[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 35.784460] random: sshd: uninitialized urandom read (32 bytes read) [ 35.980838] kauditd_printk_skb: 11 callbacks suppressed [ 35.980846] audit: type=1400 audit(1556487037.801:35): avc: denied { map } for pid=6974 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 [ 36.037364] random: sshd: uninitialized urandom read (32 bytes read) [ 36.655981] random: sshd: uninitialized urandom read (32 bytes read) [ 124.595982] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.231' (ECDSA) to the list of known hosts. [ 130.307412] random: sshd: uninitialized urandom read (32 bytes read) [ 130.435808] audit: type=1400 audit(1556487132.251:36): avc: denied { map } for pid=6986 comm="syz-executor537" path="/root/syz-executor537480935" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 131.170373] IPVS: ftp: loaded support on port[0] = 21 executing program [ 132.320218] IPVS: ftp: loaded support on port[0] = 21 executing program [ 133.360263] IPVS: ftp: loaded support on port[0] = 21 executing program [ 134.410319] IPVS: ftp: loaded support on port[0] = 21 executing program [ 135.470313] IPVS: ftp: loaded support on port[0] = 21 executing program [ 136.490252] IPVS: ftp: loaded support on port[0] = 21 executing program [ 138.520548] ================================================================== [ 138.528132] BUG: KASAN: use-after-free in xfrm6_tunnel_destroy+0x52e/0x5d0 [ 138.535286] Read of size 8 at addr ffff8880803956f8 by task kworker/0:2/3144 [ 138.542499] [ 138.544124] CPU: 0 PID: 3144 Comm: kworker/0:2 Not tainted 4.14.114 #4 [ 138.550783] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 138.560219] Workqueue: events xfrm_state_gc_task [ 138.564977] Call Trace: [ 138.567567] dump_stack+0x138/0x19c [ 138.571191] ? xfrm6_tunnel_destroy+0x52e/0x5d0 [ 138.575852] print_address_description.cold+0x7c/0x1dc [ 138.581256] ? xfrm6_tunnel_destroy+0x52e/0x5d0 [ 138.585923] kasan_report.cold+0xaf/0x2b5 [ 138.590075] __asan_report_load8_noabort+0x14/0x20 [ 138.595066] xfrm6_tunnel_destroy+0x52e/0x5d0 [ 138.599563] xfrm_state_gc_task+0x3ef/0x660 [ 138.603877] ? xfrm_state_unregister_afinfo+0x1a0/0x1a0 [ 138.609341] ? rcu_lockdep_current_cpu_online+0xf2/0x140 [ 138.614792] process_one_work+0x868/0x1610 [ 138.619086] ? pwq_dec_nr_in_flight+0x2e0/0x2e0 [ 138.623776] worker_thread+0x5d9/0x1050 [ 138.627748] kthread+0x31c/0x430 [ 138.631116] ? process_one_work+0x1610/0x1610 [ 138.635605] ? kthread_create_on_node+0xd0/0xd0 [ 138.640267] ret_from_fork+0x3a/0x50 [ 138.643965] [ 138.645582] Allocated by task 6993: [ 138.649199] save_stack_trace+0x16/0x20 [ 138.653152] save_stack+0x45/0xd0 [ 138.656591] kasan_kmalloc+0xce/0xf0 [ 138.660299] __kmalloc+0x15d/0x7a0 [ 138.663871] ops_init+0xee/0x3d0 [ 138.667315] setup_net+0x237/0x530 [ 138.670884] copy_net_ns+0x19f/0x440 [ 138.674602] create_new_namespaces+0x37b/0x720 [ 138.679182] unshare_nsproxy_namespaces+0xab/0x1e0 [ 138.684117] SyS_unshare+0x2f3/0x7e0 [ 138.687931] do_syscall_64+0x1eb/0x630 [ 138.691808] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 138.697020] [ 138.698633] Freed by task 2283: [ 138.701900] save_stack_trace+0x16/0x20 [ 138.705902] save_stack+0x45/0xd0 [ 138.709393] kasan_slab_free+0x75/0xc0 [ 138.713276] kfree+0xcc/0x270 [ 138.716366] ops_free_list.part.0+0x1f6/0x320 [ 138.720845] cleanup_net+0x458/0x880 [ 138.724549] process_one_work+0x868/0x1610 [ 138.728784] worker_thread+0x5d9/0x1050 [ 138.732862] kthread+0x31c/0x430 [ 138.736238] ret_from_fork+0x3a/0x50 [ 138.739938] [ 138.741548] The buggy address belongs to the object at ffff888080395640 [ 138.741548] which belongs to the cache kmalloc-8192 of size 8192 [ 138.754388] The buggy address is located 184 bytes inside of [ 138.754388] 8192-byte region [ffff888080395640, ffff888080397640) [ 138.766590] The buggy address belongs to the page: [ 138.771596] page:ffffea000200e500 count:1 mapcount:0 mapping:ffff888080395640 index:0x0 compound_mapcount: 0 [ 138.781678] flags: 0x1fffc0000008100(slab|head) [ 138.786560] raw: 01fffc0000008100 ffff888080395640 0000000000000000 0000000100000001 [ 138.794517] raw: ffffea000282c820 ffffea0002839e20 ffff8880aa802080 0000000000000000 [ 138.802708] page dumped because: kasan: bad access detected [ 138.812817] [ 138.814427] Memory state around the buggy address: [ 138.819353] ffff888080395580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 138.826775] ffff888080395600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 138.834211] >ffff888080395680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 138.841587] ^ [ 138.848867] ffff888080395700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 138.856218] ffff888080395780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 138.863567] ================================================================== [ 138.870923] Disabling lock debugging due to kernel taint [ 138.876628] Kernel panic - not syncing: panic_on_warn set ... [ 138.876628] [ 138.884109] CPU: 0 PID: 3144 Comm: kworker/0:2 Tainted: G B 4.14.114 #4 [ 138.891994] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 138.901363] Workqueue: events xfrm_state_gc_task [ 138.906310] Call Trace: [ 138.908889] dump_stack+0x138/0x19c [ 138.912866] ? xfrm6_tunnel_destroy+0x52e/0x5d0 [ 138.917536] panic+0x1f2/0x438 [ 138.920719] ? add_taint.cold+0x16/0x16 [ 138.924803] kasan_end_report+0x47/0x4f [ 138.928790] kasan_report.cold+0x136/0x2b5 [ 138.933242] __asan_report_load8_noabort+0x14/0x20 [ 138.938248] xfrm6_tunnel_destroy+0x52e/0x5d0 [ 138.942742] xfrm_state_gc_task+0x3ef/0x660 [ 138.947051] ? xfrm_state_unregister_afinfo+0x1a0/0x1a0 [ 138.952405] ? rcu_lockdep_current_cpu_online+0xf2/0x140 [ 138.957894] process_one_work+0x868/0x1610 [ 138.962211] ? pwq_dec_nr_in_flight+0x2e0/0x2e0 [ 138.966957] worker_thread+0x5d9/0x1050 [ 138.970977] kthread+0x31c/0x430 [ 138.974332] ? process_one_work+0x1610/0x1610 [ 138.978958] ? kthread_create_on_node+0xd0/0xd0 [ 138.983682] ret_from_fork+0x3a/0x50 [ 138.988503] Kernel Offset: disabled [ 138.992126] Rebooting in 86400 seconds..