syzkaller login: [ 41.026263] audit: type=1400 audit(1569340880.175:35): avc: denied { map } for pid=7508 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 '10.128.0.254' (ECDSA) to the list of known hosts. executing program [ 47.466434] audit: type=1400 audit(1569340886.615:36): avc: denied { map } for pid=7520 comm="syz-executor846" path="/root/syz-executor846022822" 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 [ 47.493735] FAULT_INJECTION: forcing a failure. [ 47.493735] name failslab, interval 1, probability 0, space 0, times 1 [ 47.505399] CPU: 1 PID: 7520 Comm: syz-executor846 Not tainted 4.19.75 #0 [ 47.512312] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.521644] Call Trace: [ 47.524213] dump_stack+0x172/0x1f0 [ 47.527847] should_fail.cold+0xa/0x1b [ 47.531720] ? fault_create_debugfs_attr+0x1e0/0x1e0 [ 47.536802] ? lock_downgrade+0x810/0x810 [ 47.540949] __should_failslab+0x121/0x190 [ 47.545170] should_failslab+0x9/0x14 [ 47.548953] kmem_cache_alloc_trace+0x2cc/0x760 [ 47.553603] ? kasan_check_read+0x11/0x20 [ 47.557741] cma_alloc_port+0x4d/0x190 [ 47.561611] rdma_bind_addr+0x165a/0x1f80 [ 47.565740] ? ucma_get_ctx+0x82/0x160 [ 47.569613] ? cma_ndev_work_handler+0x1b0/0x1b0 [ 47.574360] ? lock_downgrade+0x810/0x810 [ 47.578499] rdma_resolve_addr+0x438/0x2140 [ 47.582802] ? kasan_check_write+0x14/0x20 [ 47.587019] ? __mutex_unlock_slowpath+0xf8/0x6b0 [ 47.591839] ? lock_downgrade+0x810/0x810 [ 47.595970] ? __radix_tree_lookup+0x219/0x380 [ 47.600540] ? rdma_bind_addr+0x1f80/0x1f80 [ 47.604847] ucma_resolve_ip+0x153/0x210 [ 47.608888] ? ucma_query+0x820/0x820 [ 47.612675] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.618194] ? _copy_from_user+0xdd/0x150 [ 47.622335] ucma_write+0x2d7/0x3c0 [ 47.625942] ? ucma_query+0x820/0x820 [ 47.629751] ? ucma_open+0x290/0x290 [ 47.633451] __vfs_write+0x114/0x810 [ 47.637146] ? ucma_open+0x290/0x290 [ 47.640840] ? kernel_read+0x120/0x120 [ 47.644707] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 47.650226] ? __inode_security_revalidate+0xda/0x120 [ 47.655394] ? avc_policy_seqno+0xd/0x70 [ 47.659435] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 47.664433] ? selinux_file_permission+0x92/0x550 [ 47.669258] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 47.674776] ? security_file_permission+0x89/0x230 [ 47.679686] ? rw_verify_area+0x118/0x360 [ 47.683825] vfs_write+0x20c/0x560 [ 47.687349] ksys_write+0x14f/0x2d0 [ 47.690959] ? __ia32_sys_read+0xb0/0xb0 [ 47.694999] ? do_syscall_64+0x26/0x620 [ 47.698958] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.704300] ? do_syscall_64+0x26/0x620 [ 47.708269] __x64_sys_write+0x73/0xb0 [ 47.712138] do_syscall_64+0xfd/0x620 [ 47.715922] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.721093] RIP: 0033:0x4406d9 [ 47.724268] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 47.743158] RSP: 002b:00007fffa78cda58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 47.750847] RAX: ffffffffffffffda RBX: 00007fffa78cda60 RCX: 00000000004406d9 [ 47.758105] RDX: 0000000000000171 RSI: 0000000020000140 RDI: 0000000000000003 [ 47.765356] RBP: 0000000000000004 R08: 0000000000000001 R09: 00007fffa78c0031 [ 47.772619] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401fc0 [ 47.779869] R13: 0000000000402050 R14: 0000000000000000 R15: 0000000000000000 [ 47.790384] ================================================================== [ 47.797814] BUG: KASAN: use-after-free in wait_consider_task+0x1b51/0x3910 [ 47.804804] Read of size 4 at addr ffff88809a34a82c by task sshd/7518 [ 