Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 39.420808] audit: type=1800 audit(1569073177.017:33): pid=7403 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 [ 39.444661] audit: type=1800 audit(1569073177.017:34): pid=7403 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: [ 40.994408] audit: type=1400 audit(1569073178.587:35): avc: denied { map } for pid=7577 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 '10.128.1.36' (ECDSA) to the list of known hosts. executing program [ 59.932192] audit: type=1400 audit(1569073197.527:36): avc: denied { map } for pid=7590 comm="syz-executor951" path="/root/syz-executor951358769" 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 [ 59.963832] ================================================================== [ 59.971338] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 59.978352] Read of size 4 at addr ffff88809018462c by task sshd/7588 [ 59.984931] [ 59.986553] CPU: 0 PID: 7588 Comm: sshd Not tainted 4.19.75 #0 [ 59.992531] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.002434] Call Trace: [ 60.005183] dump_stack+0x172/0x1f0 [ 60.008821] ? wait_consider_task+0x1b51/0x3910 [ 60.013501] print_address_description.cold+0x7c/0x20d [ 60.018786] ? wait_consider_task+0x1b51/0x3910 [ 60.023452] kasan_report.cold+0x8c/0x2ba [ 60.027600] __asan_report_load4_noabort+0x14/0x20 [ 60.032521] wait_consider_task+0x1b51/0x3910 [ 60.037009] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 60.042207] ? add_wait_queue+0x112/0x170 [ 60.046342] ? release_task+0x1630/0x1630 [ 60.050523] ? lock_acquire+0x16f/0x3f0 [ 60.054689] ? do_wait+0x3aa/0x9d0 [ 60.058233] ? kasan_check_write+0x14/0x20 [ 60.062499] do_wait+0x439/0x9d0 [ 60.065862] ? wait_consider_task+0x3910/0x3910 [ 60.070630] ? mark_held_locks+0x100/0x100 [ 60.074913] kernel_wait4+0x171/0x290 [ 60.078871] ? __ia32_sys_waitid+0x140/0x140 [ 60.083273] ? task_stopped_code+0x180/0x180 [ 60.087702] __do_sys_wait4+0x147/0x160 [ 60.091667] ? kernel_wait4+0x290/0x290 [ 60.095805] ? kasan_check_read+0x11/0x20 [ 60.100065] ? _copy_to_user+0xc9/0x120 [ 60.104035] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 60.109738] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 60.114782] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 60.119634] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 60.124431] ? do_syscall_64+0x26/0x620 [ 60.128745] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.134103] ? do_syscall_64+0x26/0x620 [ 60.138227] __x64_sys_wait4+0x97/0xf0 [ 60.142128] do_syscall_64+0xfd/0x620 [ 60.145951] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.151222] RIP: 0033:0x7fc44789da3e [ 60.154953] Code: 90 90 90 90 90 90 90 90 90 90 90 90 48 83 ec 28 8b 05 c2 eb 2d 00 85 c0 75 1d 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 48 83 c4 28 c3 89 54 24 08 48 89 74 24 10 [ 60.173844] RSP: 002b:00007fffd84a5c80 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 60.181636] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc44789da3e [ 60.188891] RDX: 0000000000000001 RSI: 00007fffd84a5cbc RDI: ffffffffffffffff [ 60.196166] RBP: 00005561f01a2c88 R08: 00007fffd84a5d80 R09: 0101010101010101 [ 60.203655] R10: 0000000000000000 R11: 0000000000000246 R12: 00005561f0a8baf0 [ 60.211006] R13: 00005561f01a0fb4 R14: 0000000000000028 R15: 00005561f01a2ca0 [ 60.218293] [ 60.219913] Allocated by task 7588: [ 60.223535] save_stack+0x45/0xd0 [ 60.226988] kasan_kmalloc+0xce/0xf0 [ 60.230684] kasan_slab_alloc+0xf/0x20 [ 60.234577] kmem_cache_alloc_node+0x144/0x710 [ 60.239340] copy_process.part.0+0x1ce0/0x7a30 [ 60.243945] _do_fork+0x257/0xfd0 [ 60.247406] __x64_sys_clone+0xbf/0x150 [ 60.251389] do_syscall_64+0xfd/0x620 [ 60.255199] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.260367] [ 60.261975] Freed by task 0: [ 60.264978] save_stack+0x45/0xd0 [ 60.268415] __kasan_slab_free+0x102/0x150 [ 60.272639] kasan_slab_free+0xe/0x10 [ 60.276502] kmem_cache_free+0x86/0x260 [ 60.280499] free_task+0xdd/0x120 [ 60.283960] __put_task_struct+0x20f/0x4c0 [ 60.288184] finish_task_switch+0x52b/0x780 [ 60.292674] __schedule+0x86e/0x1dc0 [ 60.296373] schedule_idle+0x58/0x80 [ 