[ 32.122589] audit: type=1800 audit(1569036373.773:33): pid=6760 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [ 32.150649] audit: type=1800 audit(1569036373.773:34): pid=6760 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 38.462456] random: sshd: uninitialized urandom read (32 bytes read) [ 38.867889] audit: type=1400 audit(1569036380.513:35): avc: denied { map } for pid=6934 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 [ 38.917164] random: sshd: uninitialized urandom read (32 bytes read) [ 39.456841] random: sshd: uninitialized urandom read (32 bytes read) [ 39.636330] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.48' (ECDSA) to the list of known hosts. [ 46.194361] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 46.311208] audit: type=1400 audit(1569036387.963:36): avc: denied { map } for pid=6947 comm="syz-executor924" path="/root/syz-executor924202635" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 46.339641] ================================================================== [ 46.347120] BUG: KASAN: use-after-free in tcp_init_tso_segs+0x1ae/0x200 [ 46.354030] Read of size 2 at addr ffff888096c44530 by task syz-executor924/6947 [ 46.361545] [ 46.363160] CPU: 1 PID: 6947 Comm: syz-executor924 Not tainted 4.14.145 #0 [ 46.370160] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.379500] Call Trace: [ 46.382075] dump_stack+0x138/0x197 [ 46.385688] ? tcp_init_tso_segs+0x1ae/0x200 [ 46.390102] print_address_description.cold+0x7c/0x1dc [ 46.395371] ? tcp_init_tso_segs+0x1ae/0x200 [ 46.399773] kasan_report.cold+0xa9/0x2af [ 46.403904] __asan_report_load2_noabort+0x14/0x20 [ 46.408814] tcp_init_tso_segs+0x1ae/0x200 [ 46.413039] ? tcp_tso_segs+0x7d/0x1c0 [ 46.416927] tcp_write_xmit+0x15e/0x4960 [ 46.420988] ? tcp_v6_md5_lookup+0x23/0x30 [ 46.425212] ? tcp_established_options+0x2c5/0x420 [ 46.430131] ? tcp_current_mss+0x1dc/0x2f0 [ 46.434356] ? __alloc_skb+0x3ee/0x500 [ 46.438226] __tcp_push_pending_frames+0xa6/0x260 [ 46.443060] tcp_send_fin+0x17e/0xc40 [ 46.446852] tcp_close+0xcc8/0xfb0 [ 46.450377] ? lock_acquire+0x16f/0x430 [ 46.454334] ? ip_mc_drop_socket+0x1d6/0x230 [ 46.458744] inet_release+0xec/0x1c0 [ 46.462443] inet6_release+0x53/0x80 [ 46.466139] __sock_release+0xce/0x2b0 [ 46.470014] ? __sock_release+0x2b0/0x2b0 [ 46.474171] sock_close+0x1b/0x30 [ 46.477636] __fput+0x275/0x7a0 [ 46.480905] ____fput+0x16/0x20 [ 46.484166] task_work_run+0x114/0x190 [ 46.488053] do_exit+0x7df/0x2c10 [ 46.491492] ? mm_update_next_owner+0x5d0/0x5d0 [ 46.496144] ? fd_install+0x4d/0x60 [ 46.499753] ? sock_map_fd+0x56/0x80 [ 46.503454] ? SyS_socket+0x103/0x170 [ 46.507247] do_group_exit+0x111/0x330 [ 46.511120] SyS_exit_group+0x1d/0x20 [ 46.514902] ? do_group_exit+0x330/0x330 [ 46.518947] do_syscall_64+0x1e8/0x640 [ 46.522832] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 46.527664] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.532838] RIP: 0033:0x43ee88 [ 46.536029] RSP: 002b:00007ffd78aa5ab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 46.543739] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee88 [ 46.551001] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 46.558307] RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 46.565564] R10: 0000000020000004 R11: 0000000000000246 R12: 0000000000000001 [ 46.573025] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 46.580340] [ 46.581949] Allocated by task 6947: [ 46.585636] save_stack_trace+0x16/0x20 [ 46.589613] save_stack+0x45/0xd0 [ 46.593057] kasan_kmalloc+0xce/0xf0 [ 46.596751] kasan_slab_alloc+0xf/0x20 [ 46.600626] kmem_cache_alloc_node+0x144/0x780 [ 46.605189] __alloc_skb+0x9c/0x500 [ 46.608798] sk_stream_alloc_skb+0xb3/0x780 [ 46.613099] tcp_sendmsg_locked+0xf61/0x3200 [ 46.617486] tcp_sendmsg+0x30/0x50 [ 46.621005] inet_sendmsg+0x122/0x500 [ 46.624797] sock_sendmsg+0xce/0x110 [ 46.628491] SYSC_sendto+0x206/0x310 [ 46.632183] SyS_sendto+0x40/0x50 [ 46.635616] do_syscall_64+0x1e8/0x640 [ 46.639483] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.644650] [ 46.646283] Freed by task 6947: [ 46.649541] save_stack_trace+0x16/0x20 [ 46.653503] save_stack+0x45/0xd0 [ 46.656938] kasan_slab_free+0x75/0xc0 [ 