Warning: Permanently added '10.128.15.221' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 45.148877] audit: type=1400 audit(1569708644.660:36): avc: denied { map } for pid=7556 comm="syz-executor079" path="/root/syz-executor079111337" 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 [ 45.189438] ================================================================== [ 45.196912] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 45.203940] Read of size 4 at addr ffff8880a06c06ec by task sshd/7554 [ 45.210501] [ 45.212119] CPU: 0 PID: 7554 Comm: sshd Not tainted 4.19.75 #0 [ 45.218069] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.227406] Call Trace: [ 45.229988] dump_stack+0x172/0x1f0 [ 45.233602] ? wait_consider_task+0x1b51/0x3910 [ 45.238255] print_address_description.cold+0x7c/0x20d [ 45.243558] ? wait_consider_task+0x1b51/0x3910 [ 45.249093] kasan_report.cold+0x8c/0x2ba [ 45.253232] __asan_report_load4_noabort+0x14/0x20 [ 45.258149] wait_consider_task+0x1b51/0x3910 [ 45.262633] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 45.267727] ? add_wait_queue+0x112/0x170 [ 45.271861] ? release_task+0x1630/0x1630 [ 45.276118] ? lock_acquire+0x16f/0x3f0 [ 45.280090] ? do_wait+0x3aa/0x9d0 [ 45.283625] ? kasan_check_write+0x14/0x20 [ 45.287852] do_wait+0x439/0x9d0 [ 45.291254] ? wait_consider_task+0x3910/0x3910 [ 45.295942] ? mark_held_locks+0x100/0x100 [ 45.300169] kernel_wait4+0x171/0x290 [ 45.303958] ? __ia32_sys_waitid+0x140/0x140 [ 45.308363] ? task_stopped_code+0x180/0x180 [ 45.312775] __do_sys_wait4+0x147/0x160 [ 45.316737] ? kernel_wait4+0x290/0x290 [ 45.320718] ? kasan_check_read+0x11/0x20 [ 45.324907] ? _copy_to_user+0xc9/0x120 [ 45.328876] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 45.334409] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 45.339414] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.344156] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.348898] ? do_syscall_64+0x26/0x620 [ 45.352854] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.358200] ? do_syscall_64+0x26/0x620 [ 45.362159] __x64_sys_wait4+0x97/0xf0 [ 45.366035] do_syscall_64+0xfd/0x620 [ 45.369835] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.375529] RIP: 0033:0x7f6812700a3e [ 45.379227] 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 [ 45.398372] RSP: 002b:00007ffed060ad70 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 45.406065] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6812700a3e [ 45.413317] RDX: 0000000000000001 RSI: 00007ffed060adac RDI: ffffffffffffffff [ 45.420576] RBP: 00005571d7a3fc88 R08: 00007ffed060ae70 R09: 0101010101010101 [ 45.427827] R10: 0000000000000000 R11: 0000000000000246 R12: 00005571d7d93db0 [ 45.435077] R13: 00005571d7a3dfb4 R14: 0000000000000028 R15: 00005571d7a3fca0 [ 45.442338] [ 45.443947] Allocated by task 7554: [ 45.447562] save_stack+0x45/0xd0 [ 45.450997] kasan_kmalloc+0xce/0xf0 [ 45.454692] kasan_slab_alloc+0xf/0x20 [ 45.458575] kmem_cache_alloc_node+0x144/0x710 [ 45.463136] copy_process.part.0+0x1ce0/0x7a30 [ 45.467696] _do_fork+0x257/0xfd0 [ 45.471131] __x64_sys_clone+0xbf/0x150 [ 45.475086] do_syscall_64+0xfd/0x620 [ 45.478874] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.484038] [ 45.485646] Freed by task 0: [ 45.488647] save_stack+0x45/0xd0 [ 45.492080] __kasan_slab_free+0x102/0x150 [ 45.496294] kasan_slab_free+0xe/0x10 [ 45.500076] kmem_cache_free+0x86/0x260 [ 45.504029] free_task+0xdd/0x120 [ 45.507476] __put_task_struct+0x20f/0x4c0 [ 45.511692] finish_task_switch+0x52b/0x780 [ 45.515994] __schedule+0x86e/0x1dc0 [ 45.519690] schedule_idle+0x58/0x80 [ 45.523411] do_idle+0x192/0x560 [ 45.526767] cpu_startup_entry+0xc8/0xe0 [ 45.530815] start_secondary+0x3e8/0x5b0 [ 45.534870] secondary_startup_64+0xa4/0xb0 [ 45.539169] [ 45.540791] The buggy address