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. [ 37.461391] audit: type=1800 audit(1569056199.371:33): pid=7343 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 [ 37.486744] audit: type=1800 audit(1569056199.381:34): pid=7343 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: [ 39.790615] audit: type=1400 audit(1569056201.701:35): avc: denied { map } for pid=7518 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 '10.128.10.23' (ECDSA) to the list of known hosts. executing program [ 46.345235] audit: type=1400 audit(1569056208.261:36): avc: denied { map } for pid=7531 comm="syz-executor173" path="/root/syz-executor173597656" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 46.376674] ================================================================== [ 46.384132] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 46.391157] Read of size 4 at addr ffff88809aed44ec by task sshd/7529 [ 46.397719] [ 46.399352] CPU: 0 PID: 7529 Comm: sshd Not tainted 4.19.75 #0 [ 46.405307] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.414657] Call Trace: [ 46.417242] dump_stack+0x172/0x1f0 [ 46.420898] ? wait_consider_task+0x1b51/0x3910 [ 46.425573] print_address_description.cold+0x7c/0x20d [ 46.430868] ? wait_consider_task+0x1b51/0x3910 [ 46.435625] kasan_report.cold+0x8c/0x2ba [ 46.439769] __asan_report_load4_noabort+0x14/0x20 [ 46.444689] wait_consider_task+0x1b51/0x3910 [ 46.449184] ? mark_held_locks+0x100/0x100 [ 46.453410] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 46.459998] ? add_wait_queue+0x112/0x170 [ 46.464140] ? release_task+0x1630/0x1630 [ 46.468276] ? lock_acquire+0x16f/0x3f0 [ 46.472241] ? do_wait+0x3aa/0x9d0 [ 46.475785] ? kasan_check_write+0x14/0x20 [ 46.480013] do_wait+0x439/0x9d0 [ 46.483385] ? wait_consider_task+0x3910/0x3910 [ 46.488046] ? mark_held_locks+0x100/0x100 [ 46.492274] kernel_wait4+0x171/0x290 [ 46.496068] ? __ia32_sys_waitid+0x140/0x140 [ 46.500470] ? task_stopped_code+0x180/0x180 [ 46.504882] __do_sys_wait4+0x147/0x160 [ 46.508869] ? kernel_wait4+0x290/0x290 [ 46.512850] ? kasan_check_read+0x11/0x20 [ 46.516994] ? _copy_to_user+0xc9/0x120 [ 46.520980] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.526512] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 46.531520] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.536978] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.547636] ? do_syscall_64+0x26/0x620 [ 46.551612] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.556963] ? do_syscall_64+0x26/0x620 [ 46.560932] __x64_sys_wait4+0x97/0xf0 [ 46.564808] do_syscall_64+0xfd/0x620 [ 46.568623] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.573802] RIP: 0033:0x7f319e1c3a3e [ 46.577504] 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 [ 46.596398] RSP: 002b:00007fff64d580a0 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 46.604097] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f319e1c3a3e [ 46.611372] RDX: 0000000000000001 RSI: 00007fff64d580dc RDI: ffffffffffffffff [ 46.618644] RBP: 00005559b70cac88 R08: 00007fff64d581a0 R09: 0101010101010101 [ 46.625926] R10: 0000000000000000 R11: 0000000000000246 R12: 00005559b7fd7af0 [ 46.633197] R13: 00005559b70c8fb4 R14: 0000000000000028 R15: 00005559b70caca0 [ 46.640481] [ 46.642093] Allocated by task 7529: [ 46.645722] save_stack+0x45/0xd0 [ 46.649161] kasan_kmalloc+0xce/0xf0 [ 46.652863] kasan_slab_alloc+0xf/0x20 [ 46.656736] kmem_cache_alloc_node+0x144/0x710 [ 46.661345] copy_process.part.0+0x1ce0/0x7a30 [ 46.665927] _do_fork+0x257/0xfd0 [ 46.669369] __x64_sys_clone+0xbf/0x150 [ 46.673343] do_syscall_64+0xfd/0x620 [ 46.677132] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.682304] [ 46.683917] Freed by task 7529: [ 46.687186] save_stack+0x45/0xd0 [ 46.690624] __kasan_slab_free+0x102/0x150 [ 46.694858] kasan_slab_free+0xe/0x10 [ 46.698642] kmem_cache_free+0x86/0x260 [ 46.702606] free_task+0xdd/0x120 [ 46.706051] __put_task_struct+0x20f/0x4c0 [ 46.710292] finish_task_switch+0x52b/0x780 [ 46.714635] __schedule+0x86e/0x1dc0 [ 46.718334] schedule+0x92/0x1c0 [ 46.721696] schedule_hrtimeout_range_clock+0x1b1/0x380 [ 46.727058] schedule_hrtimeout_range+0x2b/0x40 [ 