46.660805] kmem_cache_free+0x83/0x2b0 [ 46.664757] kfree_skbmem+0x8d/0x120 [ 46.668449] __kfree_skb+0x1e/0x30 [ 46.671985] tcp_remove_empty_skb.part.0+0x231/0x2e0 [ 46.677087] tcp_sendmsg_locked+0x1ced/0x3200 [ 46.681572] tcp_sendmsg+0x30/0x50 [ 46.685100] inet_sendmsg+0x122/0x500 [ 46.688900] sock_sendmsg+0xce/0x110 [ 46.692602] SYSC_sendto+0x206/0x310 [ 46.696299] SyS_sendto+0x40/0x50 [ 46.699738] do_syscall_64+0x1e8/0x640 [ 46.703615] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.708782] [ 46.710398] The buggy address belongs to the object at ffff888096c44500 [ 46.710398] which belongs to the cache skbuff_fclone_cache of size 472 [ 46.723731] The buggy address is located 48 bytes inside of [ 46.723731] 472-byte region [ffff888096c44500, ffff888096c446d8) [ 46.735525] The buggy address belongs to the page: [ 46.740438] page:ffffea00025b1100 count:1 mapcount:0 mapping:ffff888096c44000 index:0x0 [ 46.748564] flags: 0x1fffc0000000100(slab) [ 46.752793] raw: 01fffc0000000100 ffff888096c44000 0000000000000000 0000000100000006 [ 46.760654] raw: ffffea00020415a0 ffffea00024c1860 ffff8880a9e19a80 0000000000000000 [ 46.768527] page dumped because: kasan: bad access detected [ 46.774227] [ 46.775833] Memory state around the buggy address: [ 46.781187] ffff888096c44400: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc [ 46.788680] ffff888096c44480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 46.796031] >ffff888096c44500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.803373] ^ [ 46.808284] ffff888096c44580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.815683] ffff888096c44600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.823029] ================================================================== [ 46.830369] Disabling lock debugging due to kernel taint [ 46.838047] Kernel panic - not syncing: panic_on_warn set ... [ 46.838047] [ 46.845441] CPU: 0 PID: 6947 Comm: syz-executor924 Tainted: G B 4.14.145 #0 [ 46.853652] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.862988] Call Trace: [ 46.865564] dump_stack+0x138/0x197 [ 46.869189] ? tcp_init_tso_segs+0x1ae/0x200 [ 46.873577] panic+0x1f2/0x426 [ 46.876764] ? add_taint.cold+0x16/0x16 [ 46.880720] ? ___preempt_schedule+0x16/0x18 [ 46.885111] kasan_end_report+0x47/0x4f [ 46.889063] kasan_report.cold+0x130/0x2af [ 46.893276] __asan_report_load2_noabort+0x14/0x20 [ 46.898181] tcp_init_tso_segs+0x1ae/0x200 [ 46.902395] ? tcp_tso_segs+0x7d/0x1c0 [ 46.906262] tcp_write_xmit+0x15e/0x4960 [ 46.910305] ? tcp_v6_md5_lookup+0x23/0x30 [ 46.914520] ? tcp_established_options+0x2c5/0x420 [ 46.919430] ? tcp_current_mss+0x1dc/0x2f0 [ 46.923654] ? __alloc_skb+0x3ee/0x500 [ 46.928825] __tcp_push_pending_frames+0xa6/0x260 [ 46.933652] tcp_send_fin+0x17e/0xc40 [ 46.937448] tcp_close+0xcc8/0xfb0 [ 46.940985] ? lock_acquire+0x16f/0x430 [ 46.944941] ? ip_mc_drop_socket+0x1d6/0x230 [ 46.949330] inet_release+0xec/0x1c0 [ 46.953021] inet6_release+0x53/0x80 [ 46.956726] __sock_release+0xce/0x2b0 [ 46.960593] ? __sock_release+0x2b0/0x2b0 [ 46.964725] sock_close+0x1b/0x30 [ 46.968168] __fput+0x275/0x7a0 [ 46.971428] ____fput+0x16/0x20 [ 46.974700] task_work_run+0x114/0x190 [ 46.978571] do_exit+0x7df/0x2c10 [ 46.982003] ? mm_update_next_owner+0x5d0/0x5d0 [ 46.986659] ? fd_install+0x4d/0x60 [ 46.990263] ? sock_map_fd+0x56/0x80 [ 46.993953] ? SyS_socket+0x103/0x170 [ 46.997732] do_group_exit+0x111/0x330 [ 47.001611] SyS_exit_group+0x1d/0x20 [ 47.005401] ? do_group_exit+0x330/0x330 [ 47.009463] do_syscall_64+0x1e8/0x640 [ 47.013331] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 47.018170] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 47.023949] RIP: 0033:0x43ee88 [ 47.027129] RSP: 002b:00007ffd78aa5ab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 47.034815] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee88 [ 47.042067] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 47.049317] RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 47.056570] R10: 0000000020000004 R11: 0000000000000246 R12: 0000000000000001 [ 47.063821] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 47.072520] Kernel Offset: disabled [ 47.076156] Rebooting in 86400 seconds..