Warning: Permanently added '10.128.0.118' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 47.966043] kauditd_printk_skb: 2 callbacks suppressed [ 47.966060] audit: type=1400 audit(1569198715.203:36): avc: denied { map } for pid=7615 comm="syz-executor171" path="/root/syz-executor171749519" 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 [ 48.001737] ================================================================== [ 48.009233] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 48.016241] Read of size 4 at addr ffff888093f8672c by task sshd/7613 [ 48.022799] [ 48.024425] CPU: 1 PID: 7613 Comm: sshd Not tainted 4.19.75 #0 [ 48.030532] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.039873] Call Trace: [ 48.042457] dump_stack+0x172/0x1f0 [ 48.046079] ? wait_consider_task+0x1b51/0x3910 [ 48.050741] print_address_description.cold+0x7c/0x20d [ 48.056031] ? wait_consider_task+0x1b51/0x3910 [ 48.060688] kasan_report.cold+0x8c/0x2ba [ 48.064828] __asan_report_load4_noabort+0x14/0x20 [ 48.069744] wait_consider_task+0x1b51/0x3910 [ 48.074239] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 48.079326] ? add_wait_queue+0x112/0x170 [ 48.083467] ? release_task+0x1630/0x1630 [ 48.087622] ? lock_acquire+0x16f/0x3f0 [ 48.091589] ? do_wait+0x3aa/0x9d0 [ 48.095119] ? kasan_check_write+0x14/0x20 [ 48.099340] do_wait+0x439/0x9d0 [ 48.102693] ? wait_consider_task+0x3910/0x3910 [ 48.107343] ? mark_held_locks+0x100/0x100 [ 48.111565] kernel_wait4+0x171/0x290 [ 48.115351] ? __ia32_sys_waitid+0x140/0x140 [ 48.119745] ? task_stopped_code+0x180/0x180 [ 48.124149] __do_sys_wait4+0x147/0x160 [ 48.128121] ? kernel_wait4+0x290/0x290 [ 48.132088] ? kasan_check_read+0x11/0x20 [ 48.136221] ? _copy_to_user+0xc9/0x120 [ 48.140183] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 48.145725] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 48.150732] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.155473] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.160212] ? do_syscall_64+0x26/0x620 [ 48.164187] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.169556] ? do_syscall_64+0x26/0x620 [ 48.173546] __x64_sys_wait4+0x97/0xf0 [ 48.177427] do_syscall_64+0xfd/0x620 [ 48.181241] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.186413] RIP: 0033:0x7f69b7305a3e [ 48.190131] 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 [ 48.209075] RSP: 002b:00007ffc99b96990 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 48.216778] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f69b7305a3e [ 48.224032] RDX: 0000000000000001 RSI: 00007ffc99b969cc RDI: ffffffffffffffff [ 48.231287] RBP: 000055e67ea3ac88 R08: 00007ffc99b96a90 R09: 0101010101010101 [ 48.238540] R10: 0000000000000000 R11: 0000000000000246 R12: 000055e67f9c2c00 [ 48.245802] R13: 000055e67ea38fb4 R14: 0000000000000028 R15: 000055e67ea3aca0 [ 48.253064] [ 48.254675] Allocated by task 7613: [ 48.258293] save_stack+0x45/0xd0 [ 48.261726] kasan_kmalloc+0xce/0xf0 [ 48.265422] kasan_slab_alloc+0xf/0x20 [ 48.269292] kmem_cache_alloc_node+0x144/0x710 [ 48.273864] copy_process.part.0+0x1ce0/0x7a30 [ 48.278435] _do_fork+0x257/0xfd0 [ 48.281870] __x64_sys_clone+0xbf/0x150 [ 48.285842] do_syscall_64+0xfd/0x620 [ 48.289630] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.294796] [ 48.296404] Freed by task 0: [ 48.299419] save_stack+0x45/0xd0 [ 48.302868] __kasan_slab_free+0x102/0x150 [ 48.307097] kasan_slab_free+0xe/0x10 [ 48.310888] kmem_cache_free+0x86/0x260 [ 48.314875] free_task+0xdd/0x120 [ 48.318306] __put_task_struct+0x20f/0x4c0 [ 48.322530] finish_task_switch+0x52b/0x780 [ 48.326855] __schedule+0x86e/0x1dc0 [ 48.330550] schedule_idle+0x58/0x80 [ 48.334242] do_idle+0x192/0x560 [ 48.337587] cpu_startup_entry+0xc8/0xe0 [ 48.341627] rest_init+0x219/0x222 [ 48.345160] start_kernel+0x88c/0x8c5 [ 48.348946] x86_64_start_reservations+0x29/0x2b [ 48.354728] x86_64_start_kernel+0x77/0x7b [ 