[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 58.805552][ T26] audit: type=1800 audit(1574595119.638:25): pid=8629 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 58.845316][ T26] audit: type=1800 audit(1574595119.638:26): pid=8629 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 58.878657][ T26] audit: type=1800 audit(1574595119.638:27): pid=8629 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.47' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 67.248099][ T8786] nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. executing program executing program executing program executing program executing program executing program executing program [ 68.522633][ T8807] kasan: CONFIG_KASAN_INLINE enabled [ 68.529301][ T8807] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 68.538593][ T8807] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 68.546371][ T8807] CPU: 1 PID: 8807 Comm: syz-executor392 Not tainted 5.4.0-rc8-syzkaller #0 [ 68.555230][ T8807] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.567023][ T8807] RIP: 0010:skb_unlink+0xc4/0x160 [ 68.572147][ T8807] Code: 00 00 49 8d 7d 08 4c 8b 63 08 48 b8 00 00 00 00 00 fc ff df 48 c7 43 08 00 00 00 00 48 89 fa 48 c7 03 00 00 00 00 48 c1 ea 03 <80> 3c 02 00 75 58 4c 89 e2 4d 89 65 08 48 b8 00 00 00 00 00 fc ff [ 68.592183][ T8807] RSP: 0018:ffff8880a0e87908 EFLAGS: 00010002 [ 68.599379][ T8807] RAX: dffffc0000000000 RBX: ffff88809fcc9540 RCX: ffffffff815a6e2a [ 68.607449][ T8807] RDX: 0000000000000001 RSI: 0000000000000282 RDI: 0000000000000008 [ 68.615519][ T8807] RBP: ffff8880a0e87930 R08: 0000000000000004 R09: ffffed10141d0f0e [ 68.623486][ T8807] R10: ffffed10141d0f0d R11: 0000000000000003 R12: 0000000000000000 [ 68.631442][ T8807] R13: 0000000000000000 R14: ffff888099424828 R15: ffff8880a0e879d8 [ 68.639633][ T8807] FS: 00007f803503f700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 68.648828][ T8807] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 68.655408][ T8807] CR2: 00000000209ff000 CR3: 0000000092347000 CR4: 00000000001406e0 [ 68.663456][ T8807] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 68.671522][ T8807] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 68.679681][ T8807] Call Trace: [ 68.682975][ T8807] kcm_recvmsg+0x462/0x560 [ 68.687446][ T8807] ? kcm_splice_read+0x360/0x360 [ 68.692417][ T8807] ? kcm_splice_read+0x360/0x360 [ 68.697607][ T8807] sock_recvmsg_nosec+0x89/0xb0 [ 68.702707][ T8807] ? __sock_tx_timestamp+0xd0/0xd0 [ 68.707827][ T8807] ___sys_recvmsg+0x271/0x5c0 [ 68.712580][ T8807] ? __kasan_check_read+0x11/0x20 [ 68.717790][ T8807] ? ___sys_sendmsg+0x920/0x920 [ 68.722628][ T8807] ? __kasan_check_read+0x11/0x20 [ 68.727636][ T8807] ? __might_fault+0x12b/0x1e0 [ 68.732489][ T8807] ? find_held_lock+0x35/0x130 [ 68.737254][ T8807] ? __might_fault+0x12b/0x1e0 [ 68.744355][ T8807] ? ksys_dup3+0x3e0/0x3e0 [ 68.748864][ T8807] ? lock_downgrade+0x920/0x920 [ 68.753979][ T8807] do_recvmmsg+0x27e/0x7a0 [ 68.758404][ T8807] ? ___sys_recvmsg+0x5c0/0x5c0 [ 68.763252][ T8807] ? __fd_install+0x1bc/0x640 [ 68.767924][ T8807] ? lock_downgrade+0x920/0x920 [ 68.772758][ T8807] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.779030][ T8807] ? __fd_install+0x200/0x640 [ 68.783691][ T8807] __sys_recvmmsg+0x259/0x270 [ 68.788372][ T8807] ? __ia32_sys_recvmsg+0xb0/0xb0 [ 68.795745][ T8807] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 68.801384][ T8807] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 68.806913][ T8807] ? do_syscall_64+0x26/0x760 [ 68.811575][ T8807] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.817726][ T8807] ? do_syscall_64+0x26/0x760 [ 68.822392][ T8807] __x64_sys_recvmmsg+0xe6/0x140 [ 68.827319][ T8807] do_syscall_64+0xfa/0x760 [ 68.831813][ T8807] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.837692][ T8807] RIP: 0033:0x446a39 [ 68.841570][ T8807] Code: e8 5c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 68.863330][ T8807] RSP: 002b:00007f803503ed98 EFLAGS: 00000246 ORIG_RAX: 000000000000012b [ 68.871891][ T8807] RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 0000000000446a39 [ 68.880134][ T8807] RDX: 0400000000000310 RSI: 0000000020003540 RDI: 0000000000000005 [ 68.888102][ T8807] RBP: 00000000006dbc40 R08: 0000000000000000 R09: 0000000000000000 [ 68.896169][ T8807] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc4c [ 68.904135][ T8807] R13: 00000000002b0095 R14: 0000a50000000000 R15: 0000000300000018 [ 68.912102][ T8807] Modules linked in: [ 68.916044][ T8807] ---[ end trace eb72d066863fd158 ]--- [ 68.921605][ T8807] RIP: 0010:skb_unlink+0xc4/0x160 [ 68.926613][ T8807] Code: 00 00 49 8d 7d 08 4c 8b 63 08 48 b8 00 00 00 00 00 fc ff df 48 c7 43 08 00 00 00 00 48 89 fa 48 c7 03 00 00 00 00 48 c1 ea 03 <80> 3c 02 00 75 58 4c 89 e2 4d 89 65 08 48 b8 00 00 00 00 00 fc ff [ 68.947693][ T8807] RSP: 0018:ffff8880a0e87908 EFLAGS: 00010002 [ 68.953841][ T8807] RAX: dffffc0000000000 RBX: ffff88809fcc9540 RCX: ffffffff815a6e2a [ 68.961888][ T8807] RDX: 0000000000000001 RSI: 0000000000000282 RDI: 0000000000000008 [ 68.970152][ T8807] RBP: ffff8880a0e87930 R08: 0000000000000004 R09: ffffed10141d0f0e [ 68.978116][ T8807] R10: ffffed10141d0f0d R11: 0000000000000003 R12: 0000000000000000 [ 68.986073][ T8807] R13: 0000000000000000 R14: ffff888099424828 R15: ffff8880a0e879d8 [ 68.994033][ T8807] FS: 00007f803503f700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 69.002945][ T8807] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 69.009596][ T8807] CR2: 00000000209ff000 CR3: 0000000092347000 CR4: 00000000001406e0 [ 69.017551][ T8807] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 69.025867][ T8807] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 69.033865][ T8807] Kernel panic - not syncing: Fatal exception [ 69.041483][ T8807] Kernel Offset: disabled [ 69.045809][ T8807] Rebooting in 86400 seconds..