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. [ 33.943334] kauditd_printk_skb: 9 callbacks suppressed [ 33.943345] audit: type=1800 audit(1569071705.977:33): pid=7095 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 [ 33.969952] audit: type=1800 audit(1569071705.977:34): pid=7095 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: [ 42.559555] audit: type=1400 audit(1569071714.587:35): avc: denied { map } for pid=7272 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 '10.128.1.43' (ECDSA) to the list of known hosts. executing program [ 48.997931] audit: type=1400 audit(1569071721.027:36): avc: denied { map } for pid=7284 comm="syz-executor260" path="/root/syz-executor260895714" 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 [ 49.026830] ================================================================== [ 49.034253] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 49.041275] Read of size 4 at addr ffff88809c16852c by task sshd/7282 [ 49.047827] [ 49.049437] CPU: 1 PID: 7282 Comm: sshd Not tainted 4.19.75 #0 [ 49.055380] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.064721] Call Trace: [ 49.067292] dump_stack+0x172/0x1f0 [ 49.070906] ? wait_consider_task+0x1b51/0x3910 [ 49.075556] print_address_description.cold+0x7c/0x20d [ 49.080817] ? wait_consider_task+0x1b51/0x3910 [ 49.085480] kasan_report.cold+0x8c/0x2ba [ 49.089609] __asan_report_load4_noabort+0x14/0x20 [ 49.094514] wait_consider_task+0x1b51/0x3910 [ 49.098991] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 49.104081] ? add_wait_queue+0x112/0x170 [ 49.108212] ? release_task+0x1630/0x1630 [ 49.112362] ? lock_acquire+0x16f/0x3f0 [ 49.116315] ? do_wait+0x3aa/0x9d0 [ 49.119833] ? kasan_check_write+0x14/0x20 [ 49.124042] do_wait+0x439/0x9d0 [ 49.127400] ? wait_consider_task+0x3910/0x3910 [ 49.132058] ? mark_held_locks+0x100/0x100 [ 49.136297] kernel_wait4+0x171/0x290 [ 49.140078] ? __ia32_sys_waitid+0x140/0x140 [ 49.144496] ? task_stopped_code+0x180/0x180 [ 49.148887] __do_sys_wait4+0x147/0x160 [ 49.152838] ? kernel_wait4+0x290/0x290 [ 49.156803] ? kasan_check_read+0x11/0x20 [ 49.160927] ? _copy_to_user+0xc9/0x120 [ 49.164878] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 49.170389] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 49.175384] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 49.180117] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 49.184849] ? do_syscall_64+0x26/0x620 [ 49.188801] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.194142] ? do_syscall_64+0x26/0x620 [ 49.198095] __x64_sys_wait4+0x97/0xf0 [ 49.201958] do_syscall_64+0xfd/0x620 [ 49.205778] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.211012] RIP: 0033:0x7f24662b3a3e [ 49.214737] 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 [ 49.233732] RSP: 002b:00007ffc39d77a70 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 49.241418] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f24662b3a3e [ 49.248662] RDX: 0000000000000001 RSI: 00007ffc39d77aac RDI: ffffffffffffffff [ 49.255908] RBP: 0000559d69b1ac88 R08: 00007ffc39d77b70 R09: 0101010101010101 [ 49.263178] R10: 0000000000000000 R11: 0000000000000246 R12: 0000559d6a724db0 [ 49.270422] R13: 0000559d69b18fb4 R14: 0000000000000028 R15: 0000559d69b1aca0 [ 49.277670] [ 49.279279] Allocated by task 7282: [ 49.282886] save_stack+0x45/0xd0 [ 49.286329] kasan_kmalloc+0xce/0xf0 [ 49.290032] kasan_slab_alloc+0xf/0x20 [ 49.293896] kmem_cache_alloc_node+0x144/0x710 [ 49.298453] copy_process.part.0+0x1ce0/0x7a30 [ 49.303006] _do_fork+0x257/0xfd0 [ 49.306434] __x64_sys_clone+0xbf/0x150 [ 49.310383] do_syscall_64+0xfd/0x620 [ 49.314166] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.319414] [ 49.321014] Freed by task 0: [ 49.324029] save_stack+0x45/0xd0 [ 49.327489] __kasan_slab_free+0x102/0x150 [ 49.331697] kasan_slab_free+0xe/0x10 [ 49.335471] kmem_cache_free+0x86/0x260 [ 49.339419] free_task+0xdd/0x120 [ 49.342858] __put_task_struct+0x20f/0x4c0 [ 49.347068] finish_task_switch+0x52b/0x780 [ 49.351364] __schedule+0x86e/0x1dc0 [ 49.355052] schedule_idle+0x58/0x80 [ 49.358757] do_idle+0x192/0x560 [ 