[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 35.943175] audit: type=1800 audit(1569077902.052:33): pid=7231 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 [ 35.966874] audit: type=1800 audit(1569077902.052:34): pid=7231 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: [ 40.593931] audit: type=1400 audit(1569077906.702:35): avc: denied { map } for pid=7406 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 Warning: Permanently added '10.128.1.11' (ECDSA) to the list of known hosts. executing program [ 47.041300] audit: type=1400 audit(1569077913.142:36): avc: denied { map } for pid=7418 comm="syz-executor317" path="/root/syz-executor317646007" 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 [ 47.059328] IPVS: ftp: loaded support on port[0] = 21 [ 47.183173] ================================================================== [ 47.190646] BUG: KASAN: use-after-free in __change_pid+0x253/0x2f0 [ 47.196952] Read of size 8 at addr ffff8880a17b8c80 by task syz-executor317/7418 [ 47.204554] [ 47.206171] CPU: 1 PID: 7418 Comm: syz-executor317 Not tainted 4.19.75 #0 [ 47.213092] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.222430] Call Trace: [ 47.225008] dump_stack+0x172/0x1f0 [ 47.228622] ? __change_pid+0x253/0x2f0 [ 47.232584] print_address_description.cold+0x7c/0x20d [ 47.237858] ? __change_pid+0x253/0x2f0 [ 47.241817] kasan_report.cold+0x8c/0x2ba [ 47.245950] __asan_report_load8_noabort+0x14/0x20 [ 47.250864] __change_pid+0x253/0x2f0 [ 47.254651] detach_pid+0x20/0x30 [ 47.258101] release_task+0xd65/0x1630 [ 47.261974] ? _raw_spin_unlock_irq+0x28/0x90 [ 47.266460] wait_consider_task+0x2c95/0x3910 [ 47.270945] ? release_task+0x1630/0x1630 [ 47.275075] ? lock_acquire+0x16f/0x3f0 [ 47.279034] ? do_wait+0x3aa/0x9d0 [ 47.282562] ? kasan_check_write+0x14/0x20 [ 47.286780] do_wait+0x439/0x9d0 [ 47.290132] ? wait_consider_task+0x3910/0x3910 [ 47.294803] kernel_wait4+0x171/0x290 [ 47.298586] ? __ia32_sys_waitid+0x140/0x140 [ 47.303054] ? task_stopped_code+0x180/0x180 [ 47.307508] ? find_held_lock+0x35/0x130 [ 47.311565] ? __do_page_fault+0x676/0xe90 [ 47.315848] __do_sys_wait4+0x147/0x160 [ 47.319809] ? kernel_wait4+0x290/0x290 [ 47.323774] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 47.329320] ? up_read+0x1a/0x110 [ 47.332762] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 47.338283] ? __do_page_fault+0x484/0xe90 [ 47.342547] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.347289] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.352032] ? do_syscall_64+0x26/0x620 [ 47.356044] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.361398] ? do_syscall_64+0x26/0x620 [ 47.365364] __x64_sys_wait4+0x97/0xf0 [ 47.369241] do_syscall_64+0xfd/0x620 [ 47.373031] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.378206] RIP: 0033:0x40113a [ 47.381386] Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 8b 05 9e 15 2d 00 85 c0 75 36 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 d0 ff ff ff f7 [ 47.400273] RSP: 002b:00007ffded8f4c08 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 47.407978] RAX: ffffffffffffffda RBX: 0000000000001cfb RCX: 000000000040113a [ 47.415234] RDX: 0000000040000000 RSI: 00007ffded8f4c14 RDI: ffffffffffffffff [ 47.422488] RBP: 00000000006cb018 R08: 0000000000000000 R09: 00005555570dd880 [ 47.429738] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020f0 [ 47.436988] R13: 0000000000402180 R14: 0000000000000000 R15: 0000000000000000 [ 47.444246] [ 47.445855] Allocated by task 7418: [ 47.449466] save_stack+0x45/0xd0 [ 47.452908] kasan_kmalloc+0xce/0xf0 [ 47.456617] kasan_slab_alloc+0xf/0x20 [ 47.460486] kmem_cache_alloc_node+0x144/0x710 [ 47.465062] copy_process.part.0+0x1ce0/0x7a30 [ 47.469636] _do_fork+0x257/0xfd0 [ 47.473073] __x64_sys_clone+0xbf/0x150 [ 47.477033] do_syscall_64+0xfd/0x620 [ 47.480815] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.485979] [ 47.487600] Freed by task 0: [ 47.490604] save_stack+0x45/0xd0 [ 47.494042] __kasan_slab_free+0x102/0x150 [ 47.498276] kasan_slab_free+0xe/0x10 [ 47.502058] kmem_cache_free+0x86/0x260 [ 47.506015] free_task+0xdd/0x120 [ 47.509448] __put_task_struct+0x20f/0x4c0 [ 47.513665] finish_task_switch+0x52b/0x780 [ 47.517971] __schedule+0x86e/0x1dc0 [ 47.521667] schedule_idle+0x58/0x80 [ 47.525361] do_idle+0x192/0x560 [ 