[....] 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 syzkaller login: [ 25.578190] random: sshd: uninitialized urandom read (32 bytes read) [ 26.170945] audit: type=1400 audit(1548685970.070:6): avc: denied { map } for pid=1756 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 26.205516] random: sshd: uninitialized urandom read (32 bytes read) [ 26.672124] random: sshd: uninitialized urandom read (32 bytes read) [ 79.127018] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.193' (ECDSA) to the list of known hosts. [ 84.689777] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 84.776787] audit: type=1400 audit(1548686028.670:7): avc: denied { map } for pid=1804 comm="syz-executor911" path="/root/syz-executor911613603" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 87.077610] ================================================================== [ 87.085184] BUG: KASAN: use-after-free in disk_unblock_events+0x4b/0x50 [ 87.091948] Read of size 8 at addr ffff8881cd5ce2e8 by task blkid/2125 [ 87.098606] [ 87.100242] CPU: 1 PID: 2125 Comm: blkid Not tainted 4.14.96+ #19 [ 87.106469] Call Trace: [ 87.109059] dump_stack+0xb9/0x10e [ 87.112602] ? disk_unblock_events+0x4b/0x50 [ 87.117013] print_address_description+0x60/0x226 [ 87.121854] ? disk_unblock_events+0x4b/0x50 [ 87.126261] kasan_report.cold+0x88/0x2a5 [ 87.130416] ? disk_unblock_events+0x4b/0x50 [ 87.134824] ? __blkdev_get+0x68f/0xf90 [ 87.138806] ? __blkdev_put+0x6d0/0x6d0 [ 87.143134] ? fsnotify+0x824/0x10c0 [ 87.146861] ? blkdev_get+0x97/0x8b0 [ 87.150580] ? bd_acquire+0x171/0x2c0 [ 87.154382] ? bd_may_claim+0xd0/0xd0 [ 87.158179] ? lock_downgrade+0x5d0/0x5d0 [ 87.162326] ? lock_acquire+0x10f/0x380 [ 87.166303] ? bd_acquire+0x21/0x2c0 [ 87.170029] ? blkdev_open+0x1cc/0x250 [ 87.173915] ? security_file_open+0x88/0x190 [ 87.178324] ? do_dentry_open+0x41b/0xd60 [ 87.182477] ? bd_acquire+0x2c0/0x2c0 [ 87.186294] ? vfs_open+0x105/0x230 [ 87.190010] ? path_openat+0xb6b/0x2b70 [ 87.193997] ? path_mountpoint+0x9a0/0x9a0 [ 87.198244] ? trace_hardirqs_on+0x10/0x10 [ 87.202489] ? do_filp_open+0x1a1/0x280 [ 87.206465] ? may_open_dev+0xe0/0xe0 [ 87.210276] ? lock_downgrade+0x5d0/0x5d0 [ 87.214432] ? lock_acquire+0x10f/0x380 [ 87.218408] ? __alloc_fd+0x3f/0x490 [ 87.222131] ? _raw_spin_unlock+0x29/0x40 [ 87.226277] ? __alloc_fd+0x1bf/0x490 [ 87.230093] ? do_sys_open+0x2ca/0x590 [ 87.233983] ? filp_open+0x60/0x60 [ 87.237533] ? do_syscall_64+0x43/0x4b0 [ 87.241508] ? do_sys_open+0x590/0x590 [ 87.245399] ? do_syscall_64+0x19b/0x4b0 [ 87.249466] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 87.254840] [ 87.256466] Allocated by task 2123: [ 87.260101] kasan_kmalloc.part.0+0x4f/0xd0 [ 87.264419] kmem_cache_alloc_trace+0x126/0x310 [ 87.269087] alloc_disk_node+0x5b/0x3d0 [ 87.273048] [ 87.274667] Freed by task 2125: [ 87.277949] kasan_slab_free+0xb0/0x190 [ 87.281924] kfree+0xf5/0x310 [ 87.285024] device_release+0xf4/0x1a0 [ 87.288898] [ 87.290523] The buggy address belongs to the object at ffff8881cd5cdd80 [ 87.290523] which belongs to the cache kmalloc-2048 of size 2048 [ 