47.811356] [ 47.812969] CPU: 0 PID: 7518 Comm: sshd Not tainted 4.19.75 #0 [ 47.818916] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.828256] Call Trace: [ 47.830844] dump_stack+0x172/0x1f0 [ 47.834467] ? wait_consider_task+0x1b51/0x3910 [ 47.839120] print_address_description.cold+0x7c/0x20d [ 47.844418] ? wait_consider_task+0x1b51/0x3910 [ 47.849068] kasan_report.cold+0x8c/0x2ba [ 47.853217] __asan_report_load4_noabort+0x14/0x20 [ 47.858164] wait_consider_task+0x1b51/0x3910 [ 47.862647] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 47.867730] ? add_wait_queue+0x112/0x170 [ 47.871864] ? release_task+0x1630/0x1630 [ 47.875991] ? lock_acquire+0x16f/0x3f0 [ 47.879948] ? do_wait+0x3aa/0x9d0 [ 47.883470] ? kasan_check_write+0x14/0x20 [ 47.887686] do_wait+0x439/0x9d0 [ 47.891035] ? wait_consider_task+0x3910/0x3910 [ 47.895683] ? mark_held_locks+0x100/0x100 [ 47.899905] kernel_wait4+0x171/0x290 [ 47.903688] ? __ia32_sys_waitid+0x140/0x140 [ 47.908112] ? task_stopped_code+0x180/0x180 [ 47.912508] __do_sys_wait4+0x147/0x160 [ 47.916461] ? kernel_wait4+0x290/0x290 [ 47.920423] ? kasan_check_read+0x11/0x20 [ 47.924551] ? _copy_to_user+0xc9/0x120 [ 47.928507] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.934024] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 47.939026] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.943762] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.948499] ? do_syscall_64+0x26/0x620 [ 47.952454] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.957798] ? do_syscall_64+0x26/0x620 [ 47.961754] __x64_sys_wait4+0x97/0xf0 [ 47.965621] do_syscall_64+0xfd/0x620 [ 47.969406] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.974584] RIP: 0033:0x7f8bbb1cca3e [ 47.978293] 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 [ 47.997181] RSP: 002b:00007ffcc9ad38f0 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 48.004868] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8bbb1cca3e [ 48.012128] RDX: 0000000000000001 RSI: 00007ffcc9ad392c RDI: ffffffffffffffff [ 48.019378] RBP: 000055a360ae8c88 R08: 00007ffcc9ad39f0 R09: 0101010101010101 [ 48.026626] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a3610b6c00 [ 48.033877] R13: 000055a360ae6fb4 R14: 0000000000000028 R15: 000055a360ae8ca0 [ 48.041149] [ 48.043018] Allocated by task 7518: [ 48.046633] save_stack+0x45/0xd0 [ 48.050067] kasan_kmalloc+0xce/0xf0 [ 48.053772] kasan_slab_alloc+0xf/0x20 [ 48.057638] kmem_cache_alloc_node+0x144/0x710 [ 48.062200] copy_process.part.0+0x1ce0/0x7a30 [ 48.066757] _do_fork+0x257/0xfd0 [ 48.070199] __x64_sys_clone+0xbf/0x150 [ 48.074157] do_syscall_64+0xfd/0x620 [ 48.077937] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.083105] [ 48.084710] Freed by task 0: [ 48.087708] save_stack+0x45/0xd0 [ 48.091148] __kasan_slab_free+0x102/0x150 [ 48.095362] kasan_slab_free+0xe/0x10 [ 48.099147] kmem_cache_free+0x86/0x260 [ 48.103109] free_task+0xdd/0x120 [ 48.106551] __put_task_struct+0x20f/0x4c0 [ 48.110765] finish_task_switch+0x52b/0x780 [ 48.115067] __schedule+0x86e/0x1dc0 [ 48.118763] schedule_idle+0x58/0x80 [ 48.122460] do_idle+0x192/0x560 [ 48.125830] cpu_startup_entry+0xc8/0xe0 [ 48.129882] start_secondary+0x3e8/0x5b0 [ 48.133928] secondary_startup_64+0xa4/0xb0 [ 48.138224] [ 48.139832] The buggy address belongs to the object at ffff88809a34a3c0 [ 48.139832] which belongs to the cache task_struct of size 6080 [ 48.152556] The buggy address is located 1132 bytes inside of [ 48.152556] 6080-byte region [ffff88809a34a3c0, ffff88809a34bb80) [ 48.164581] The buggy address