belongs to the object at ffff8880a06c0280 [ 45.540791] which belongs to the cache task_struct of size 6080 [ 45.553530] The buggy address is located 1132 bytes inside of [ 45.553530] 6080-byte region [ffff8880a06c0280, ffff8880a06c1a40) [ 45.565556] The buggy address belongs to the page: [ 45.570469] page:ffffea000281b000 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 45.580541] flags: 0x1fffc0000008100(slab|head) [ 45.585199] raw: 01fffc0000008100 ffffea00020a3408 ffffea0002489e08 ffff88812c26d800 [ 45.593239] raw: 0000000000000000 ffff8880a06c0280 0000000100000001 0000000000000000 [ 45.601102] page dumped because: kasan: bad access detected [ 45.606792] [ 45.608410] Memory state around the buggy address: [ 45.613338] ffff8880a06c0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.620699] ffff8880a06c0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.628322] >ffff8880a06c0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.635670] ^ [ 45.642407] ffff8880a06c0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.649750] ffff8880a06c0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.657100] ================================================================== [ 45.664447] Disabling lock debugging due to kernel taint [ 45.670033] Kernel panic - not syncing: panic_on_warn set ... [ 45.670033] [ 45.677416] CPU: 0 PID: 7554 Comm: sshd Tainted: G B 4.19.75 #0 [ 45.684799] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.694138] Call Trace: [ 45.696713] dump_stack+0x172/0x1f0 [ 45.700342] ? wait_consider_task+0x1b51/0x3910 [ 45.705165] panic+0x263/0x507 [ 45.708341] ? __warn_printk+0xf3/0xf3 [ 45.712210] ? retint_kernel+0x2d/0x2d [ 45.716100] ? trace_hardirqs_on+0x5e/0x220 [ 45.720446] ? wait_consider_task+0x1b51/0x3910 [ 45.725105] kasan_end_report+0x47/0x4f [ 45.729068] kasan_report.cold+0xa9/0x2ba [ 45.733198] __asan_report_load4_noabort+0x14/0x20 [ 45.738112] wait_consider_task+0x1b51/0x3910 [ 45.742594] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 45.747678] ? add_wait_queue+0x112/0x170 [ 45.751810] ? release_task+0x1630/0x1630 [ 45.755938] ? lock_acquire+0x16f/0x3f0 [ 45.759894] ? do_wait+0x3aa/0x9d0 [ 45.763430] ? kasan_check_write+0x14/0x20 [ 45.767648] do_wait+0x439/0x9d0 [ 45.770997] ? wait_consider_task+0x3910/0x3910 [ 45.775653] ? mark_held_locks+0x100/0x100 [ 45.779890] kernel_wait4+0x171/0x290 [ 45.783691] ? __ia32_sys_waitid+0x140/0x140 [ 45.788129] ? task_stopped_code+0x180/0x180 [ 45.792525] __do_sys_wait4+0x147/0x160 [ 45.796482] ? kernel_wait4+0x290/0x290 [ 45.800440] ? kasan_check_read+0x11/0x20 [ 45.804567] ? _copy_to_user+0xc9/0x120 [ 45.808525] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 45.814081] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 45.819079] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.823817] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.828555] ? do_syscall_64+0x26/0x620 [ 45.832514] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.837860] ? do_syscall_64+0x26/0x620 [ 45.841816] __x64_sys_wait4+0x97/0xf0 [ 45.845704] do_syscall_64+0xfd/0x620 [ 45.849509] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.854690] RIP: 0033:0x7f6812700a3e [ 45.858548] 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 [ 45.877538] RSP: 002b:00007ffed060ad70 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 45.885238] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6812700a3e [ 45.892506] RDX: 0000000000000001 RSI: 00007ffed060adac RDI: ffffffffffffffff [ 45.899766] RBP: 00005571d7a3fc88 R08: 00007ffed060ae70 R09: 0101010101010101 [ 45.907033] R10: 0000000000000000 R11: 0000000000000246 R12: 00005571d7d93db0 [ 45.914299] R13: 00005571d7a3dfb4 R14: 0000000000000028 R15: 00005571d7a3fca0 [ 45.922796] Kernel Offset: disabled [ 45.926431] Rebooting in 86400 seconds..