87.303449] The buggy address is located 1384 bytes inside of [ 87.303449] 2048-byte region [ffff8881cd5cdd80, ffff8881cd5ce580) [ 87.315494] The buggy address belongs to the page: [ 87.320422] page:ffffea0007357200 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 87.330392] flags: 0x4000000000008100(slab|head) [ 87.335146] raw: 4000000000008100 0000000000000000 0000000000000000 00000001800f000f [ 87.343027] raw: dead000000000100 dead000000000200 ffff8881da802800 0000000000000000 [ 87.350897] page dumped because: kasan: bad access detected [ 87.356596] [ 87.358222] Memory state around the buggy address: [ 87.363147] ffff8881cd5ce180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.370504] ffff8881cd5ce200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 87.377858] >ffff8881cd5ce280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.385218] ^ [ 87.391970] ffff8881cd5ce300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.399331] ffff8881cd5ce380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.406681] ================================================================== [ 87.414034] Disabling lock debugging due to kernel taint [ 87.437116] Kernel panic - not syncing: panic_on_warn set ... [ 87.437116] [ 87.444514] CPU: 1 PID: 2125 Comm: blkid Tainted: G B 4.14.96+ #19 [ 87.451953] Call Trace: [ 87.454542] dump_stack+0xb9/0x10e [ 87.458081] panic+0x1d9/0x3c2 [ 87.461278] ? add_taint.cold+0x16/0x16 [ 87.465253] ? disk_unblock_events+0x4b/0x50 [ 87.469658] ? ___preempt_schedule+0x16/0x18 [ 87.474066] ? disk_unblock_events+0x4b/0x50 [ 87.478465] kasan_end_report+0x43/0x49 [ 87.482421] kasan_report.cold+0xa4/0x2a5 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 87.486558] ? disk_unblock_events+0x4b/0x50 [ 87.490965] ? __blkdev_get+0x68f/0xf90 [ 87.494938] ? __blkdev_put+0x6d0/0x6d0 [ 87.498910] ? fsnotify+0x824/0x10c0 [ 87.502626] ? blkdev_get+0x97/0x8b0 [ 87.506335] ? bd_acquire+0x171/0x2c0 [ 87.510135] ? bd_may_claim+0xd0/0xd0 [ 87.513929] ? lock_downgrade+0x5d0/0x5d0 [ 87.518075] ? lock_acquire+0x10f/0x380 [ 87.522439] ? bd_acquire+0x21/0x2c0 [ 87.526143] ? blkdev_open+0x1cc/0x250 [ 87.530029] ? security_file_open+0x88/0x190 [ 87.534437] ? do_dentry_open+0x41b/0xd60 [ 87.538583] ? bd_acquire+0x2c0/0x2c0 [ 87.542383] ? vfs_open+0x105/0x230 [ 87.546011] ? path_openat+0xb6b/0x2b70 [ 87.549983] ? path_mountpoint+0x9a0/0x9a0 [ 87.554220] ? trace_hardirqs_on+0x10/0x10 [ 87.558453] ? do_filp_open+0x1a1/0x280 [ 87.562427] ? may_open_dev+0xe0/0xe0 [ 87.566230] ? lock_downgrade+0x5d0/0x5d0 [ 87.570373] ? lock_acquire+0x10f/0x380 [ 87.574348] ? __alloc_fd+0x3f/0x490 [ 87.578069] ? _raw_spin_unlock+0x29/0x40 [ 87.582216] ? __alloc_fd+0x1bf/0x490 [ 87.586013] ? do_sys_open+0x2ca/0x590 [ 87.589888] ? filp_open+0x60/0x60 [ 87.593423] ? do_syscall_64+0x43/0x4b0 [ 87.597390] ? do_sys_open+0x590/0x590 [ 87.601282] ? do_syscall_64+0x19b/0x4b0 [ 87.605334] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 87.611121] Kernel Offset: 0x9000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 87.621941] Rebooting in 86400 seconds..