[....] Starting enhanced syslogd: rsyslogd[ 13.959867] audit: type=1400 audit(1515925324.142:4): avc: denied { syslog } for pid=3175 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 '10.128.15.213' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 23.553892] IPVS: Creating netns size=2536 id=1 [ 23.567909] IPVS: Creating netns size=2536 id=2 [ 23.591158] IPVS: Creating netns size=2536 id=3 executing program [ 23.620701] IPVS: Creating netns size=2536 id=4 executing program [ 23.646109] IPVS: Creating netns size=2536 id=5 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.682244] IPVS: Creating netns size=2536 id=6 [ 23.698098] IPVS: Creating netns size=2536 id=7 [ 23.721391] IPVS: Creating netns size=2536 id=8 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.754228] ================================================================== [ 34.761655] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 34.768411] Read of size 8 at addr ffff8801c4138560 by task syzkaller554488/8046 [ 34.768418] [ 34.768425] CPU: 1 PID: 8046 Comm: syzkaller554488 Not tainted 4.9.76-gf0f6293 #22 [ 34.768428] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.768439] ffff8801c47df730 ffffffff81d93149 ffffea0007104e00 ffff8801c4138560 [ 34.768446] 0000000000000000 ffff8801c4138560 0000000000000000 ffff8801c47df768 [ 34.768452] ffffffff8153cb43 ffff8801c4138560 0000000000000008 0000000000000000 [ 34.768453] Call Trace: [ 34.768467] [] dump_stack+0xc1/0x128 [ 34.768479] [] print_address_description+0x73/0x280 [ 34.768485] [] kasan_report+0x275/0x360 [ 34.768496] [] ? disk_unblock_events+0x51/0x60 [ 34.768503] [] __asan_report_load8_noabort+0x14/0x20 [ 34.768509] [] disk_unblock_events+0x51/0x60 [ 34.768519] [] __blkdev_get+0x4b5/0xd50 [ 34.768526] [] ? __blkdev_put+0x7e0/0x7e0 [ 34.768533] [] blkdev_get+0x33b/0x960 [ 34.768540] [] ? bd_link_disk_holder+0x6c0/0x6c0 [ 34.768546] [] ? bd_acquire+0x27/0x250 [ 34.768553] [] ? bd_acquire+0x88/0x250 [ 34.768564] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.768571] [] blkdev_open+0x1a5/0x250 [ 34.768578] [] do_dentry_open+0x607/0xc60 [ 34.768584] [] ? blkdev_get_by_dev+0x60/0x60 [ 34.768590] [] vfs_open+0x105/0x220 [ 34.768597] [] ? may_open+0x231/0x2e0 [ 34.768602] [] path_openat+0x5ac/0x2910 [ 34.768608] [] ? path_lookupat+0x3f0/0x3f0 [ 34.768617] [] ? __lock_is_held+0xa1/0xf0 [ 34.768624] [] do_filp_open+0x197/0x290 [ 34.768629] [] ? may_open_dev+0xe0/0xe0 [ 34.768636] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.768643] [] ? __alloc_fd+0x1d7/0x510 [ 34.768649] [] do_sys_open+0x352/0x4c0 [ 34.768655] [] ? filp_open+0x70/0x70 [ 34.768662] [] compat_SyS_open+0x2a/0x40 [ 34.768669] [] ? compat_SyS_getdents64+0x280/0x280 [ 34.768676] [] do_fast_syscall_32+0x2f7/0x890 [ 34.768682] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.768689] [] entry_SYSENTER_compat+0x74/0x83 [ 34.768692] [ 34.768695] Allocated by task 8028: [ 34.768703] save_stack_trace+0x16/0x20 [ 34.768708] save_stack+0x43/0xd0 [ 34.768712] kasan_kmalloc+0xad/0xe0 [ 34.768717] kmem_cache_alloc_trace+0xfb/0x2a0 [ 34.768722] alloc_disk_node+0x54/0x3b0 [ 34.768727] alloc_disk+0x18/0x20 [ 34.768734] loop_add+0x324/0x770 [ 34.768739] loop_probe+0x155/0x180 [ 34.768746] kobj_lookup+0x2ac/0x410 [ 34.768751] get_gendisk+0x37/0x2d0 [ 34.768756] __blkdev_get+0x34f/0xd50 [ 34.768761] blkdev_get+0x33b/0x960 [ 34.768766] blkdev_open+0x1a5/0x250 [ 34.768771] do_dentry_open+0x607/0xc60 [ 34.768776] vfs_open+0x105/0x220 [ 34.768780] path_openat+0x5ac/0x2910 [ 34.768784] do_filp_open+0x197/0x290 [ 34.768789] do_sys_open+0x352/0x4c0 [ 34.768793] compat_SyS_open+0x2a/0x40 [ 34.768798] do_fast_syscall_32+0x2f7/0x890 [ 34.768803] entry_SYSENTER_compat+0x74/0x83 [ 34.768804] [ 34.768807] Freed by task 8046: [ 34.768811] save_stack_trace+0x16/0x20 [ 34.768816] save_stack+0x43/0xd0 [ 34.768820] kasan_slab_free+0x72/0xc0 [ 34.768824] kfree+0x103/0x300 [ 34.768830] disk_release+0x259/0x330 [ 