[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 14.423719] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.748616] random: sshd: uninitialized urandom read (32 bytes read) [ 16.935893] random: sshd: uninitialized urandom read (32 bytes read) [ 17.376388] random: sshd: uninitialized urandom read (32 bytes read) [ 37.813490] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.56' (ECDSA) to the list of known hosts. [ 43.592011] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.480297] ================================================================== [ 46.487728] BUG: KASAN: use-after-free in xfrm6_tunnel_destroy+0x5a4/0x650 [ 46.494727] Read of size 8 at addr ffff8801d29ba8f8 by task kworker/0:1/22 [ 46.501722] [ 46.503339] CPU: 0 PID: 22 Comm: kworker/0:1 Not tainted 4.14.67+ #1 [ 46.509873] Workqueue: events xfrm_state_gc_task [ 46.514610] Call Trace: [ 46.517239] dump_stack+0xb9/0x11b [ 46.520788] print_address_description+0x60/0x22b [ 46.525616] kasan_report.cold.6+0x11b/0x2dd [ 46.529999] ? xfrm6_tunnel_destroy+0x5a4/0x650 [ 46.534646] xfrm6_tunnel_destroy+0x5a4/0x650 [ 46.539185] xfrm_state_gc_task+0x3d6/0x550 [ 46.543496] ? xfrm_state_unregister_afinfo+0x180/0x180 [ 46.548846] ? lock_acquire+0x10f/0x380 [ 46.552809] process_one_work+0x86e/0x15c0 [ 46.557036] ? pwq_dec_nr_in_flight+0x2b0/0x2b0 [ 46.561691] worker_thread+0xdc/0x1000 [ 46.565561] ? process_one_work+0x15c0/0x15c0 [ 46.570040] ? process_one_work+0x15c0/0x15c0 [ 46.574626] kthread+0x348/0x420 [ 46.577978] ? kthread_create_on_node+0xe0/0xe0 [ 46.582634] ret_from_fork+0x3a/0x50 [ 46.586335] [ 46.587942] Allocated by task 1992: [ 46.591554] kasan_kmalloc.part.1+0x4f/0xd0 [ 46.595860] __kmalloc+0x153/0x340 [ 46.599377] ops_init+0xec/0x3e0 [ 46.602722] setup_net+0x22b/0x510 [ 46.606244] copy_net_ns+0x193/0x430 [ 46.610036] create_new_namespaces+0x4f0/0x750 [ 46.614601] unshare_nsproxy_namespaces+0x9f/0x1d0 [ 46.619510] SyS_unshare+0x314/0x6b0 [ 46.623281] do_syscall_64+0x19b/0x4b0 [ 46.627166] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.632336] [ 46.633943] Freed by task 65: [ 46.637029] kasan_slab_free+0xac/0x190 [ 46.640979] kfree+0xf5/0x310 [ 46.644058] ops_free_list.part.4+0x22a/0x350 [ 46.648534] cleanup_net+0x481/0x880 [ 46.652414] process_one_work+0x86e/0x15c0 [ 46.656624] worker_thread+0xdc/0x1000 [ 46.660486] kthread+0x348/0x420 [ 46.663939] ret_from_fork+0x3a/0x50 [ 46.667688] [ 46.669298] The buggy address belongs to the object at ffff8801d29ba100 [ 46.669298] which belongs to the cache kmalloc-8192 of size 8192 [ 46.682171] The buggy address is located 2040 bytes inside of [ 46.682171] 8192-byte region [ffff8801d29ba100, ffff8801d29bc100) [ 46.694199] The buggy address belongs to the page: [ 46.699179] page:ffffea00074a6e00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 46.709129] flags: 0x4000000000008100(slab|head) [ 46.713866] raw: 4000000000008100 0000000000000000 0000000000000000 0000000100030003 [ 46.721726] raw: dead000000000100 dead000000000200 ffff8801da802400 0000000000000000 [ 46.729638] page dumped because: kasan: bad access detected [ 46.735326] [ 46.736929] Memory state around the buggy address: [ 46.741841] ffff8801d29ba780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.749182] ffff8801d29ba800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.756528] >ffff8801d29ba880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.763920] ^ [ 46.771176] ffff8801d29ba900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.778580] ffff8801d29ba980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.785940] ================================================================== [ 46.793286] Disabling lock debugging due to kernel taint [ 46.798804] Kernel panic - not syncing: panic_on_warn set ... [ 46.798804] [ 46.806206] CPU: 0 PID: 22 Comm: kworker/0:1 Tainted: G B 4.14.67+ #1 [ 46.813900] Workqueue: events xfrm_state_gc_task [ 46.818630] Call Trace: [ 46.821261] dump_stack+0xb9/0x11b [ 46.824793] panic+0x1bf/0x3a4 [ 46.828055] ? add_taint.cold.4+0x16/0x16 [ 46.832183] kasan_end_report+0x43/0x49 [ 46.836131] kasan_report.cold.6+0x77/0x2dd [ 46.840439] ? xfrm6_tunnel_destroy+0x5a4/0x650 [ 46.845095] xfrm6_tunnel_destroy+0x5a4/0x650 [ 46.849579] xfrm_state_gc_task+0x3d6/0x550 [ 46.853887] ? xfrm_state_unregister_afinfo+0x180/0x180 [ 46.859233] ? lock_acquire+0x10f/0x380 [ 46.863191] process_one_work+0x86e/0x15c0 [ 46.867411] ? pwq_dec_nr_in_flight+0x2b0/0x2b0 [ 46.872112] worker_thread+0xdc/0x1000 [ 46.875988] ? process_one_work+0x15c0/0x15c0 [ 46.880462] ? process_one_work+0x15c0/0x15c0 [ 46.884933] kthread+0x348/0x420 [ 46.888273] ? kthread_create_on_node+0xe0/0xe0 [ 46.892968] ret_from_fork+0x3a/0x50 [ 46.896969] Dumping ftrace buffer: [ 46.900529] (ftrace buffer empty) [ 46.904222] Kernel Offset: 0x2ec00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 46.915215] Rebooting in 86400 seconds..