60.300070] do_idle+0x192/0x560 [ 60.303595] cpu_startup_entry+0xc8/0xe0 [ 60.307664] start_secondary+0x3e8/0x5b0 [ 60.311735] secondary_startup_64+0xa4/0xb0 [ 60.316046] [ 60.317706] The buggy address belongs to the object at ffff8880901841c0 [ 60.317706] which belongs to the cache task_struct of size 6080 [ 60.330464] The buggy address is located 1132 bytes inside of [ 60.330464] 6080-byte region [ffff8880901841c0, ffff888090185980) [ 60.342508] The buggy address belongs to the page: [ 60.347432] page:ffffea0002406100 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 60.357400] flags: 0x1fffc0000008100(slab|head) [ 60.362055] raw: 01fffc0000008100 ffffea0001dc5508 ffffea00023d4788 ffff88812c26d800 [ 60.369919] raw: 0000000000000000 ffff8880901841c0 0000000100000001 0000000000000000 [ 60.377915] page dumped because: kasan: bad access detected [ 60.383610] [ 60.385219] Memory state around the buggy address: [ 60.390152] ffff888090184500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.397535] ffff888090184580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.404890] >ffff888090184600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.412336] ^ [ 60.417100] ffff888090184680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.425499] ffff888090184700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.433340] ================================================================== [ 60.441763] Disabling lock debugging due to kernel taint [ 60.447690] Kernel panic - not syncing: panic_on_warn set ... [ 60.447690] [ 60.455076] CPU: 0 PID: 7588 Comm: sshd Tainted: G B 4.19.75 #0 [ 60.462469] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.471906] Call Trace: [ 60.474488] dump_stack+0x172/0x1f0 [ 60.478188] ? wait_consider_task+0x1b51/0x3910 [ 60.482846] panic+0x263/0x507 [ 60.486018] ? __warn_printk+0xf3/0xf3 [ 60.489886] ? retint_kernel+0x2d/0x2d [ 60.493779] ? trace_hardirqs_on+0x5e/0x220 [ 60.498097] ? wait_consider_task+0x1b51/0x3910 [ 60.502782] kasan_end_report+0x47/0x4f [ 60.507059] kasan_report.cold+0xa9/0x2ba [ 60.511352] __asan_report_load4_noabort+0x14/0x20 [ 60.516402] wait_consider_task+0x1b51/0x3910 [ 60.521072] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 60.526420] ? add_wait_queue+0x112/0x170 [ 60.530560] ? release_task+0x1630/0x1630 [ 60.534698] ? lock_acquire+0x16f/0x3f0 [ 60.538653] ? do_wait+0x3aa/0x9d0 [ 60.542191] ? kasan_check_write+0x14/0x20 [ 60.546415] do_wait+0x439/0x9d0 [ 60.549791] ? wait_consider_task+0x3910/0x3910 [ 60.554560] ? mark_held_locks+0x100/0x100 [ 60.558984] kernel_wait4+0x171/0x290 [ 60.562929] ? __ia32_sys_waitid+0x140/0x140 [ 60.567358] ? task_stopped_code+0x180/0x180 [ 60.571788] __do_sys_wait4+0x147/0x160 [ 60.575759] ? kernel_wait4+0x290/0x290 [ 60.579927] ? kasan_check_read+0x11/0x20 [ 60.584123] ? _copy_to_user+0xc9/0x120 [ 60.588110] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 60.593660] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 60.598668] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 60.603859] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 60.608731] ? do_syscall_64+0x26/0x620 [ 60.612875] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.618241] ? do_syscall_64+0x26/0x620 [ 60.622216] __x64_sys_wait4+0x97/0xf0 [ 60.626093] do_syscall_64+0xfd/0x620 [ 60.629894] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.635168] RIP: 0033:0x7fc44789da3e [ 60.638873] Code: 90 90 90 90 90 90 90 90 90 90 90 90 48 83 ec 28 8b 05 c2 eb 2d 00 85 c0 75 1d 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 48 83 c4 28 c3 89 54 24 08 48 89 74 24 10 [ 60.657774] RSP: 002b:00007fffd84a5c80 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 60.665571] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc44789da3e [ 60.672911] RDX: 0000000000000001 RSI: 00007fffd84a5cbc RDI: ffffffffffffffff [ 60.680176] RBP: 00005561f01a2c88 R08: 00007fffd84a5d80 R09: 0101010101010101 [ 60.687431] R10: 0000000000000000 R11: 0000000000000246 R12: 00005561f0a8baf0 [ 60.694700] R13: 00005561f01a0fb4 R14: 0000000000000028 R15: 00005561f01a2ca0 [ 60.704212] Kernel Offset: disabled [ 60.707869] Rebooting in 86400 seconds..