34.768837] device_release+0x7c/0x210 [ 34.768842] kobject_release+0xed/0x1a0 [ 34.768847] kobject_put+0x63/0xc0 [ 34.768852] put_disk+0x23/0x30 [ 34.768857] __blkdev_get+0x415/0xd50 [ 34.768861] blkdev_get+0x33b/0x960 [ 34.768867] blkdev_open+0x1a5/0x250 [ 34.768871] do_dentry_open+0x607/0xc60 [ 34.768876] vfs_open+0x105/0x220 [ 34.768880] path_openat+0x5ac/0x2910 [ 34.768884] do_filp_open+0x197/0x290 [ 34.768889] do_sys_open+0x352/0x4c0 [ 34.768894] compat_SyS_open+0x2a/0x40 [ 34.768898] do_fast_syscall_32+0x2f7/0x890 [ 34.768903] entry_SYSENTER_compat+0x74/0x83 [ 34.768904] [ 34.768909] The buggy address belongs to the object at ffff8801c4138000 [ 34.768909] which belongs to the cache kmalloc-2048 of size 2048 [ 34.768914] The buggy address is located 1376 bytes inside of [ 34.768914] 2048-byte region [ffff8801c4138000, ffff8801c4138800) [ 34.768915] The buggy address belongs to the page: [ 34.768924] page:ffffea0007104e00 count:1 mapcount:0 mapping: (null) index:0xffff8801c413bb80 compound_mapcount: 0 [ 34.768929] flags: 0x8000000000004080(slab|head) [ 34.768931] page dumped because: kasan: bad access detected [ 34.768932] [ 34.768934] Memory state around the buggy address: [ 34.768940] ffff8801c4138400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.768944] ffff8801c4138480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.768948] >ffff8801c4138500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.768951] ^ [ 34.768955] ffff8801c4138580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.768959] ffff8801c4138600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.768961] ================================================================== [ 34.768963] Disabling lock debugging due to kernel taint [ 34.771520] Kernel panic - not syncing: panic_on_warn set ... [ 34.771520] [ 34.771527] CPU: 1 PID: 8046 Comm: syzkaller554488 Tainted: G B 4.9.76-gf0f6293 #22 [ 34.771531] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.771543] ffff8801c47df688 ffffffff81d93149 ffffffff84195c17 ffff8801c47df760 [ 34.771551] 0000000000000000 ffff8801c4138560 0000000000000000 ffff8801c47df750 [ 34.771559] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 34.771561] Call Trace: [ 34.771573] [] dump_stack+0xc1/0x128 [ 34.771583] [] panic+0x1bc/0x3a8 [ 34.771592] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 34.771602] [] ? preempt_schedule+0x25/0x30 [ 34.771610] [] ? ___preempt_schedule+0x16/0x18 [ 34.771619] [] kasan_end_report+0x50/0x50 [ 34.771625] [] kasan_report+0x167/0x360 [ 34.771634] [] ? disk_unblock_events+0x51/0x60 [ 34.771641] [] __asan_report_load8_noabort+0x14/0x20 [ 34.771648] [] disk_unblock_events+0x51/0x60 [ 34.771658] [] __blkdev_get+0x4b5/0xd50 [ 34.771665] [] ? __blkdev_put+0x7e0/0x7e0 [ 34.771671] [] blkdev_get+0x33b/0x960 [ 34.771679] [] ? bd_link_disk_holder+0x6c0/0x6c0 [ 34.771685] [] ? bd_acquire+0x27/0x250 [ 34.771691] [] ? bd_acquire+0x88/0x250 [ 34.771699] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.771706] [] blkdev_open+0x1a5/0x250 [ 34.771713] [] do_dentry_open+0x607/0xc60 [ 34.771720] [] ? blkdev_get_by_dev+0x60/0x60 [ 34.771725] [] vfs_open+0x105/0x220 [ 34.771731] [] ? may_open+0x231/0x2e0 [ 34.771735] [] path_openat+0x5ac/0x2910 [ 34.771740] [] ? path_lookupat+0x3f0/0x3f0 [ 34.771750] [] ? __lock_is_held+0xa1/0xf0 [ 34.771756] [] do_filp_open+0x197/0x290 [ 34.771762] [] ? may_open_dev+0xe0/0xe0 [ 34.771769] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.771777] [] ? __alloc_fd+0x1d7/0x510 [ 34.771784] [] do_sys_open+0x352/0x4c0 [ 34.771790] [] ? filp_open+0x70/0x70 [ 34.771798] [] compat_SyS_open+0x2a/0x40 [ 34.771805] [] ? compat_SyS_getdents64+0x280/0x280 [ 34.771811] [] do_fast_syscall_32+0x2f7/0x890 [ 34.771817] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.771824] [] entry_SYSENTER_compat+0x74/0x83 [ 34.776414] Dumping ftrace buffer: [ 34.776418] (ftrace buffer empty) [ 34.776421] Kernel Offset: disabled [ 35.558146] Rebooting in 86400 seconds..