[....] Starting enhanced syslogd: rsyslogd[ 13.181520] audit: type=1400 audit(1549217056.188:4): avc: denied { syslog } for pid=1908 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 '10.128.0.237' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program 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: [ 54.138843] ================================================================== [ 54.146228] BUG: KASAN: use-after-free in disk_unblock_events+0x55/0x60 [ 54.152954] Read of size 8 at addr ffff8801d2059ee8 by task blkid/3233 [ 54.159586] [ 54.161199] CPU: 1 PID: 3233 Comm: blkid Not tainted 4.4.172+ #13 [ 54.167406] 0000000000000000 b4f95ede9c3003c2 ffff8801d1a8f730 ffffffff81aacde1 [ 54.175399] 0000000000000000 ffffea0007481600 ffff8801d2059ee8 0000000000000008 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.183411] 0000000000000000 ffff8801d1a8f768 ffffffff8148fedd 0000000000000000 [ 54.191393] Call Trace: [ 54.193952] [] dump_stack+0xc1/0x120 [ 54.199301] [] print_address_description+0x6f/0x21b [ 54.205941] [] kasan_report.cold+0x8c/0x2be [ 54.211902] [] ? disk_unblock_events+0x55/0x60 [ 54.218110] [] __asan_report_load8_noabort+0x14/0x20 [ 54.224841] [] disk_unblock_events+0x55/0x60 [ 54.230873] [] __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 [ 54.236467] [] ? __blkdev_put+0x840/0x840 [ 54.242236] [] ? trace_hardirqs_on+0x10/0x10 [ 54.248267] [] blkdev_get+0x2e8/0x920 [ 54.253689] [] ? bd_may_claim+0xd0/0xd0 [ 54.259282] [] ? bd_acquire+0x8a/0x370 [ 54.264792] [] ? _raw_spin_unlock+0x2d/0x50 [ 54.270735] [] blkdev_open+0x1aa/0x250 [ 54.276247] [] do_dentry_open+0x38f/0xbd0 [ 54.282014] [] ? __inode_permission2+0x9e/0x250 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.288313] [] ? blkdev_get_by_dev+0x80/0x80 [ 54.294346] [] vfs_open+0x10b/0x210 [ 54.299607] [] ? may_open.isra.0+0xe7/0x210 [ 54.305552] [] path_openat+0x136f/0x4470 [ 54.311233] [] ? kasan_kmalloc.part.0+0xc6/0xf0 [ 54.317522] [] ? may_open.isra.0+0x210/0x210 [ 54.323556] [] ? trace_hardirqs_on+0x10/0x10 [ 54.329596] [] do_filp_open+0x1a1/0x270 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 [ 54.335239] [] ? user_path_mountpoint_at+0x50/0x50 [ 54.341790] [] ? __alloc_fd+0x1ea/0x490 [ 54.347418] [] ? _raw_spin_unlock+0x2d/0x50 [ 54.353530] [] do_sys_open+0x2f8/0x600 [ 54.359056] [] ? filp_open+0x70/0x70 [ 54.364432] [] ? retint_user+0x18/0x3c [ 54.369982] [] ? trace_hardirqs_on_caller+0x385/0x5a0 [ 54.376828] [] SyS_open+0x2d/0x40 [ 54.381942] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 54.388506] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.390128] Allocated by task 3213: [ 54.393740] [] save_stack_trace+0x26/0x50 [ 54.399676] [] kasan_kmalloc.part.0+0x62/0xf0 [ 54.405958] [] kasan_kmalloc+0xb7/0xd0 [ 54.411639] [] kmem_cache_alloc_trace+0x123/0x2d0 [ 54.418256] [] alloc_disk_node+0x50/0x3c0 [ 54.424175] [] alloc_disk+0x1b/0x20 [ 54.429572] [] loop_add+0x380/0x830 [ 54.434959] [] loop_probe+0x154/0x180 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 [ 54.440517] [] kobj_lookup+0x221/0x410 [ 54.446225] [] get_gendisk+0x3c/0x2e0 [ 54.451788] [] __blkdev_get+0x39c/0xdf0 [ 54.457583] [] blkdev_get+0x481/0x920 [ 54.463197] [] blkdev_open+0x1aa/0x250 [ 54.468900] [] do_dentry_open+0x38f/0xbd0 [ 54.474834] [] vfs_open+0x10b/0x210 [ 54.480230] [] path_openat+0x136f/0x4470 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.486084] [] do_filp_open+0x1a1/0x270 [ 54.491848] [] do_sys_open+0x2f8/0x600 [ 54.497505] [] compat_SyS_open+0x2a/0x40 [ 54.503330] [] do_fast_syscall_32+0x32d/0xa90 [ 54.509611] [] sysenter_flags_fixed+0xd/0x1a [ 54.515835] [ 54.517456] Freed by task 3233: [ 54.520716] [] save_stack_trace+0x26/0x50 [ 54.526629] [] kasan_slab_free+0xb0/0x190 [ 54.532536] [] kfree+0xf4/0x310 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.537581] [] disk_release+0x255/0x330 [ 54.543328] [] device_release+0x7d/0x220 [ 54.549179] [] kobject_put+0x14c/0x260 [ 54.554843] [] put_disk+0x23/0x30 [ 54.560171] [] __blkdev_get+0x66c/0xdf0 [ 54.565911] [] blkdev_get+0x2e8/0x920 [ 54.571549] [] blkdev_open+0x1aa/0x250 [ 54.577211] [] do_dentry_open+0x38f/0xbd0 [ 54.583119] [] vfs_open+0x10b/0x210 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.588514] [] path_openat+0x136f/0x4470 [ 54.594399] [] do_filp_open+0x1a1/0x270 [ 54.600136] [] do_sys_open+0x2f8/0x600 [ 54.605785] [] SyS_open+0x2d/0x40 [ 54.611057] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 54.617753] [ 54.619417] The buggy address belongs to the object at ffff8801d2059980 [ 54.619417] which belongs to the cache kmalloc-2048 of size 2048 [ 54.632227] The buggy address is located 1384 bytes inside of [ 54.632227] 2048-byte region [ffff8801d2059980, ffff8801d205a180) [ 54.644290] The buggy address belongs to the page: [ 54.649499] BUG: unable to handle kernel paging request at ffffed043a3476e7 [ 54.656909] IP: [] __task_pid_nr_ns+0x361/0x450 [ 54.663 [ 54.664119] BUG: unable to handle kernel NULL pointer dereference at (null) [ 54.664124] IP: [< (null)>] (null) [ 54.664128] ------------[ cut here ]------------ [ 54.664139] WARNING: CPU: 0 PID: -2104943648 at include/linux/uaccess.h:18 __probe_kernel_read+0x1ee/0x230() [ 54.664143] Kernel panic - not syncing: panic_on_warn set ... [ 54.664143] [ 55.852420] Shutting down cpus with NMI [ 55.853381] Kernel Offset: disabled [ 55.896999] Rebooting in 86400 seconds..