[ 38.743774] audit: type=1800 audit(1569889700.748:31): pid=7441 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [ 38.784001] audit: type=1800 audit(1569889700.748:32): pid=7441 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2450 res=0 [....] 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.75' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 47.204524] kauditd_printk_skb: 3 callbacks suppressed [ 47.204545] audit: type=1400 audit(1569889709.288:36): avc: denied { map } for pid=7627 comm="syz-executor250" path="/root/syz-executor250923381" 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 [ 47.240307] ================================================================== [ 47.247771] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 47.254876] Read of size 4 at addr ffff88807d0ce72c by task sshd/7625 [ 47.261702] [ 47.263465] CPU: 0 PID: 7625 Comm: sshd Not tainted 4.19.75 #0 [ 47.269434] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.278778] Call Trace: [ 47.281365] dump_stack+0x172/0x1f0 [ 47.284997] ? wait_consider_task+0x1b51/0x3910 [ 47.289704] print_address_description.cold+0x7c/0x20d [ 47.295332] ? wait_consider_task+0x1b51/0x3910 [ 47.300348] kasan_report.cold+0x8c/0x2ba [ 47.304599] __asan_report_load4_noabort+0x14/0x20 [ 47.309720] wait_consider_task+0x1b51/0x3910 [ 47.314350] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 47.319476] ? add_wait_queue+0x112/0x170 [ 47.323633] ? release_task+0x1630/0x1630 [ 47.327786] ? lock_acquire+0x16f/0x3f0 [ 47.331743] ? do_wait+0x3aa/0x9d0 [ 47.335362] ? kasan_check_write+0x14/0x20 [ 47.339595] do_wait+0x439/0x9d0 [ 47.342955] ? wait_consider_task+0x3910/0x3910 [ 47.347637] ? mark_held_locks+0x100/0x100 [ 47.352657] kernel_wait4+0x171/0x290 [ 47.356467] ? __ia32_sys_waitid+0x140/0x140 [ 47.360978] ? task_stopped_code+0x180/0x180 [ 47.365400] __do_sys_wait4+0x147/0x160 [ 47.369366] ? kernel_wait4+0x290/0x290 [ 47.373332] ? kasan_check_read+0x11/0x20 [ 47.377555] ? _copy_to_user+0xc9/0x120 [ 47.381518] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.387047] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 47.392089] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.396847] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.402554] ? do_syscall_64+0x26/0x620 [ 47.406518] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.411970] ? do_syscall_64+0x26/0x620 [ 47.415942] __x64_sys_wait4+0x97/0xf0 [ 47.419833] do_syscall_64+0xfd/0x620 [ 47.423622] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.428795] RIP: 0033:0x7f8a4d657a3e [ 47.432493] 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 [ 47.451394] RSP: 002b:00007ffd1abec9c0 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 47.459106] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8a4d657a3e [ 47.466375] RDX: 0000000000000001 RSI: 00007ffd1abec9fc RDI: ffffffffffffffff [ 47.473631] RBP: 000055b85e9f7c88 R08: 00007ffd1abecac0 R09: 0101010101010101 [ 47.480901] R10: 0000000000000000 R11: 0000000000000246 R12: 000055b85f578db0 [ 47.488188] R13: 000055b85e9f5fb4 R14: 0000000000000028 R15: 000055b85e9f7ca0 [ 47.495467] [ 47.497092] Allocated by task 7625: [ 47.500712] save_stack+0x45/0xd0 [ 47.505022] kasan_kmalloc+0xce/0xf0 [ 47.508721] kasan_slab_alloc+0xf/0x20 [ 47.512594] kmem_cache_alloc_node+0x144/0x710 [ 47.517162] copy_process.part.0+0x1ce0/0x7a30 [ 47.521897] _do_fork+0x257/0xfd0 [ 47.525335] __x64_sys_clone+0xbf/0x150 [ 47.529307] do_syscall_64+0xfd/0x620 [ 47.533104] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.538282] [ 47.539912] Freed by task 0: [ 47.542915] save_stack+0x45/0xd0 [ 47.546368] __kasan_slab_free+0x102/0x150 [ 47.550585] kasan_slab_free+0xe/0x10 [ 47.554367] kmem_cache_free+0x86/0x260 [ 47.558335] free_task+0xdd/0x120 [ 47.561769] __put_task_struct+0x20f/0x4c0 [ 47.565989] finish_task_switch+0x52b/0x780 [ 47.570306] __schedule+0x86e/0x1dc0 [ 47.574015] schedule_idle+0x58/0x80 [ 47.577712] do_idle+0x192/0x560 [ 