[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.445519] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.617086] random: sshd: uninitialized urandom read (32 bytes read) [ 18.921985] random: sshd: uninitialized urandom read (32 bytes read) [ 19.596368] random: sshd: uninitialized urandom read (32 bytes read) [ 19.749048] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.43' (ECDSA) to the list of known hosts. [ 25.205534] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 25.298480] IPVS: ftp: loaded support on port[0] = 21 [ 25.327603] ================================================================== [ 25.335001] BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 [ 25.341763] Read of size 8 at addr ffff8801d8324350 by task syz-executor967/4456 [ 25.349275] [ 25.350894] CPU: 0 PID: 4456 Comm: syz-executor967 Not tainted 4.18.0-rc3-next-20180706+ #1 [ 25.359373] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.368839] Call Trace: [ 25.371434] dump_stack+0x1c9/0x2b4 [ 25.375058] ? dump_stack_print_info.cold.2+0x52/0x52 [ 25.380248] ? printk+0xa7/0xcf [ 25.383532] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 25.388316] ? find_first_bit+0xf7/0x100 [ 25.392385] print_address_description+0x6c/0x20b [ 25.397219] ? find_first_bit+0xf7/0x100 [ 25.401285] kasan_report.cold.7+0x242/0x30d [ 25.405685] __asan_report_load8_noabort+0x14/0x20 [ 25.410611] find_first_bit+0xf7/0x100 [ 25.414490] shrink_slab+0x5d0/0xdb0 [ 25.418225] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.423755] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 25.429380] ? shrink_active_list+0x1830/0x1830 [ 25.434048] ? save_stack+0xa9/0xd0 [ 25.437681] ? save_stack+0x43/0xd0 [ 25.441303] ? kernfs_fop_open+0xa7f/0x1020 [ 25.445621] ? do_dentry_open+0xa7d/0x11c0 [ 25.449850] ? trace_hardirqs_on+0x10/0x10 [ 25.454076] shrink_node+0x429/0x16a0 [ 25.457870] ? shrink_node_memcg+0x18f0/0x18f0 [ 25.462454] ? kvm_clock_read+0x25/0x30 [ 25.466955] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 25.471972] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 25.476468] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 25.481485] do_try_to_free_pages+0x3e7/0x1290 [ 25.486069] ? shrink_node+0x16a0/0x16a0 [ 25.490136] ? check_same_owner+0x340/0x340 [ 25.494574] ? trace_hardirqs_on+0x10/0x10 [ 25.498814] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 25.504343] ? _parse_integer+0x13b/0x190 [ 25.508504] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.514049] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 25.519230] ? pointer_string+0x1b0/0x1b0 [ 25.523370] ? try_to_free_pages+0xb80/0xb80 [ 25.527790] ? memparse+0x171/0x1d0 [ 25.531405] ? get_options+0x380/0x380 [ 25.535280] ? kasan_kmalloc+0xc4/0xe0 [ 25.539158] ? __kmalloc+0x14e/0x760 [ 25.542869] ? kernfs_fop_write+0x33d/0x480 [ 25.547461] ? __vfs_write+0x117/0x9f0 [ 25.551349] ? vfs_write+0x1fc/0x560 [ 25.555057] ? ksys_write+0x101/0x260 [ 25.558852] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.564386] ? page_counter_memparse+0xb5/0x1e0 [ 25.569043] ? page_counter_set_low+0x180/0x180 [ 25.573698] ? cgroup_control+0x180/0x180 [ 25.577832] memory_high_write+0x283/0x310 [ 25.582062] ? mem_cgroup_css_released+0x140/0x140 [ 25.586983] ? lock_acquire+0x1e4/0x540 [ 25.590941] ? __might_fault+0x12b/0x1e0 [ 25.595014] cgroup_file_write+0x31f/0x840 [ 25.599246] ? mem_cgroup_css_released+0x140/0x140 [ 25.604162] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 25.609454] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 25.614386] kernfs_fop_write+0x2ba/0x480 [ 25.618537] __vfs_write+0x117/0x9f0 [ 25.622277] ? kernfs_fop_open+0x1020/0x1020 [ 25.626690] ? kernel_read+0x120/0x120 [ 25.630570] ? lock_release+0xa30/0xa30 [ 25.634537] ? check_same_owner+0x340/0x340 [ 25.638868] ? rcu_note_context_switch+0x730/0x730 [ 25.643791] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 25.649321] ? __sb_start_write+0x17f/0x300 [ 25.653637] vfs_write+0x1fc/0x560 [ 