[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 39.933277] random: sshd: uninitialized urandom read (32 bytes read) [ 40.347606] kauditd_printk_skb: 10 callbacks suppressed [ 40.347613] audit: type=1400 audit(1569020269.405:35): avc: denied { map } for pid=6884 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 [ 40.404000] random: sshd: uninitialized urandom read (32 bytes read) [ 40.943707] random: sshd: uninitialized urandom read (32 bytes read) [ 41.129991] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.193' (ECDSA) to the list of known hosts. [ 46.701537] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 46.820912] audit: type=1400 audit(1569020275.885:36): avc: denied { map } for pid=6896 comm="syz-executor112" path="/root/syz-executor112873450" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 46.849594] ================================================================== [ 46.857077] BUG: KASAN: use-after-free in tcp_init_tso_segs+0x1ae/0x200 [ 46.863829] Read of size 2 at addr ffff888093ff50b0 by task syz-executor112/6896 [ 46.871371] [ 46.872992] CPU: 1 PID: 6896 Comm: syz-executor112 Not tainted 4.14.145 #0 [ 46.879980] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.889326] Call Trace: [ 46.891897] dump_stack+0x138/0x197 [ 46.895506] ? tcp_init_tso_segs+0x1ae/0x200 [ 46.899905] print_address_description.cold+0x7c/0x1dc [ 46.905163] ? tcp_init_tso_segs+0x1ae/0x200 [ 46.909563] kasan_report.cold+0xa9/0x2af [ 46.913702] __asan_report_load2_noabort+0x14/0x20 [ 46.918622] tcp_init_tso_segs+0x1ae/0x200 [ 46.922834] ? tcp_tso_segs+0x7d/0x1c0 [ 46.926700] tcp_write_xmit+0x15e/0x4960 [ 46.930755] ? tcp_v6_md5_lookup+0x23/0x30 [ 46.934969] ? tcp_established_options+0x2c5/0x420 [ 46.939892] ? tcp_current_mss+0x1dc/0x2f0 [ 46.944109] ? __alloc_skb+0x3ee/0x500 [ 46.947978] __tcp_push_pending_frames+0xa6/0x260 [ 46.953078] tcp_send_fin+0x17e/0xc40 [ 46.956863] tcp_close+0xcc8/0xfb0 [ 46.960387] ? lock_acquire+0x16f/0x430 [ 46.964338] ? ip_mc_drop_socket+0x1d6/0x230 [ 46.968738] inet_release+0xec/0x1c0 [ 46.972434] inet6_release+0x53/0x80 [ 46.976128] __sock_release+0xce/0x2b0 [ 46.980012] ? __sock_release+0x2b0/0x2b0 [ 46.984159] sock_close+0x1b/0x30 [ 46.987593] __fput+0x275/0x7a0 [ 46.990859] ____fput+0x16/0x20 [ 46.994169] task_work_run+0x114/0x190 [ 46.998040] do_exit+0x7df/0x2c10 [ 47.001491] ? mm_update_next_owner+0x5d0/0x5d0 [ 47.006150] ? fd_install+0x4d/0x60 [ 47.009756] ? sock_map_fd+0x56/0x80 [ 47.013454] ? SyS_socket+0x103/0x170 [ 47.017234] do_group_exit+0x111/0x330 [ 47.021104] SyS_exit_group+0x1d/0x20 [ 47.024880] ? do_group_exit+0x330/0x330 [ 47.028920] do_syscall_64+0x1e8/0x640 [ 47.032786] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 47.037701] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 47.042890] RIP: 0033:0x43ee88 [ 47.046059] RSP: 002b:00007ffebf31bec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 47.053769] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee88 [ 47.061023] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 47.068279] RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 47.075536] R10: 0000000020000004 R11: 0000000000000246 R12: 0000000000000001 [ 47.082799] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 47.090063] [ 47.091670] Allocated by task 6896: [ 47.095293] save_stack_trace+0x16/0x20 [ 47.099253] save_stack+0x45/0xd0 [ 47.102686] kasan_kmalloc+0xce/0xf0 [ 47.106377] kasan_slab_alloc+0xf/0x20 [ 47.110258] kmem_cache_alloc_node+0x144/0x780 [ 47.114827] __alloc_skb+0x9c/0x500 [ 47.118433] sk_stream_alloc_skb+0xb3/0x780 [ 47.122735] tcp_sendmsg_locked+0xf61/0x3200 [ 47.127120] tcp_sendmsg+0x30/0x50 [ 47.130653] inet_sendmsg+0x122/0x500 [ 47.134434] sock_sendmsg+0xce/0x110 [ 47.138126] SYSC_sendto+0x206/0x310 [ 47.141819] SyS_sendto+0x40/0x50 [ 47.145267] do_syscall_64+0x1e8/0x640 [ 47.149132] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 47.154295] [ 47.155899] Freed by task 6896: [ 47.159178] save_stack_trace+0x16/0x20 [ 47.163144] save_stack+0x45/0xd0 [ 47.166691] kasan_slab_free+0x75/0xc0 [ 47.170567] kmem_cache_free+0x83/0x2b0 [ 