[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 17.130544] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.424717] random: sshd: uninitialized urandom read (32 bytes read) [ 19.785607] random: sshd: uninitialized urandom read (32 bytes read) [ 20.507241] random: sshd: uninitialized urandom read (32 bytes read) [ 29.827955] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.17' (ECDSA) to the list of known hosts. [ 35.266603] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 35.365216] IPVS: ftp: loaded support on port[0] = 21 [ 35.397109] ================================================================== [ 35.404669] BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 [ 35.411599] Read of size 8 at addr ffff8801d8a2eb10 by task syz-executor627/4470 [ 35.419410] [ 35.421050] CPU: 1 PID: 4470 Comm: syz-executor627 Not tainted 4.18.0-rc3-next-20180706+ #1 [ 35.429650] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.439008] Call Trace: [ 35.441640] dump_stack+0x1c9/0x2b4 [ 35.445566] ? dump_stack_print_info.cold.2+0x52/0x52 [ 35.450770] ? printk+0xa7/0xcf [ 35.454062] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 35.458941] ? find_first_bit+0xf7/0x100 [ 35.463034] print_address_description+0x6c/0x20b [ 35.467983] ? find_first_bit+0xf7/0x100 [ 35.472060] kasan_report.cold.7+0x242/0x30d [ 35.476867] __asan_report_load8_noabort+0x14/0x20 [ 35.481831] find_first_bit+0xf7/0x100 [ 35.485935] shrink_slab+0x5d0/0xdb0 [ 35.489669] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 35.495242] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 35.500889] ? shrink_active_list+0x1830/0x1830 [ 35.505590] ? save_stack+0xa9/0xd0 [ 35.509233] ? save_stack+0x43/0xd0 [ 35.512899] ? kernfs_fop_open+0xa7f/0x1020 [ 35.517247] ? do_dentry_open+0xa7d/0x11c0 [ 35.521496] ? trace_hardirqs_on+0x10/0x10 [ 35.525746] shrink_node+0x429/0x16a0 [ 35.529920] ? shrink_node_memcg+0x18f0/0x18f0 [ 35.534514] ? kvm_clock_read+0x25/0x30 [ 35.538503] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 35.543543] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 35.548060] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 35.553125] do_try_to_free_pages+0x3e7/0x1290 [ 35.557727] ? shrink_node+0x16a0/0x16a0 [ 35.561799] ? check_same_owner+0x340/0x340 [ 35.566138] ? trace_hardirqs_on+0x10/0x10 [ 35.570426] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 35.575977] ? _parse_integer+0x13b/0x190 [ 35.580154] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 35.585707] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 35.591081] ? pointer_string+0x1b0/0x1b0 [ 35.595241] ? try_to_free_pages+0xb80/0xb80 [ 35.600397] ? memparse+0x171/0x1d0 [ 35.604390] ? get_options+0x380/0x380 [ 35.608314] ? kasan_kmalloc+0xc4/0xe0 [ 35.613255] ? __kmalloc+0x14e/0x760 [ 35.617067] ? kernfs_fop_write+0x33d/0x480 [ 35.621399] ? __vfs_write+0x117/0x9f0 [ 35.625318] ? vfs_write+0x1fc/0x560 [ 35.629061] ? ksys_write+0x101/0x260 [ 35.632894] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 35.638446] ? page_counter_memparse+0xb5/0x1e0 [ 35.643136] ? page_counter_set_low+0x180/0x180 [ 35.647833] ? cgroup_control+0x180/0x180 [ 35.651995] memory_high_write+0x283/0x310 [ 35.656512] ? mem_cgroup_css_released+0x140/0x140 [ 35.661463] ? lock_acquire+0x1e4/0x540 [ 35.665549] ? __might_fault+0x12b/0x1e0 [ 35.669831] cgroup_file_write+0x31f/0x840 [ 35.674182] ? mem_cgroup_css_released+0x140/0x140 [ 35.679208] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 35.684258] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 35.689289] kernfs_fop_write+0x2ba/0x480 [ 35.693566] __vfs_write+0x117/0x9f0 [ 35.697293] ? kernfs_fop_open+0x1020/0x1020 [ 35.702710] ? kernel_read+0x120/0x120 [ 35.706610] ? lock_release+0xa30/0xa30 [ 35.710688] ? check_same_owner+0x340/0x340 [ 35.715221] ? rcu_note_context_switch+0x730/0x730 [ 35.720352] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 35.725915] ? __sb_start_write+0x17f/0x300 [ 35.730572] vfs_write+0x1fc/0x560 [ 35.734114] ksys_write+0x101/0x260 [ 35.738726] ? __ia32_sys_read+0xb0/0xb0 [ 35.744713] __x64_sys_write+0x73/0xb0 [ 35.748626] do_syscall_64+0x1b9/0x820 [ 35.752631] ? syscall_return_slowpath+0x5e0/0x5e0 [ 35.757577] ? syscall_return_slowpath+0x31d/0x5e0 [ 35.762692] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 35.767725] ? prepare_exit_to_usermode+0x291/0x3b0 [ 35.772866] ? perf_trace_sys_enter+0xb10/0xb10 [ 35.777532] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.782517] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.787992] RIP: 0033:0x4419d9 [ 35.791169] 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 [ 35.810908] RSP: 002b:00007ffd86fe0fd8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 35.818720] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 35.827138] RDX: 0000000000000104 RSI: 0000000020000080 RDI: 0000000000000004 [ 35.834513] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 35.842585] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 35.850051] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 35.857791] [ 35.859625] Allocated by task 4469: [ 35.863283] save_stack+0x43/0xd0 [ 35.867124] kasan_kmalloc+0xc4/0xe0 [ 35.870861] __kmalloc_node+0x47/0x70 [ 35.875122] kvmalloc_node+0x65/0xf0 [ 35.879121] mem_cgroup_css_online+0x169/0x3c0 [ 35.883733] online_css+0x10c/0x350 [ 35.887476] cgroup_apply_control_enable+0x777/0xe90 [ 35.893123] cgroup_mkdir+0x88a/0x1170 [ 35.897585] kernfs_iop_mkdir+0x159/0x1e0 [ 35.901723] vfs_mkdir+0x42e/0x6b0 [ 35.905274] do_mkdirat+0x27b/0x310 [ 35.909018] __x64_sys_mkdir+0x5c/0x80 [ 35.912930] do_syscall_64+0x1b9/0x820 [ 35.916824] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.922001] [ 35.923648] Freed by task 2896: [ 35.927642] save_stack+0x43/0xd0 [ 35.931198] __kasan_slab_free+0x11a/0x170 [ 35.935474] kasan_slab_free+0xe/0x10 [ 35.939541] kfree+0xd9/0x260 [ 35.942665] single_release+0x8f/0xb0 [ 35.946664] __fput+0x35d/0x930 [ 35.950051] ____fput+0x15/0x20 [ 35.953369] task_work_run+0x1ec/0x2a0 [ 35.957281] exit_to_usermode_loop+0x313/0x370 [ 35.961871] do_syscall_64+0x6be/0x820 [ 35.965974] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.971244] [ 35.972870] The buggy address belongs to the object at ffff8801d8a2eb00 [ 35.972870] which belongs to the cache kmalloc-32 of size 32 [ 35.985712] The buggy address is located 16 bytes inside of [ 35.985712] 32-byte region [ffff8801d8a2eb00, ffff8801d8a2eb20) [ 35.997506] The buggy address belongs to the page: [ 36.002436] page:ffffea0007628b80 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d8a2efc1 [ 36.013006] flags: 0x2fffc0000000100(slab) [ 36.017495] raw: 02fffc0000000100 ffffea000762a7c8 ffffea00076165c8 ffff8801da8001c0 [ 36.025648] raw: ffff8801d8a2efc1 ffff8801d8a2e000 000000010000002e 0000000000000000 [ 36.034392] page dumped because: kasan: bad access detected [ 36.040204] [ 36.041824] Memory state around the buggy address: [ 36.046774] ffff8801d8a2ea00: fb fb fb fb fc fc fc fc 00 01 fc fc fc fc fc fc [ 36.054136] ffff8801d8a2ea80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 36.061522] >ffff8801d8a2eb00: 00 00 05 fc fc fc fc fc fb fb fb fb fc fc fc fc [ 36.068873] ^ [ 36.072773] ffff8801d8a2eb80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 36.080139] ffff8801d8a2ec00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 36.087493] ================================================================== [ 36.095569] Kernel panic - not syncing: panic_on_warn set ... [ 36.095569] [ 36.102942] CPU: 1 PID: 4470 Comm: syz-executor627 Tainted: G B 4.18.0-rc3-next-20180706+ #1 [ 36.113144] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.122504] Call Trace: [ 36.125099] dump_stack+0x1c9/0x2b4 [ 36.128995] ? dump_stack_print_info.cold.2+0x52/0x52 [ 36.134308] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 36.139856] panic+0x238/0x4e7 [ 36.143072] ? add_taint.cold.5+0x16/0x16 [ 36.147234] ? do_raw_spin_unlock+0xa7/0x2f0 [ 