48.358945] secondary_startup_64+0xa4/0xb0 [ 48.363246] [ 48.364857] The buggy address belongs to the object at ffff888093f862c0 [ 48.364857] which belongs to the cache task_struct of size 6080 [ 48.377582] The buggy address is located 1132 bytes inside of [ 48.377582] 6080-byte region [ffff888093f862c0, ffff888093f87a80) [ 48.389622] The buggy address belongs to the page: [ 48.394539] page:ffffea00024fe180 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 48.404493] flags: 0x1fffc0000008100(slab|head) [ 48.409145] raw: 01fffc0000008100 ffffea00027fe908 ffffea000248cd08 ffff88812c26d800 [ 48.417007] raw: 0000000000000000 ffff888093f862c0 0000000100000001 0000000000000000 [ 48.424873] page dumped because: kasan: bad access detected [ 48.430561] [ 48.432171] Memory state around the buggy address: [ 48.437086] ffff888093f86600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.444434] ffff888093f86680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.451785] >ffff888093f86700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.459121] ^ [ 48.463768] ffff888093f86780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.471110] ffff888093f86800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.478449] ================================================================== [ 48.485785] Disabling lock debugging due to kernel taint [ 48.491431] Kernel panic - not syncing: panic_on_warn set ... [ 48.491431] [ 48.498872] CPU: 1 PID: 7613 Comm: sshd Tainted: G B 4.19.75 #0 [ 48.506220] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.515558] Call Trace: [ 48.518138] dump_stack+0x172/0x1f0 [ 48.521770] ? wait_consider_task+0x1b51/0x3910 [ 48.526422] panic+0x263/0x507 [ 48.529598] ? __warn_printk+0xf3/0xf3 [ 48.533472] ? retint_kernel+0x2d/0x2d [ 48.537349] ? trace_hardirqs_on+0x5e/0x220 [ 48.541653] ? wait_consider_task+0x1b51/0x3910 [ 48.546315] kasan_end_report+0x47/0x4f [ 48.550270] kasan_report.cold+0xa9/0x2ba [ 48.554400] __asan_report_load4_noabort+0x14/0x20 [ 48.559310] wait_consider_task+0x1b51/0x3910 [ 48.563802] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 48.568904] ? add_wait_queue+0x112/0x170 [ 48.573044] ? release_task+0x1630/0x1630 [ 48.577201] ? lock_acquire+0x16f/0x3f0 [ 48.581157] ? do_wait+0x3aa/0x9d0 [ 48.584687] ? kasan_check_write+0x14/0x20 [ 48.588902] do_wait+0x439/0x9d0 [ 48.592262] ? wait_consider_task+0x3910/0x3910 [ 48.596913] ? mark_held_locks+0x100/0x100 [ 48.601131] kernel_wait4+0x171/0x290 [ 48.604913] ? __ia32_sys_waitid+0x140/0x140 [ 48.609311] ? task_stopped_code+0x180/0x180 [ 48.613704] __do_sys_wait4+0x147/0x160 [ 48.617670] ? kernel_wait4+0x290/0x290 [ 48.621628] ? kasan_check_read+0x11/0x20 [ 48.625760] ? _copy_to_user+0xc9/0x120 [ 48.629905] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 48.635428] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 48.640428] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.645162] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.649905] ? do_syscall_64+0x26/0x620 [ 48.653868] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.659212] ? do_syscall_64+0x26/0x620 [ 48.663169] __x64_sys_wait4+0x97/0xf0 [ 48.667042] do_syscall_64+0xfd/0x620 [ 48.670827] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.676000] RIP: 0033:0x7f69b7305a3e [ 48.679695] 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 [ 48.698591] RSP: 002b:00007ffc99b96990 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 48.706292] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f69b7305a3e [ 48.713543] RDX: 0000000000000001 RSI: 00007ffc99b969cc RDI: ffffffffffffffff [ 48.720914] RBP: 000055e67ea3ac88 R08: 00007ffc99b96a90 R09: 0101010101010101 [ 48.728165] R10: 0000000000000000 R11: 0000000000000246 R12: 000055e67f9c2c00 [ 48.735415] R13: 000055e67ea38fb4 R14: 0000000000000028 R15: 000055e67ea3aca0 [ 48.743482] Kernel Offset: disabled [ 48.747108] Rebooting in 86400 seconds..