belongs to the page: [ 48.169503] page:ffffea000268d280 count:1 mapcount:0 mapping:ffff88812c26d800 index:0x0 compound_mapcount: 0 [ 48.179454] flags: 0x1fffc0000008100(slab|head) [ 48.184106] raw: 01fffc0000008100 ffffea000247da08 ffffea0002a2f788 ffff88812c26d800 [ 48.191979] raw: 0000000000000000 ffff88809a34a3c0 0000000100000001 0000000000000000 [ 48.199875] page dumped because: kasan: bad access detected [ 48.205565] [ 48.207170] Memory state around the buggy address: [ 48.212079] ffff88809a34a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.219417] ffff88809a34a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.226755] >ffff88809a34a800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.234092] ^ [ 48.238739] ffff88809a34a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.246077] ffff88809a34a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.253435] ================================================================== [ 48.260792] Disabling lock debugging due to kernel taint [ 48.266357] Kernel panic - not syncing: panic_on_warn set ... [ 48.266357] [ 48.273718] CPU: 0 PID: 7518 Comm: sshd Tainted: G B 4.19.75 #0 [ 48.281057] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.290388] Call Trace: [ 48.292956] dump_stack+0x172/0x1f0 [ 48.296564] ? wait_consider_task+0x1b51/0x3910 [ 48.301213] panic+0x263/0x507 [ 48.304385] ? __warn_printk+0xf3/0xf3 [ 48.308252] ? retint_kernel+0x2d/0x2d [ 48.312136] ? trace_hardirqs_on+0x5e/0x220 [ 48.316437] ? wait_consider_task+0x1b51/0x3910 [ 48.321085] kasan_end_report+0x47/0x4f [ 48.325041] kasan_report.cold+0xa9/0x2ba [ 48.329169] __asan_report_load4_noabort+0x14/0x20 [ 48.334079] wait_consider_task+0x1b51/0x3910 [ 48.338560] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 48.343641] ? add_wait_queue+0x112/0x170 [ 48.347781] ? release_task+0x1630/0x1630 [ 48.351907] ? lock_acquire+0x16f/0x3f0 [ 48.355860] ? do_wait+0x3aa/0x9d0 [ 48.359379] ? kasan_check_write+0x14/0x20 [ 48.363591] do_wait+0x439/0x9d0 [ 48.366948] ? wait_consider_task+0x3910/0x3910 [ 48.371602] ? mark_held_locks+0x100/0x100 [ 48.375818] kernel_wait4+0x171/0x290 [ 48.379599] ? __ia32_sys_waitid+0x140/0x140 [ 48.383986] ? task_stopped_code+0x180/0x180 [ 48.388377] __do_sys_wait4+0x147/0x160 [ 48.392332] ? kernel_wait4+0x290/0x290 [ 48.396286] ? kasan_check_read+0x11/0x20 [ 48.400416] ? _copy_to_user+0xc9/0x120 [ 48.404371] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 48.409887] ? __x64_sys_rt_sigprocmask+0x21d/0x2e0 [ 48.414882] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.419616] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 48.424354] ? do_syscall_64+0x26/0x620 [ 48.428310] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.433650] ? do_syscall_64+0x26/0x620 [ 48.437607] __x64_sys_wait4+0x97/0xf0 [ 48.441474] do_syscall_64+0xfd/0x620 [ 48.445253] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.450427] RIP: 0033:0x7f8bbb1cca3e [ 48.454119] 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 [ 48.472999] RSP: 002b:00007ffcc9ad38f0 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 48.480686] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8bbb1cca3e [ 48.487937] RDX: 0000000000000001 RSI: 00007ffcc9ad392c RDI: ffffffffffffffff [ 48.495183] RBP: 000055a360ae8c88 R08: 00007ffcc9ad39f0 R09: 0101010101010101 [ 48.502430] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a3610b6c00 [ 48.509690] R13: 000055a360ae6fb4 R14: 0000000000000028 R15: 000055a360ae8ca0 [ 48.518340] Kernel Offset: disabled [ 48.521962] Rebooting in 86400 seconds..