36.151650] ? find_first_bit+0xf7/0x100 [ 36.155699] kasan_end_report+0x47/0x4f [ 36.159658] kasan_report.cold.7+0x76/0x30d [ 36.164409] __asan_report_load8_noabort+0x14/0x20 [ 36.169416] find_first_bit+0xf7/0x100 [ 36.173306] shrink_slab+0x5d0/0xdb0 [ 36.177013] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 36.182811] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 36.189299] ? shrink_active_list+0x1830/0x1830 [ 36.193973] ? save_stack+0xa9/0xd0 [ 36.198219] ? save_stack+0x43/0xd0 [ 36.201935] ? kernfs_fop_open+0xa7f/0x1020 [ 36.206434] ? do_dentry_open+0xa7d/0x11c0 [ 36.210744] ? trace_hardirqs_on+0x10/0x10 [ 36.215009] shrink_node+0x429/0x16a0 [ 36.218896] ? shrink_node_memcg+0x18f0/0x18f0 [ 36.223581] ? kvm_clock_read+0x25/0x30 [ 36.227557] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 36.232572] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 36.237077] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 36.242106] do_try_to_free_pages+0x3e7/0x1290 [ 36.246710] ? shrink_node+0x16a0/0x16a0 [ 36.250795] ? check_same_owner+0x340/0x340 [ 36.255983] ? trace_hardirqs_on+0x10/0x10 [ 36.260238] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 36.265775] ? _parse_integer+0x13b/0x190 [ 36.269929] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 36.275985] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 36.281177] ? pointer_string+0x1b0/0x1b0 [ 36.285467] ? try_to_free_pages+0xb80/0xb80 [ 36.289962] ? memparse+0x171/0x1d0 [ 36.293850] ? get_options+0x380/0x380 [ 36.297944] ? kasan_kmalloc+0xc4/0xe0 [ 36.302714] ? __kmalloc+0x14e/0x760 [ 36.306427] ? kernfs_fop_write+0x33d/0x480 [ 36.310772] ? __vfs_write+0x117/0x9f0 [ 36.314675] ? vfs_write+0x1fc/0x560 [ 36.318386] ? ksys_write+0x101/0x260 [ 36.322182] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 36.327736] ? page_counter_memparse+0xb5/0x1e0 [ 36.332412] ? page_counter_set_low+0x180/0x180 [ 36.337079] ? cgroup_control+0x180/0x180 [ 36.341230] memory_high_write+0x283/0x310 [ 36.345474] ? mem_cgroup_css_released+0x140/0x140 [ 36.350416] ? lock_acquire+0x1e4/0x540 [ 36.354397] ? __might_fault+0x12b/0x1e0 [ 36.358462] cgroup_file_write+0x31f/0x840 [ 36.362692] ? mem_cgroup_css_released+0x140/0x140 [ 36.367634] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 36.372558] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 36.377564] kernfs_fop_write+0x2ba/0x480 [ 36.381714] __vfs_write+0x117/0x9f0 [ 36.385435] ? kernfs_fop_open+0x1020/0x1020 [ 36.389843] ? kernel_read+0x120/0x120 [ 36.393732] ? lock_release+0xa30/0xa30 [ 36.397871] ? check_same_owner+0x340/0x340 [ 36.402194] ? rcu_note_context_switch+0x730/0x730 [ 36.407122] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 36.413617] ? __sb_start_write+0x17f/0x300 [ 36.417964] vfs_write+0x1fc/0x560 [ 36.421707] ksys_write+0x101/0x260 [ 36.425991] ? __ia32_sys_read+0xb0/0xb0 [ 36.430041] __x64_sys_write+0x73/0xb0 [ 36.434178] do_syscall_64+0x1b9/0x820 [ 36.439254] ? syscall_return_slowpath+0x5e0/0x5e0 [ 36.444477] ? syscall_return_slowpath+0x31d/0x5e0 [ 36.449404] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 36.454500] ? prepare_exit_to_usermode+0x291/0x3b0 [ 36.459715] ? perf_trace_sys_enter+0xb10/0xb10 [ 36.464572] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 36.469429] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.474631] RIP: 0033:0x4419d9 [ 36.477821] 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 [ 36.497568] RSP: 002b:00007ffd86fe0fd8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 36.505558] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 36.513016] RDX: 0000000000000104 RSI: 0000000020000080 RDI: 0000000000000004 [ 36.520376] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 36.527659] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 36.536266] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 36.544561] Dumping ftrace buffer: [ 36.548096] (ftrace buffer empty) [ 36.551797] Kernel Offset: disabled [ 36.555416] Rebooting in 86400 seconds..