25.657177] ksys_write+0x101/0x260 [ 25.660786] ? __ia32_sys_read+0xb0/0xb0 [ 25.664836] __x64_sys_write+0x73/0xb0 [ 25.668712] do_syscall_64+0x1b9/0x820 [ 25.672591] ? syscall_return_slowpath+0x5e0/0x5e0 [ 25.677509] ? syscall_return_slowpath+0x31d/0x5e0 [ 25.682427] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 25.687433] ? prepare_exit_to_usermode+0x291/0x3b0 [ 25.692434] ? perf_trace_sys_enter+0xb10/0xb10 [ 25.697100] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.701930] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.707113] RIP: 0033:0x4419d9 [ 25.710292] Code: e8 ec b5 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 25.729418] RSP: 002b:00007ffe1fe2f928 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 25.737115] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 25.744381] RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000004 [ 25.751648] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 25.759077] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 25.766596] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 25.773860] [ 25.775471] Allocated by task 4455: [ 25.779092] save_stack+0x43/0xd0 [ 25.782529] kasan_kmalloc+0xc4/0xe0 [ 25.786225] __kmalloc_node+0x47/0x70 [ 25.790020] kvmalloc_node+0x65/0xf0 [ 25.793732] mem_cgroup_css_online+0x169/0x3c0 [ 25.798308] online_css+0x10c/0x350 [ 25.802115] cgroup_apply_control_enable+0x777/0xe90 [ 25.807201] cgroup_mkdir+0x88a/0x1170 [ 25.811078] kernfs_iop_mkdir+0x159/0x1e0 [ 25.815212] vfs_mkdir+0x42e/0x6b0 [ 25.818749] do_mkdirat+0x27b/0x310 [ 25.822362] __x64_sys_mkdir+0x5c/0x80 [ 25.826241] do_syscall_64+0x1b9/0x820 [ 25.830111] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.835286] [ 25.836903] Freed by task 2884: [ 25.840167] save_stack+0x43/0xd0 [ 25.843604] __kasan_slab_free+0x11a/0x170 [ 25.847823] kasan_slab_free+0xe/0x10 [ 25.851900] kfree+0xd9/0x260 [ 25.855008] single_release+0x8f/0xb0 [ 25.858800] __fput+0x35d/0x930 [ 25.862062] ____fput+0x15/0x20 [ 25.865331] task_work_run+0x1ec/0x2a0 [ 25.869219] exit_to_usermode_loop+0x313/0x370 [ 25.873784] do_syscall_64+0x6be/0x820 [ 25.877652] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.883080] [ 25.884689] The buggy address belongs to the object at ffff8801d8324340 [ 25.884689] which belongs to the cache kmalloc-32 of size 32 [ 25.897166] The buggy address is located 16 bytes inside of [ 25.897166] 32-byte region [ffff8801d8324340, ffff8801d8324360) [ 25.908861] The buggy address belongs to the page: [ 25.913777] page:ffffea000760c900 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d8324fc1 [ 25.923206] flags: 0x2fffc0000000100(slab) [ 25.927425] raw: 02fffc0000000100 ffffea000760da08 ffffea00075f3348 ffff8801da8001c0 [ 25.935302] raw: ffff8801d8324fc1 ffff8801d8324000 0000000100000032 0000000000000000 [ 25.943165] page dumped because: kasan: bad access detected [ 25.948862] [ 25.950470] Memory state around the buggy address: [ 25.955391] ffff8801d8324200: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 25.962740] ffff8801d8324280: 00 01 fc fc fc fc fc fc fb fb fb fb fc fc fc fc [ 25.970173] >ffff8801d8324300: fb fb fb fb fc fc fc fc 00 00 05 fc fc fc fc fc [ 25.977515] ^ [ 25.983557] ffff8801d8324380: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 25.990902] ffff8801d8324400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 25.998725] ================================================================== [ 26.006161] Kernel panic - not syncing: panic_on_warn set ... [ 26.006161] [ 26.013533] CPU: 0 PID: 4456 Comm: syz-executor967 Tainted: G B 4.18.0-rc3-next-20180706+ #1 [ 26.023394] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.032732] Call Trace: [ 26.035322] dump_stack+0x1c9/0x2b4 [ 26.038951] ? dump_stack_print_info.cold.2+0x52/0x52 [ 26.044130] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.048875] panic+0x238/0x4e7 [ 26.052074] ? add_taint.cold.5+0x16/0x16 [ 26.056313] ? do_raw_spin_unlock+0xa7/0x2f0 [ 26.060714] ? find_first_bit+0xf7/0x100 [ 26.065103] kasan_end_report+0x47/0x4f [ 26.069089] kasan_report.cold.7+0x76/0x30d [ 26.073407] __asan_report_load8_noabort+0x14/0x20 [ 26.078331] find_first_bit+0xf7/0x100 [ 26.082221] shrink_slab+0x5d0/0xdb0 [ 26.085940] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 26.091482] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 26.097110] ? shrink_active_list+0x1830/0x1830 [ 26.101792] ? save_stack+0xa9/0xd0 [ 26.105416] ? save_stack+0x43/0xd0 [ 26.109043] ? kernfs_fop_open+0xa7f/0x1020 [ 26.113368] ? do_dentry_open+0xa7d/0x11c0 [ 26.117602] ? trace_hardirqs_on+0x10/0x10 [ 26.121827] shrink_node+0x429/0x16a0 [ 26.125624] ? shrink_node_memcg+0x18f0/0x18f0 [ 26.130200] ? kvm_clock_read+0x25/0x30 [ 26.134171] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 26.139186] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 26.143668] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 26.148679] do_try_to_free_pages+0x3e7/0x1290 [ 26.153255] ? shrink_node+0x16a0/0x16a0 [ 26.157301] ? check_same_owner+0x340/0x340 [ 26.161607] ? trace_hardirqs_on+0x10/0x10 [ 26.165833] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 26.171368] ? _parse_integer+0x13b/0x190 [ 26.176302] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 26.181842] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 26.187031] ? pointer_string+0x1b0/0x1b0 [ 26.191185] ? try_to_free_pages+0xb80/0xb80 [ 26.195585] ? memparse+0x171/0x1d0 [ 26.199200] ? get_options+0x380/0x380 [ 26.203074] ? kasan_kmalloc+0xc4/0xe0 [ 26.206960] ? __kmalloc+0x14e/0x760 [ 26.210659] ? kernfs_fop_write+0x33d/0x480 [ 26.214966] ? __vfs_write+0x117/0x9f0 [ 26.218841] ? vfs_write+0x1fc/0x560 [ 26.222545] ? ksys_write+0x101/0x260 [ 26.226353] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 26.231880] ? page_counter_memparse+0xb5/0x1e0 [ 26.236538] ? page_counter_set_low+0x180/0x180 [ 26.241192] ? cgroup_control+0x180/0x180 [ 26.245339] memory_high_write+0x283/0x310 [ 26.249561] ? mem_cgroup_css_released+0x140/0x140 [ 26.254497] ? lock_acquire+0x1e4/0x540 [ 26.258457] ? __might_fault+0x12b/0x1e0 [ 26.262517] cgroup_file_write+0x31f/0x840 [ 26.266743] ? mem_cgroup_css_released+0x140/0x140 [ 26.271682] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 26.276619] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 26.281535] kernfs_fop_write+0x2ba/0x480 [ 26.285670] __vfs_write+0x117/0x9f0 [ 26.289382] ? kernfs_fop_open+0x1020/0x1020 [ 26.293778] ? kernel_read+0x120/0x120 [ 26.297665] ? lock_release+0xa30/0xa30 [ 26.301634] ? check_same_owner+0x340/0x340 [ 26.305956] ? rcu_note_context_switch+0x730/0x730 [ 26.310877] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 26.316420] ? __sb_start_write+0x17f/0x300 [ 26.320729] vfs_write+0x1fc/0x560 [ 26.324266] ksys_write+0x101/0x260 [ 26.327890] ? __ia32_sys_read+0xb0/0xb0 [ 26.331949] __x64_sys_write+0x73/0xb0 [ 26.335824] do_syscall_64+0x1b9/0x820 [ 26.339709] ? syscall_return_slowpath+0x5e0/0x5e0 [ 26.344628] ? syscall_return_slowpath+0x31d/0x5e0 [ 26.349543] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 26.354543] ? prepare_exit_to_usermode+0x291/0x3b0 [ 26.359546] ? perf_trace_sys_enter+0xb10/0xb10 [ 26.364205] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.369044] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 26.374244] RIP: 0033:0x4419d9 [ 26.377429] Code: e8 ec b5 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 26.396569] RSP: 002b:00007ffe1fe2f928 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 26.404283] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 26.411549] RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000004 [ 26.418805] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 26.426065] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 26.433328] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 26.441020] Dumping ftrace buffer: [ 26.444545] (ftrace buffer empty) [ 26.448235] Kernel Offset: disabled [ 26.451845] Rebooting in 86400 seconds..