47.174538] kfree_skbmem+0x8d/0x120 [ 47.178231] __kfree_skb+0x1e/0x30 [ 47.181766] tcp_remove_empty_skb.part.0+0x231/0x2e0 [ 47.186850] tcp_sendmsg_locked+0x1ced/0x3200 [ 47.191324] tcp_sendmsg+0x30/0x50 [ 47.195903] inet_sendmsg+0x122/0x500 [ 47.199692] sock_sendmsg+0xce/0x110 [ 47.203483] SYSC_sendto+0x206/0x310 [ 47.207201] SyS_sendto+0x40/0x50 [ 47.210649] do_syscall_64+0x1e8/0x640 [ 47.216080] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 47.221246] [ 47.222854] The buggy address belongs to the object at ffff888093ff5080 [ 47.222854] which belongs to the cache skbuff_fclone_cache of size 472 [ 47.236882] The buggy address is located 48 bytes inside of [ 47.236882] 472-byte region [ffff888093ff5080, ffff888093ff5258) [ 47.249882] The buggy address belongs to the page: [ 47.254794] page:ffffea00024ffd40 count:1 mapcount:0 mapping:ffff888093ff5080 index:0x0 [ 47.262925] flags: 0x1fffc0000000100(slab) [ 47.267167] raw: 01fffc0000000100 ffff888093ff5080 0000000000000000 0000000100000006 [ 47.275037] raw: ffffea00028280e0 ffffea00024c4260 ffff8880a9e19a80 0000000000000000 [ 47.283004] page dumped because: kasan: bad access detected [ 47.288721] [ 47.290329] Memory state around the buggy address: [ 47.295498] ffff888093ff4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 47.302842] ffff888093ff5000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 47.310300] >ffff888093ff5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.317914] ^ [ 47.322838] ffff888093ff5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.346588] ffff888093ff5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.368310] ================================================================== [ 47.375764] Disabling lock debugging due to kernel taint [ 47.382634] Kernel panic - not syncing: panic_on_warn set ... [ 47.382634] [ 47.390026] CPU: 1 PID: 6896 Comm: syz-executor112 Tainted: G B 4.14.145 #0 [ 47.398498] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.407832] Call Trace: [ 47.410409] dump_stack+0x138/0x197 [ 47.414019] ? tcp_init_tso_segs+0x1ae/0x200 [ 47.418522] panic+0x1f2/0x426 [ 47.421697] ? add_taint.cold+0x16/0x16 [ 47.425650] ? ___preempt_schedule+0x16/0x18 [ 47.430044] kasan_end_report+0x47/0x4f [ 47.434025] kasan_report.cold+0x130/0x2af [ 47.438241] __asan_report_load2_noabort+0x14/0x20 [ 47.443153] tcp_init_tso_segs+0x1ae/0x200 [ 47.447364] ? tcp_tso_segs+0x7d/0x1c0 [ 47.451230] tcp_write_xmit+0x15e/0x4960 [ 47.455270] ? tcp_v6_md5_lookup+0x23/0x30 [ 47.459483] ? tcp_established_options+0x2c5/0x420 [ 47.464415] ? tcp_current_mss+0x1dc/0x2f0 [ 47.468644] ? __alloc_skb+0x3ee/0x500 [ 47.472511] __tcp_push_pending_frames+0xa6/0x260 [ 47.477351] tcp_send_fin+0x17e/0xc40 [ 47.481135] tcp_close+0xcc8/0xfb0 [ 47.484655] ? lock_acquire+0x16f/0x430 [ 47.488608] ? ip_mc_drop_socket+0x1d6/0x230 [ 47.493007] inet_release+0xec/0x1c0 [ 47.496701] inet6_release+0x53/0x80 [ 47.500416] __sock_release+0xce/0x2b0 [ 47.504282] ? __sock_release+0x2b0/0x2b0 [ 47.508408] sock_close+0x1b/0x30 [ 47.511844] __fput+0x275/0x7a0 [ 47.515121] ____fput+0x16/0x20 [ 47.518385] task_work_run+0x114/0x190 [ 47.522261] do_exit+0x7df/0x2c10 [ 47.525696] ? mm_update_next_owner+0x5d0/0x5d0 [ 47.530343] ? fd_install+0x4d/0x60 [ 47.533948] ? sock_map_fd+0x56/0x80 [ 47.537640] ? SyS_socket+0x103/0x170 [ 47.541429] do_group_exit+0x111/0x330 [ 47.545296] SyS_exit_group+0x1d/0x20 [ 47.549087] ? do_group_exit+0x330/0x330 [ 47.553164] do_syscall_64+0x1e8/0x640 [ 47.557041] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 47.562166] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 47.567335] RIP: 0033:0x43ee88 [ 47.570504] RSP: 002b:00007ffebf31bec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 47.578257] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee88 [ 47.585622] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 47.592910] RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 47.600161] R10: 0000000020000004 R11: 0000000000000246 R12: 0000000000000001 [ 47.607511] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 47.616200] Kernel Offset: disabled [ 47.619827] Rebooting in 86400 seconds..