47.581060] cpu_startup_entry+0xc8/0xe0 [ 47.585460] start_secondary+0x3e8/0x5b0 [ 47.589504] secondary_startup_64+0xa4/0xb0 [ 47.593813] [ 47.595438] The buggy address belongs to the object at ffff88807d0ce2c0 [ 47.595438] which belongs to the cache task_struct of size 6080 [ 47.608167] The buggy address is located 1132 bytes inside of [ 47.608167] 6080-byte region [ffff88807d0ce2c0, ffff88807d0cfa80) [ 47.620196] The buggy address belongs to the page: [ 47.625110] page:ffffea0001f43380 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 47.635073] flags: 0x1fffc0000008100(slab|head) [ 47.639825] raw: 01fffc0000008100 ffffea0002455a08 ffffea0001f6b208 ffff88812c26d800 [ 47.647691] raw: 0000000000000000 ffff88807d0ce2c0 0000000100000001 0000000000000000 [ 47.655648] page dumped because: kasan: bad access detected [ 47.661335] [ 47.662942] Memory state around the buggy address: [ 47.667855] ffff88807d0ce600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.675197] ffff88807d0ce680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.682541] >ffff88807d0ce700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.690046] ^ [ 47.694707] ffff88807d0ce780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.702180] ffff88807d0ce800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.709537] ================================================================== [ 47.716889] Disabling lock debugging due to kernel taint [ 47.722410] Kernel panic - not syncing: panic_on_warn set ... [ 47.722410] [ 47.729802] CPU: 0 PID: 7625 Comm: sshd Tainted: G B 4.19.75 #0 [ 47.737329] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.746675] Call Trace: [ 47.749253] dump_stack+0x172/0x1f0 [ 47.752864] ? wait_consider_task+0x1b51/0x3910 [ 47.757512] panic+0x263/0x507 [ 47.760688] ? __warn_printk+0xf3/0xf3 [ 47.765515] ? retint_kernel+0x2d/0x2d [ 47.769488] ? trace_hardirqs_on+0x5e/0x220 [ 47.773804] ? wait_consider_task+0x1b51/0x3910 [ 47.778552] kasan_end_report+0x47/0x4f [ 47.782593] kasan_report.cold+0xa9/0x2ba [ 47.786736] __asan_report_load4_noabort+0x14/0x20 [ 47.791657] wait_consider_task+0x1b51/0x3910 [ 47.796153] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 47.801240] ? add_wait_queue+0x112/0x170 [ 47.805370] ? release_task+0x1630/0x1630 [ 47.809542] ? lock_acquire+0x16f/0x3f0 [ 47.813497] ? do_wait+0x3aa/0x9d0 [ 47.817031] ? kasan_check_write+0x14/0x20 [ 47.821258] do_wait+0x439/0x9d0 [ 47.824639] ? wait_consider_task+0x3910/0x3910 [ 47.829286] ? mark_held_locks+0x100/0x100 [ 47.833511] kernel_wait4+0x171/0x290 [ 47.837408] ? __ia32_sys_waitid+0x140/0x140 [ 47.841843] ? task_stopped_code+0x180/0x180 [ 47.846245] __do_sys_wait4+0x147/0x160 [ 47.850232] ? kernel_wait4+0x290/0x290 [ 47.854211] ? kasan_check_read+0x11/0x20 [ 47.858347] ? _copy_to_user+0xc9/0x120 [ 47.862875] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.871292] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 47.877214] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.882588] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.887571] ? do_syscall_64+0x26/0x620 [ 47.891690] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.897176] ? do_syscall_64+0x26/0x620 [ 47.901143] __x64_sys_wait4+0x97/0xf0 [ 47.905028] do_syscall_64+0xfd/0x620 [ 47.908814] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.913983] RIP: 0033:0x7f8a4d657a3e [ 47.917680] 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 [ 47.936603] RSP: 002b:00007ffd1abec9c0 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 47.944300] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8a4d657a3e [ 47.951551] RDX: 0000000000000001 RSI: 00007ffd1abec9fc RDI: ffffffffffffffff [ 47.958813] RBP: 000055b85e9f7c88 R08: 00007ffd1abecac0 R09: 0101010101010101 [ 47.966066] R10: 0000000000000000 R11: 0000000000000246 R12: 000055b85f578db0 [ 47.973328] R13: 000055b85e9f5fb4 R14: 0000000000000028 R15: 000055b85e9f7ca0 [ 47.982085] Kernel Offset: disabled [ 47.985724] Rebooting in 86400 seconds..