46.731715] poll_schedule_timeout.constprop.0+0x11a/0x200 [ 46.737360] do_select+0x12bd/0x16d0 [ 46.741062] core_sys_select+0x564/0x870 [ 46.745111] kern_select+0x15d/0x1e0 [ 46.748813] __x64_sys_select+0xbe/0x150 [ 46.752867] do_syscall_64+0xfd/0x620 [ 46.756663] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.761833] [ 46.763456] The buggy address belongs to the object at ffff88809aed4080 [ 46.763456] which belongs to the cache task_struct of size 6080 [ 46.776191] The buggy address is located 1132 bytes inside of [ 46.776191] 6080-byte region [ffff88809aed4080, ffff88809aed5840) [ 46.788227] The buggy address belongs to the page: [ 46.793144] page:ffffea00026bb500 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 46.803102] flags: 0x1fffc0000008100(slab|head) [ 46.807757] raw: 01fffc0000008100 ffffea00026b7188 ffffea0002687008 ffff88812c26d800 [ 46.815639] raw: 0000000000000000 ffff88809aed4080 0000000100000001 0000000000000000 [ 46.823504] page dumped because: kasan: bad access detected [ 46.829211] [ 46.830820] Memory state around the buggy address: [ 46.835738] ffff88809aed4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.843092] ffff88809aed4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.850445] >ffff88809aed4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.857936] ^ [ 46.864682] ffff88809aed4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.872048] ffff88809aed4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.879402] ================================================================== [ 46.886744] Disabling lock debugging due to kernel taint [ 46.892338] Kernel panic - not syncing: panic_on_warn set ... [ 46.892338] [ 46.899726] CPU: 0 PID: 7529 Comm: sshd Tainted: G B 4.19.75 #0 [ 46.907086] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.916429] Call Trace: [ 46.919010] dump_stack+0x172/0x1f0 [ 46.922634] ? wait_consider_task+0x1b51/0x3910 [ 46.927292] panic+0x263/0x507 [ 46.930473] ? __warn_printk+0xf3/0xf3 [ 46.934359] ? retint_kernel+0x2d/0x2d [ 46.938255] ? trace_hardirqs_on+0x5e/0x220 [ 46.942594] ? wait_consider_task+0x1b51/0x3910 [ 46.947259] kasan_end_report+0x47/0x4f [ 46.951273] kasan_report.cold+0xa9/0x2ba [ 46.955422] __asan_report_load4_noabort+0x14/0x20 [ 46.960343] wait_consider_task+0x1b51/0x3910 [ 46.964831] ? mark_held_locks+0x100/0x100 [ 46.969064] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 46.974154] ? add_wait_queue+0x112/0x170 [ 46.978292] ? release_task+0x1630/0x1630 [ 46.982439] ? lock_acquire+0x16f/0x3f0 [ 46.986403] ? do_wait+0x3aa/0x9d0 [ 46.989933] ? kasan_check_write+0x14/0x20 [ 46.994154] do_wait+0x439/0x9d0 [ 46.997516] ? wait_consider_task+0x3910/0x3910 [ 47.002171] ? mark_held_locks+0x100/0x100 [ 47.006475] kernel_wait4+0x171/0x290 [ 47.010275] ? __ia32_sys_waitid+0x140/0x140 [ 47.014737] ? task_stopped_code+0x180/0x180 [ 47.019138] __do_sys_wait4+0x147/0x160 [ 47.023098] ? kernel_wait4+0x290/0x290 [ 47.027060] ? kasan_check_read+0x11/0x20 [ 47.031196] ? _copy_to_user+0xc9/0x120 [ 47.035249] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.040792] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 47.045821] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.050573] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.055331] ? do_syscall_64+0x26/0x620 [ 47.059291] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.064639] ? do_syscall_64+0x26/0x620 [ 47.068605] __x64_sys_wait4+0x97/0xf0 [ 47.072480] do_syscall_64+0xfd/0x620 [ 47.076277] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.081452] RIP: 0033:0x7f319e1c3a3e [ 47.085153] 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 [ 47.104046] RSP: 002b:00007fff64d580a0 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 47.111743] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f319e1c3a3e [ 47.119001] RDX: 0000000000000001 RSI: 00007fff64d580dc RDI: ffffffffffffffff [ 47.126265] RBP: 00005559b70cac88 R08: 00007fff64d581a0 R09: 0101010101010101 [ 47.133533] R10: 0000000000000000 R11: 0000000000000246 R12: 00005559b7fd7af0 [ 47.140844] R13: 00005559b70c8fb4 R14: 0000000000000028 R15: 00005559b70caca0 [ 47.149532] Kernel Offset: disabled [ 47.153181] Rebooting in 86400 seconds..