47.528712] cpu_startup_entry+0xc8/0xe0 [ 47.532760] rest_init+0x219/0x222 [ 47.536282] start_kernel+0x88c/0x8c5 [ 47.540167] x86_64_start_reservations+0x29/0x2b [ 47.544912] x86_64_start_kernel+0x77/0x7b [ 47.549130] secondary_startup_64+0xa4/0xb0 [ 47.553429] [ 47.555039] The buggy address belongs to the object at ffff8880a17b8580 [ 47.555039] which belongs to the cache task_struct of size 6080 [ 47.567764] The buggy address is located 1792 bytes inside of [ 47.567764] 6080-byte region [ffff8880a17b8580, ffff8880a17b9d40) [ 47.579791] The buggy address belongs to the page: [ 47.584703] page:ffffea000285ee00 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 47.594667] flags: 0x1fffc0000008100(slab|head) [ 47.599328] raw: 01fffc0000008100 ffffea00020d7e88 ffffea00026fac88 ffff88812c26d800 [ 47.607193] raw: 0000000000000000 ffff8880a17b8580 0000000100000001 0000000000000000 [ 47.615052] page dumped because: kasan: bad access detected [ 47.620741] [ 47.622349] Memory state around the buggy address: [ 47.627259] ffff8880a17b8b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.634600] ffff8880a17b8c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.641940] >ffff8880a17b8c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.649288] ^ [ 47.652634] ffff8880a17b8d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.659973] ffff8880a17b8d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.667308] ================================================================== [ 47.674650] Disabling lock debugging due to kernel taint [ 47.680078] Kernel panic - not syncing: panic_on_warn set ... [ 47.680078] [ 47.687436] CPU: 1 PID: 7418 Comm: syz-executor317 Tainted: G B 4.19.75 #0 [ 47.695750] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.705083] Call Trace: [ 47.707659] dump_stack+0x172/0x1f0 [ 47.711271] ? __change_pid+0x253/0x2f0 [ 47.715228] panic+0x263/0x507 [ 47.718404] ? __warn_printk+0xf3/0xf3 [ 47.722275] ? lock_downgrade+0x810/0x810 [ 47.726410] ? trace_hardirqs_off+0x62/0x220 [ 47.730798] ? trace_hardirqs_off+0x59/0x220 [ 47.735191] ? __change_pid+0x253/0x2f0 [ 47.739159] kasan_end_report+0x47/0x4f [ 47.743127] kasan_report.cold+0xa9/0x2ba [ 47.747260] __asan_report_load8_noabort+0x14/0x20 [ 47.752169] __change_pid+0x253/0x2f0 [ 47.755955] detach_pid+0x20/0x30 [ 47.759406] release_task+0xd65/0x1630 [ 47.763275] ? _raw_spin_unlock_irq+0x28/0x90 [ 47.767754] wait_consider_task+0x2c95/0x3910 [ 47.772234] ? release_task+0x1630/0x1630 [ 47.776364] ? lock_acquire+0x16f/0x3f0 [ 47.780320] ? do_wait+0x3aa/0x9d0 [ 47.783842] ? kasan_check_write+0x14/0x20 [ 47.788059] do_wait+0x439/0x9d0 [ 47.791409] ? wait_consider_task+0x3910/0x3910 [ 47.796075] kernel_wait4+0x171/0x290 [ 47.799858] ? __ia32_sys_waitid+0x140/0x140 [ 47.804251] ? task_stopped_code+0x180/0x180 [ 47.808644] ? find_held_lock+0x35/0x130 [ 47.812699] ? __do_page_fault+0x676/0xe90 [ 47.816919] __do_sys_wait4+0x147/0x160 [ 47.820876] ? kernel_wait4+0x290/0x290 [ 47.824842] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 47.830362] ? up_read+0x1a/0x110 [ 47.833796] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 47.839320] ? __do_page_fault+0x484/0xe90 [ 47.843542] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.848280] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.853032] ? do_syscall_64+0x26/0x620 [ 47.857005] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.862349] ? do_syscall_64+0x26/0x620 [ 47.866306] __x64_sys_wait4+0x97/0xf0 [ 47.870177] do_syscall_64+0xfd/0x620 [ 47.873963] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.879131] RIP: 0033:0x40113a [ 47.882309] Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 8b 05 9e 15 2d 00 85 c0 75 36 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 d0 ff ff ff f7 [ 47.901202] RSP: 002b:00007ffded8f4c08 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 47.908894] RAX: ffffffffffffffda RBX: 0000000000001cfb RCX: 000000000040113a [ 47.916145] RDX: 0000000040000000 RSI: 00007ffded8f4c14 RDI: ffffffffffffffff [ 47.923395] RBP: 00000000006cb018 R08: 0000000000000000 R09: 00005555570dd880 [ 47.930646] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020f0 [ 47.937897] R13: 0000000000402180 R14: 0000000000000000 R15: 0000000000000000 [ 47.946536] Kernel Offset: disabled [ 47.950162] Rebooting in 86400 seconds..