ T22] do_syscall_64+0xfd/0x680 [ 71.979728][ T8905] kobject: 'mq' (00000000c0a017f3): kobject_add_internal: parent: 'loop0', set: '' [ 71.981993][ T22] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.981998][ T22] [ 71.982004][ T22] Freed by task 8903: [ 71.982019][ T22] save_stack+0x23/0x90 [ 71.982031][ T22] __kasan_slab_free+0x102/0x150 [ 71.982042][ T22] kasan_slab_free+0xe/0x10 [ 71.982052][ T22] kfree+0x106/0x2a0 [ 71.982062][ T22] loop_remove+0xa1/0xd0 [ 71.982074][ T22] loop_control_ioctl+0x320/0x360 [ 71.982085][ T22] do_vfs_ioctl+0xdb6/0x13e0 [ 71.982102][ T22] ksys_ioctl+0xab/0xd0 [ 71.988363][ T8905] kobject: 'mq' (00000000c0a017f3): kobject_uevent_env [ 71.992422][ T22] __x64_sys_ioctl+0x73/0xb0 [ 71.992438][ T22] do_syscall_64+0xfd/0x680 [ 71.992454][ T22] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.992458][ T22] [ 71.992469][ T22] The buggy address belongs to the object at ffff8880a3ab56c0 [ 71.992469][ T22] which belongs to the cache kmalloc-1k of size 1024 [ 71.992480][ T22] The buggy address is located 528 bytes inside of [ 71.992480][ T22] 1024-byte region [ffff8880a3ab56c0, ffff8880a3ab5ac0) [ 71.992484][ T22] The buggy address belongs to the page: [ 71.992512][ T22] page:ffffea00028ead00 refcount:1 mapcount:0 mapping:ffff8880aa400ac0 index:0x0 compound_mapcount: 0 [ 71.997886][ T8905] kobject: 'mq' (00000000c0a017f3): kobject_uevent_env: filter function caused the event to drop! [ 72.001708][ T22] flags: 0x1fffc0000010200(slab|head) [ 72.001728][ T22] raw: 01fffc0000010200 ffffea000287ae88 ffffea0002589288 ffff8880aa400ac0 [ 72.001742][ T22] raw: 0000000000000000 ffff8880a3ab4040 0000000100000007 0000000000000000 [ 72.001747][ T22] page dumped because: kasan: bad access detected [ 72.001750][ T22] [ 72.001755][ T22] Memory state around the buggy address: [ 72.001765][ T22] ffff8880a3ab5780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.001775][ T22] ffff8880a3ab5800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.001785][ T22] >ffff8880a3ab5880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.001790][ T22] ^ [ 72.001800][ T22] ffff8880a3ab5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.001809][ T22] ffff8880a3ab5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.001813][ T22] ================================================================== [ 72.001818][ T22] Disabling lock debugging due to kernel taint [ 72.010522][ T22] Kernel panic - not syncing: panic_on_warn set ... [ 72.013592][ T8905] kobject: '0' (0000000093e00edd): kobject_add_internal: parent: 'mq', set: '' [ 72.018212][ T22] CPU: 1 PID: 22 Comm: kworker/1:1 Tainted: G B 5.2.0-rc3-next-20190607 #11 [ 72.018220][ T22] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 72.018252][ T22] Workqueue: events __blk_release_queue [ 72.025290][ T8905] kobject: 'cpu0' (0000000085b2b190): kobject_add_internal: parent: '0', set: '' [ 72.028926][ T22] Call Trace: [ 72.028952][ T22] dump_stack+0x172/0x1f0 [ 72.028977][ T22] panic+0x2cb/0x744 [ 72.031768][ T8905] kobject: 'cpu1' (00000000f25a8584): kobject_add_internal: parent: '0', set: '' [ 72.041456][ T22] ? __warn_printk+0xf3/0xf3 [ 72.041474][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 72.041488][ T22] ? preempt_schedule+0x4b/0x60 [ 72.041503][ T22] ? ___preempt_schedule+0x16/0x18 [ 72.041538][ T22] ? trace_hardirqs_on+0x5e/0x220 [ 72.041551][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 72.041566][ T22] end_report+0x47/0x4f [ 72.041588][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 72.046488][ T8905] kobject: 'queue' (00000000b06b5a19): kobject_uevent_env [ 72.050080][ T22] __kasan_report.cold+0xe/0x36 [ 72.050103][ T22] ? blk_mq_free_rqs+0x49f/0x4b0 [ 72.056207][ T8905] kobject: 'queue' (00000000b06b5a19): kobject_uevent_env: filter function caused the event to drop! [ 72.065822][ T22] kasan_report+0x12/0x20 [ 72.065839][ T22] __asan_report_load8_noabort+0x14/0x20 [ 72.065854][ T22] blk_mq_free_rqs+0x49f/0x4b0 [ 72.065867][ T22] ? dd_exit_queue+0x92/0xd0 [ 72.065876][ T22] ? kfree+0x1ec/0x2a0 [ 72.065893][ T22] blk_mq_sched_tags_teardown+0x126/0x210 [ 72.065913][ T22] ? dd_request_merge+0x230/0x230 [ 72.071113][ T8905] kobject: 'iosched' (00000000f5a87d2d): kobject_add_internal: parent: 'queue', set: '' [ 72.075699][ T22] blk_mq_exit_sched+0x1fa/0x2d0 [ 72.075722][ T22] elevator_exit+0x70/0xa0 [ 72.079904][ T8905] kobject: 'iosched' (00000000f5a87d2d): kobject_uevent_env [ 72.084815][ T22] __blk_release_queue+0x127/0x330 [ 72.084831][ T22] process_one_work+0x989/0x1790 [ 72.084848][ T22] ? pwq_dec_nr_in_flight+0x320/0x320 [ 72.084860][ T22] ? lock_acquire+0x16f/0x3f0 [ 72.084881][ T22] worker_thread+0x98/0xe40 [ 72.090928][ T8905] kobject: 'iosched' (00000000f5a87d2d): kobject_uevent_env: filter function caused the event to drop! [ 72.093643][ T22] kthread+0x354/0x420 [ 72.093665][ T22] ? process_one_work+0x1790/0x1790 [ 72.098371][ T8905] kobject: 'integrity' (00000000639f85af): kobject_add_internal: parent: 'loop0', set: '' [ 72.102755][ T22] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 72.102773][ T22] ret_from_fork+0x24/0x30 [ 72.103989][ T22] Kernel Offset: disabled [ 72.645036][ T22] Rebooting in 86400 seconds..