49.362099] cpu_startup_entry+0xc8/0xe0 [ 49.366135] rest_init+0x219/0x222 [ 49.369742] start_kernel+0x88c/0x8c5 [ 49.373527] x86_64_start_reservations+0x29/0x2b [ 49.378258] x86_64_start_kernel+0x77/0x7b [ 49.382495] secondary_startup_64+0xa4/0xb0 [ 49.386809] [ 49.388424] The buggy address belongs to the object at ffff88809c1680c0 [ 49.388424] which belongs to the cache task_struct of size 6080 [ 49.401145] The buggy address is located 1132 bytes inside of [ 49.401145] 6080-byte region [ffff88809c1680c0, ffff88809c169880) [ 49.413187] The buggy address belongs to the page: [ 49.418114] page:ffffea0002705a00 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 49.428061] flags: 0x1fffc0000008100(slab|head) [ 49.432716] raw: 01fffc0000008100 ffffea00027d0788 ffffea0002850808 ffff88812c26d800 [ 49.440588] raw: 0000000000000000 ffff88809c1680c0 0000000100000001 0000000000000000 [ 49.448442] page dumped because: kasan: bad access detected [ 49.454124] [ 49.455726] Memory state around the buggy address: [ 49.460652] ffff88809c168400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.468002] ffff88809c168480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.475337] >ffff88809c168500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.482679] ^ [ 49.487345] ffff88809c168580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.494699] ffff88809c168600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.502055] ================================================================== [ 49.509383] Disabling lock debugging due to kernel taint [ 49.514961] Kernel panic - not syncing: panic_on_warn set ... [ 49.514961] [ 49.522318] CPU: 1 PID: 7282 Comm: sshd Tainted: G B 4.19.75 #0 [ 49.529664] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.538990] Call Trace: [ 49.541550] dump_stack+0x172/0x1f0 [ 49.545167] ? wait_consider_task+0x1b51/0x3910 [ 49.549811] panic+0x263/0x507 [ 49.553008] ? __warn_printk+0xf3/0xf3 [ 49.556887] ? retint_kernel+0x2d/0x2d [ 49.560758] ? trace_hardirqs_on+0x5e/0x220 [ 49.565053] ? wait_consider_task+0x1b51/0x3910 [ 49.569698] kasan_end_report+0x47/0x4f [ 49.573645] kasan_report.cold+0xa9/0x2ba [ 49.577768] __asan_report_load4_noabort+0x14/0x20 [ 49.582673] wait_consider_task+0x1b51/0x3910 [ 49.587150] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 49.592229] ? add_wait_queue+0x112/0x170 [ 49.596397] ? release_task+0x1630/0x1630 [ 49.600519] ? lock_acquire+0x16f/0x3f0 [ 49.604468] ? do_wait+0x3aa/0x9d0 [ 49.607985] ? kasan_check_write+0x14/0x20 [ 49.612207] do_wait+0x439/0x9d0 [ 49.615552] ? wait_consider_task+0x3910/0x3910 [ 49.620207] ? mark_held_locks+0x100/0x100 [ 49.624417] kernel_wait4+0x171/0x290 [ 49.628195] ? __ia32_sys_waitid+0x140/0x140 [ 49.632589] ? task_stopped_code+0x180/0x180 [ 49.636990] __do_sys_wait4+0x147/0x160 [ 49.640960] ? kernel_wait4+0x290/0x290 [ 49.644925] ? kasan_check_read+0x11/0x20 [ 49.649057] ? _copy_to_user+0xc9/0x120 [ 49.653008] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 49.658525] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 49.663542] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 49.668318] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 49.673063] ? do_syscall_64+0x26/0x620 [ 49.677026] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.682386] ? do_syscall_64+0x26/0x620 [ 49.686337] __x64_sys_wait4+0x97/0xf0 [ 49.690221] do_syscall_64+0xfd/0x620 [ 49.693997] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.699169] RIP: 0033:0x7f24662b3a3e [ 49.702857] 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 [ 49.721734] RSP: 002b:00007ffc39d77a70 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 49.729418] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f24662b3a3e [ 49.736661] RDX: 0000000000000001 RSI: 00007ffc39d77aac RDI: ffffffffffffffff [ 49.743916] RBP: 0000559d69b1ac88 R08: 00007ffc39d77b70 R09: 0101010101010101 [ 49.751158] R10: 0000000000000000 R11: 0000000000000246 R12: 0000559d6a724db0 [ 49.758401] R13: 0000559d69b18fb4 R14: 0000000000000028 R15: 0000559d69b1aca0 [ 49.766982] Kernel Offset: disabled [ 49.770607] Rebooting in 86400 seconds..