[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.461917] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.916864] random: sshd: uninitialized urandom read (32 bytes read) [ 24.319240] random: sshd: uninitialized urandom read (32 bytes read) [ 25.088264] random: sshd: uninitialized urandom read (32 bytes read) [ 25.247787] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.23' (ECDSA) to the list of known hosts. [ 30.702290] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 33.240338] ================================================================== [ 33.247840] BUG: KASAN: use-after-free in __list_del_entry_valid+0xe7/0xf3 [ 33.254837] Read of size 8 at addr ffff8801d4356de0 by task syz-executor759/7373 [ 33.262345] [ 33.263960] CPU: 1 PID: 7373 Comm: syz-executor759 Not tainted 4.17.0-rc6+ #61 [ 33.271297] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.280638] Call Trace: [ 33.283215] dump_stack+0x1b9/0x294 [ 33.286827] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.292001] ? printk+0x9e/0xba [ 33.295277] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 33.300026] ? kasan_check_write+0x14/0x20 [ 33.304248] print_address_description+0x6c/0x20b [ 33.309076] ? __list_del_entry_valid+0xe7/0xf3 [ 33.313728] kasan_report.cold.7+0x242/0x2fe [ 33.318120] __asan_report_load8_noabort+0x14/0x20 [ 33.323039] __list_del_entry_valid+0xe7/0xf3 [ 33.327519] cma_cancel_operation+0x457/0xe90 [ 33.331996] ? finish_task_switch+0x28b/0x840 [ 33.336478] ? find_held_lock+0x36/0x1c0 [ 33.340532] ? rdma_destroy_id+0xe50/0xe50 [ 33.344749] ? lock_downgrade+0x8e0/0x8e0 [ 33.348880] ? kasan_check_read+0x11/0x20 [ 33.353011] ? do_raw_spin_unlock+0x9e/0x2e0 [ 33.357411] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.361997] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 33.367091] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.372091] rdma_destroy_id+0xff/0xe50 [ 33.376051] ? cma_release_dev+0x370/0x370 [ 33.380273] ? radix_tree_delete_item+0x14d/0x2d0 [ 33.385107] ? rcu_is_watching+0x85/0x140 [ 33.389255] ? radix_tree_lookup+0x30/0x30 [ 33.393486] ucma_close+0x100/0x300 [ 33.397097] ? ucma_free_ctx+0xdf0/0xdf0 [ 33.401148] __fput+0x34d/0x890 [ 33.404417] ? fput+0x1a0/0x1a0 [ 33.407697] ? check_same_owner+0x320/0x320 [ 33.412013] ? _raw_spin_unlock_irq+0x27/0x70 [ 33.416503] ____fput+0x15/0x20 [ 33.419775] task_work_run+0x1e4/0x290 [ 33.423643] ? task_work_cancel+0x240/0x240 [ 33.427974] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 33.433494] ? switch_task_namespaces+0xa2/0xd0 [ 33.438147] do_exit+0x1aee/0x2730 [ 33.441672] ? find_held_lock+0x36/0x1c0 [ 33.445717] ? mm_update_next_owner+0x980/0x980 [ 33.450365] ? print_usage_bug+0xc0/0xc0 [ 33.454407] ? lock_downgrade+0x8e0/0x8e0 [ 33.458538] ? __lock_acquire+0x7f5/0x5140 [ 33.462763] ? graph_lock+0x170/0x170 [ 33.466547] ? __lock_acquire+0x7f5/0x5140 [ 33.470761] ? debug_check_no_locks_freed+0x310/0x310 [ 33.475940] ? graph_lock+0x170/0x170 [ 33.479723] ? __lock_is_held+0xb5/0x140 [ 33.483769] ? debug_check_no_locks_freed+0x310/0x310 [ 33.488939] ? __lock_is_held+0xb5/0x140 [ 33.493002] ? __account_cfs_rq_runtime+0x600/0x600 [ 33.498015] ? set_next_entity+0x2ae/0xaf0 [ 33.502238] ? debug_check_no_locks_freed+0x310/0x310 [ 33.507422] ? update_load_avg+0x2570/0x2570 [ 33.511841] ? graph_lock+0x170/0x170 [ 33.515628] ? graph_lock+0x170/0x170 [ 33.519413] ? graph_lock+0x170/0x170 [ 33.523197] ? find_held_lock+0x36/0x1c0 [ 33.527243] ? memset+0x31/0x40 [ 33.530504] ? find_held_lock+0x36/0x1c0 [ 33.534566] ? lock_downgrade+0x8e0/0x8e0 [ 33.538704] do_group_exit+0x16f/0x430 [ 33.542573] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.547135] ? __ia32_sys_exit+0x50/0x50 [ 33.551177] ? _raw_spin_unlock_irq+0x27/0x70 [ 33.555652] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.560661] get_signal+0x886/0x1960 [ 33.564369] ? ptrace_notify+0x130/0x130 [ 33.568426] ? __schedule+0x809/0x1e30 [ 33.572312] ? _copy_from_user+0xdf/0x150 [ 33.576454] ? __sched_text_start+0x8/0x8 [ 33.580586] ? ucma_close_id+0x60/0x60 [ 33.584472] do_signal+0x98/0x2040 [ 33.587997] ? __vfs_write+0x113/0x960 [ 33.591886] ? __fget_light+0x2ef/0x430 [ 33.595846] ? ucma_close_id+0x60/0x60 [ 33.599714] ? kernel_read+0x120/0x120 [ 33.603586] ? setup_sigcontext+0x7d0/0x7d0 [ 33.607892] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.613408] ? fsnotify+0x415/0xfc0 [ 33.617030] ? schedule+0xef/0x430 [ 33.620563] ? fsnotify+0xfc0/0xfc0 [ 33.624182] ? __schedule+0x1e30/0x1e30 [ 33.628146] ? exit_to_usermode_loop+0x87/0x310 [ 33.632801] exit_to_usermode_loop+0x28a/0x310 [ 33.637379] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 33.642202] ? do_syscall_64+0x92/0x800 [ 33.646162] do_syscall_64+0x6ac/0x800 [ 33.650046] ? finish_task_switch+0x1ca/0x840 [ 33.654526] ? syscall_return_slowpath+0x5c0/0x5c0 [ 33.659437] ? syscall_return_slowpath+0x30f/0x5c0 [ 33.664350] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 33.669693] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.674519] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.679687] RIP: 0033:0x445dc9 [ 33.682855] RSP: 002b:00007fb645d7fda8 EFLAGS: 00000202 ORIG_RAX: 00000000000000ca [ 33.690543] RAX: 0000000000000001 RBX: 00000000006dbc3c RCX: 0000000000445dc9 [ 33.697790] RDX: 0000000000445dc9 RSI: 0000000000000001 RDI: 00000000006dbc3c [ 33.705049] RBP: 00000000006dbc38 R08: 0000000000000000 R09: 0000000000000000 [ 33.712316] R10: 0000000000000000 R11: 0000000000000202 R12: 006d635f616d6472 [ 33.719566] R13: 2f646e6162696e69 R14: 666e692f7665642f R15: 0000000000000005 [ 33.726822] [ 33.728429] Allocated by task 7370: [ 33.732051] save_stack+0x43/0xd0 [ 33.735485] kasan_kmalloc+0xc4/0xe0 [ 33.739180] kmem_cache_alloc_trace+0x152/0x780 [ 33.743833] __rdma_create_id+0xd7/0x710 [ 33.747874] ucma_create_id+0x385/0x9b0 [ 33.751826] ucma_write+0x328/0x410 [ 33.755433] __vfs_write+0x10b/0x960 [ 33.759122] vfs_write+0x1f8/0x560 [ 33.762644] ksys_write+0xf9/0x250 [ 33.766165] __x64_sys_write+0x73/0xb0 [ 33.770041] do_syscall_64+0x1b1/0x800 [ 33.773910] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.779085] [ 33.780690] Freed by task 7373: [ 33.783954] save_stack+0x43/0xd0 [ 33.787396] __kasan_slab_free+0x11a/0x170 [ 33.791609] kasan_slab_free+0xe/0x10 [ 33.795399] kfree+0xd9/0x260 [ 33.798485] rdma_destroy_id+0x8c5/0xe50 [ 33.802529] ucma_close+0x100/0x300 [ 33.806139] __fput+0x34d/0x890 [ 33.809410] ____fput+0x15/0x20 [ 33.812673] task_work_run+0x1e4/0x290 [ 33.816541] do_exit+0x1aee/0x2730 [ 33.820072] do_group_exit+0x16f/0x430 [ 33.824038] get_signal+0x886/0x1960 [ 33.827739] do_signal+0x98/0x2040 [ 33.831273] exit_to_usermode_loop+0x28a/0x310 [ 33.835836] do_syscall_64+0x6ac/0x800 [ 33.839713] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.844875] [ 33.846485] The buggy address belongs to the object at ffff8801d4356c00 [ 33.846485] which belongs to the cache kmalloc-2048 of size 2048 [ 33.859297] The buggy address is located 480 bytes inside of [ 33.859297] 2048-byte region [ffff8801d4356c00, ffff8801d4357400) [ 33.871234] The buggy address belongs to the page: [ 33.876144] page:ffffea000750d580 count:1 mapcount:0 mapping:ffff8801d4356380 index:0x0 compound_mapcount: 0 [ 33.886100] flags: 0x2fffc0000008100(slab|head) [ 33.890751] raw: 02fffc0000008100 ffff8801d4356380 0000000000000000 0000000100000003 [ 33.898621] raw: ffffea00075c8a20 ffffea000750d8a0 ffff8801da800c40 0000000000000000 [ 33.906489] page dumped because: kasan: bad access detected [ 33.912174] [ 33.913780] Memory state around the buggy address: [ 33.918690] ffff8801d4356c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.926035] ffff8801d4356d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.933384] >ffff8801d4356d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.940723] ^ [ 33.947204] ffff8801d4356e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.954642] ffff8801d4356e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.961976] ================================================================== [ 33.969311] Disabling lock debugging due to kernel taint [ 33.974890] Kernel panic - not syncing: panic_on_warn set ... [ 33.974890] [ 33.982264] CPU: 1 PID: 7373 Comm: syz-executor759 Tainted: G B 4.17.0-rc6+ #61 [ 33.991004] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.000345] Call Trace: [ 34.002919] dump_stack+0x1b9/0x294 [ 34.006529] ? dump_stack_print_info.cold.2+0x52/0x52 [ 34.011711] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 34.016470] ? __list_del_entry_valid+0xe0/0xf3 [ 34.021120] panic+0x22f/0x4de [ 34.024290] ? add_taint.cold.5+0x16/0x16 [ 34.028420] ? do_raw_spin_unlock+0x9e/0x2e0 [ 34.032808] ? do_raw_spin_unlock+0x9e/0x2e0 [ 34.037194] ? __list_del_entry_valid+0xe7/0xf3 [ 34.041850] kasan_end_report+0x47/0x4f [ 34.045817] kasan_report.cold.7+0x76/0x2fe [ 34.050131] __asan_report_load8_noabort+0x14/0x20 [ 34.055041] __list_del_entry_valid+0xe7/0xf3 [ 34.059530] cma_cancel_operation+0x457/0xe90 [ 34.064005] ? finish_task_switch+0x28b/0x840 [ 34.068485] ? find_held_lock+0x36/0x1c0 [ 34.072525] ? rdma_destroy_id+0xe50/0xe50 [ 34.076739] ? lock_downgrade+0x8e0/0x8e0 [ 34.080867] ? kasan_check_read+0x11/0x20 [ 34.084997] ? do_raw_spin_unlock+0x9e/0x2e0 [ 34.089405] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 34.093971] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 34.099055] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.104057] rdma_destroy_id+0xff/0xe50 [ 34.108019] ? cma_release_dev+0x370/0x370 [ 34.112246] ? radix_tree_delete_item+0x14d/0x2d0 [ 34.117093] ? rcu_is_watching+0x85/0x140 [ 34.121225] ? radix_tree_lookup+0x30/0x30 [ 34.125448] ucma_close+0x100/0x300 [ 34.129059] ? ucma_free_ctx+0xdf0/0xdf0 [ 34.133104] __fput+0x34d/0x890 [ 34.136381] ? fput+0x1a0/0x1a0 [ 34.139656] ? check_same_owner+0x320/0x320 [ 34.143972] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.148455] ____fput+0x15/0x20 [ 34.151717] task_work_run+0x1e4/0x290 [ 34.155594] ? task_work_cancel+0x240/0x240 [ 34.159921] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 34.165438] ? switch_task_namespaces+0xa2/0xd0 [ 34.170086] do_exit+0x1aee/0x2730 [ 34.173622] ? find_held_lock+0x36/0x1c0 [ 34.177663] ? mm_update_next_owner+0x980/0x980 [ 34.182314] ? print_usage_bug+0xc0/0xc0 [ 34.186371] ? lock_downgrade+0x8e0/0x8e0 [ 34.190499] ? __lock_acquire+0x7f5/0x5140 [ 34.194711] ? graph_lock+0x170/0x170 [ 34.198492] ? __lock_acquire+0x7f5/0x5140 [ 34.202724] ? debug_check_no_locks_freed+0x310/0x310 [ 34.207892] ? graph_lock+0x170/0x170 [ 34.211670] ? __lock_is_held+0xb5/0x140 [ 34.215720] ? debug_check_no_locks_freed+0x310/0x310 [ 34.220896] ? __lock_is_held+0xb5/0x140 [ 34.224946] ? __account_cfs_rq_runtime+0x600/0x600 [ 34.229953] ? set_next_entity+0x2ae/0xaf0 [ 34.234164] ? debug_check_no_locks_freed+0x310/0x310 [ 34.239332] ? update_load_avg+0x2570/0x2570 [ 34.243729] ? graph_lock+0x170/0x170 [ 34.247508] ? graph_lock+0x170/0x170 [ 34.251286] ? graph_lock+0x170/0x170 [ 34.255066] ? find_held_lock+0x36/0x1c0 [ 34.259112] ? memset+0x31/0x40 [ 34.262369] ? find_held_lock+0x36/0x1c0 [ 34.266409] ? lock_downgrade+0x8e0/0x8e0 [ 34.270991] do_group_exit+0x16f/0x430 [ 34.274860] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 34.279419] ? __ia32_sys_exit+0x50/0x50 [ 34.283458] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.287932] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.292930] get_signal+0x886/0x1960 [ 34.296629] ? ptrace_notify+0x130/0x130 [ 34.300673] ? __schedule+0x809/0x1e30 [ 34.304540] ? _copy_from_user+0xdf/0x150 [ 34.308670] ? __sched_text_start+0x8/0x8 [ 34.312799] ? ucma_close_id+0x60/0x60 [ 34.316672] do_signal+0x98/0x2040 [ 34.320190] ? __vfs_write+0x113/0x960 [ 34.324060] ? __fget_light+0x2ef/0x430 [ 34.328031] ? ucma_close_id+0x60/0x60 [ 34.331906] ? kernel_read+0x120/0x120 [ 34.335772] ? setup_sigcontext+0x7d0/0x7d0 [ 34.340072] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.345591] ? fsnotify+0x415/0xfc0 [ 34.349204] ? schedule+0xef/0x430 [ 34.352720] ? fsnotify+0xfc0/0xfc0 [ 34.356326] ? __schedule+0x1e30/0x1e30 [ 34.360286] ? exit_to_usermode_loop+0x87/0x310 [ 34.364936] exit_to_usermode_loop+0x28a/0x310 [ 34.369499] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 34.374321] ? do_syscall_64+0x92/0x800 [ 34.378273] do_syscall_64+0x6ac/0x800 [ 34.382145] ? finish_task_switch+0x1ca/0x840 [ 34.386620] ? syscall_return_slowpath+0x5c0/0x5c0 [ 34.391529] ? syscall_return_slowpath+0x30f/0x5c0 [ 34.396439] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 34.401800] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.407059] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.412225] RIP: 0033:0x445dc9 [ 34.415413] RSP: 002b:00007fb645d7fda8 EFLAGS: 00000202 ORIG_RAX: 00000000000000ca [ 34.423112] RAX: 0000000000000001 RBX: 00000000006dbc3c RCX: 0000000000445dc9 [ 34.430372] RDX: 0000000000445dc9 RSI: 0000000000000001 RDI: 00000000006dbc3c [ 34.437626] RBP: 00000000006dbc38 R08: 0000000000000000 R09: 0000000000000000 [ 34.444875] R10: 0000000000000000 R11: 0000000000000202 R12: 006d635f616d6472 [ 34.452123] R13: 2f646e6162696e69 R14: 666e692f7665642f R15: 0000000000000005 [ 34.459864] Dumping ftrace buffer: [ 34.463397] (ftrace buffer empty) [ 34.467083] Kernel Offset: disabled [ 34.470696] Rebooting in 86400 seconds..