[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.957127] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.750151] random: sshd: uninitialized urandom read (32 bytes read) [ 20.184991] random: sshd: uninitialized urandom read (32 bytes read) [ 20.879418] random: sshd: uninitialized urandom read (32 bytes read) [ 21.029502] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.28' (ECDSA) to the list of known hosts. [ 26.480205] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 26.577858] IPVS: ftp: loaded support on port[0] = 21 [ 26.603566] ================================================================== [ 26.610959] BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 [ 26.617690] Read of size 8 at addr ffff8801d7cd7090 by task syz-executor544/4454 [ 26.625192] [ 26.626799] CPU: 0 PID: 4454 Comm: syz-executor544 Not tainted 4.18.0-rc3-next-20180706+ #1 [ 26.635262] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.644592] Call Trace: [ 26.647162] dump_stack+0x1c9/0x2b4 [ 26.650769] ? dump_stack_print_info.cold.2+0x52/0x52 [ 26.655948] ? printk+0xa7/0xcf [ 26.659204] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 26.663938] ? find_first_bit+0xf7/0x100 [ 26.667978] print_address_description+0x6c/0x20b [ 26.672805] ? find_first_bit+0xf7/0x100 [ 26.676844] kasan_report.cold.7+0x242/0x30d [ 26.681231] __asan_report_load8_noabort+0x14/0x20 [ 26.686139] find_first_bit+0xf7/0x100 [ 26.690005] shrink_slab+0x5d0/0xdb0 [ 26.693697] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 26.699215] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 26.704828] ? shrink_active_list+0x1830/0x1830 [ 26.709486] ? save_stack+0xa9/0xd0 [ 26.713096] ? save_stack+0x43/0xd0 [ 26.716700] ? kernfs_fop_open+0xa7f/0x1020 [ 26.720999] ? do_dentry_open+0xa7d/0x11c0 [ 26.725216] ? trace_hardirqs_on+0x10/0x10 [ 26.729442] shrink_node+0x429/0x16a0 [ 26.733228] ? shrink_node_memcg+0x18f0/0x18f0 [ 26.737797] ? kvm_clock_read+0x25/0x30 [ 26.741759] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 26.746755] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 26.751232] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 26.756229] do_try_to_free_pages+0x3e7/0x1290 [ 26.760792] ? shrink_node+0x16a0/0x16a0 [ 26.764831] ? check_same_owner+0x340/0x340 [ 26.769134] ? trace_hardirqs_on+0x10/0x10 [ 26.773349] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 26.778864] ? _parse_integer+0x13b/0x190 [ 26.782991] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 26.788517] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 26.793685] ? pointer_string+0x1b0/0x1b0 [ 26.797814] ? try_to_free_pages+0xb80/0xb80 [ 26.802221] ? memparse+0x171/0x1d0 [ 26.805826] ? get_options+0x380/0x380 [ 26.809718] ? kasan_kmalloc+0xc4/0xe0 [ 26.813600] ? __kmalloc+0x14e/0x760 [ 26.817292] ? kernfs_fop_write+0x33d/0x480 [ 26.821588] ? __vfs_write+0x117/0x9f0 [ 26.825452] ? vfs_write+0x1fc/0x560 [ 26.829151] ? ksys_write+0x101/0x260 [ 26.832931] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 26.838457] ? page_counter_memparse+0xb5/0x1e0 [ 26.843104] ? page_counter_set_low+0x180/0x180 [ 26.847750] ? cgroup_control+0x180/0x180 [ 26.851887] memory_high_write+0x283/0x310 [ 26.856111] ? mem_cgroup_css_released+0x140/0x140 [ 26.861029] ? lock_acquire+0x1e4/0x540 [ 26.864985] ? __might_fault+0x12b/0x1e0 [ 26.869026] cgroup_file_write+0x31f/0x840 [ 26.873239] ? mem_cgroup_css_released+0x140/0x140 [ 26.878146] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 26.883065] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 26.887971] kernfs_fop_write+0x2ba/0x480 [ 26.892098] __vfs_write+0x117/0x9f0 [ 26.895797] ? kernfs_fop_open+0x1020/0x1020 [ 26.900195] ? kernel_read+0x120/0x120 [ 26.904070] ? lock_release+0xa30/0xa30 [ 26.908022] ? check_same_owner+0x340/0x340 [ 26.912322] ? rcu_note_context_switch+0x730/0x730 [ 26.917244] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 26.923136] ? __sb_start_write+0x17f/0x300 [ 26.927450] vfs_write+0x1fc/0x560 [ 26.930978] ksys_write+0x101/0x260 [ 26.934586] ? __ia32_sys_read+0xb0/0xb0 [ 26.938628] __x64_sys_write+0x73/0xb0 [ 26.942505] do_syscall_64+0x1b9/0x820 [ 26.946372] ? syscall_return_slowpath+0x5e0/0x5e0 [ 26.951282] ? syscall_return_slowpath+0x31d/0x5e0 [ 26.956192] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 26.961188] ? prepare_exit_to_usermode+0x291/0x3b0 [ 26.966183] ? perf_trace_sys_enter+0xb10/0xb10 [ 26.970829] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.975654] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 26.980838] RIP: 0033:0x4419d9 [ 26.984011] 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 [ 27.003131] RSP: 002b:00007ffcc11b15d8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 27.010822] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 27.018070] RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000004 [ 27.025317] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 27.032566] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 27.039813] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 27.047064] [ 27.048672] Allocated by task 4453: [ 27.052292] save_stack+0x43/0xd0 [ 27.055730] kasan_kmalloc+0xc4/0xe0 [ 27.059425] __kmalloc_node+0x47/0x70 [ 27.063214] kvmalloc_node+0x65/0xf0 [ 27.066914] mem_cgroup_css_online+0x169/0x3c0 [ 27.071472] online_css+0x10c/0x350 [ 27.075077] cgroup_apply_control_enable+0x777/0xe90 [ 27.080162] cgroup_mkdir+0x88a/0x1170 [ 27.084039] kernfs_iop_mkdir+0x159/0x1e0 [ 27.088163] vfs_mkdir+0x42e/0x6b0 [ 27.091679] do_mkdirat+0x27b/0x310 [ 27.095290] __x64_sys_mkdir+0x5c/0x80 [ 27.099154] do_syscall_64+0x1b9/0x820 [ 27.103030] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 27.108199] [ 27.109801] Freed by task 2885: [ 27.113073] save_stack+0x43/0xd0 [ 27.116512] __kasan_slab_free+0x11a/0x170 [ 27.120721] kasan_slab_free+0xe/0x10 [ 27.124510] kfree+0xd9/0x260 [ 27.127593] single_release+0x8f/0xb0 [ 27.131391] __fput+0x35d/0x930 [ 27.134661] ____fput+0x15/0x20 [ 27.137934] task_work_run+0x1ec/0x2a0 [ 27.141809] exit_to_usermode_loop+0x313/0x370 [ 27.146378] do_syscall_64+0x6be/0x820 [ 27.150242] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 27.155405] [ 27.157018] The buggy address belongs to the object at ffff8801d7cd7080 [ 27.157018] which belongs to the cache kmalloc-32 of size 32 [ 27.169489] The buggy address is located 16 bytes inside of [ 27.169489] 32-byte region [ffff8801d7cd7080, ffff8801d7cd70a0) [ 27.181174] The buggy address belongs to the page: [ 27.186088] page:ffffea00075f35c0 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d7cd7fc1 [ 27.195513] flags: 0x2fffc0000000100(slab) [ 27.199763] raw: 02fffc0000000100 ffffea00075d5348 ffffea00075d9288 ffff8801da8001c0 [ 27.207625] raw: ffff8801d7cd7fc1 ffff8801d7cd7000 0000000100000039 0000000000000000 [ 27.215478] page dumped because: kasan: bad access detected [ 27.221159] [ 27.222761] Memory state around the buggy address: [ 27.227678] ffff8801d7cd6f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 27.235019] ffff8801d7cd7000: 00 03 fc fc fc fc fc fc 00 00 06 fc fc fc fc fc [ 27.242367] >ffff8801d7cd7080: 00 00 05 fc fc fc fc fc 00 00 00 fc fc fc fc fc [ 27.249698] ^ [ 27.253561] ffff8801d7cd7100: 00 00 00 fc fc fc fc fc 00 07 fc fc fc fc fc fc [ 27.260894] ffff8801d7cd7180: 00 00 00 fc fc fc fc fc 00 03 fc fc fc fc fc fc [ 27.268224] ================================================================== [ 27.275692] Kernel panic - not syncing: panic_on_warn set ... [ 27.275692] [ 27.283053] CPU: 0 PID: 4454 Comm: syz-executor544 Tainted: G B 4.18.0-rc3-next-20180706+ #1 [ 27.292904] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.302251] Call Trace: [ 27.304827] dump_stack+0x1c9/0x2b4 [ 27.308445] ? dump_stack_print_info.cold.2+0x52/0x52 [ 27.313618] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 27.318371] panic+0x238/0x4e7 [ 27.321547] ? add_taint.cold.5+0x16/0x16 [ 27.325676] ? do_raw_spin_unlock+0xa7/0x2f0 [ 27.330066] ? find_first_bit+0xf7/0x100 [ 27.334114] kasan_end_report+0x47/0x4f [ 27.338065] kasan_report.cold.7+0x76/0x30d [ 27.342366] __asan_report_load8_noabort+0x14/0x20 [ 27.347275] find_first_bit+0xf7/0x100 [ 27.351143] shrink_slab+0x5d0/0xdb0 [ 27.354837] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 27.360938] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 27.366547] ? shrink_active_list+0x1830/0x1830 [ 27.371197] ? save_stack+0xa9/0xd0 [ 27.374802] ? save_stack+0x43/0xd0 [ 27.378415] ? kernfs_fop_open+0xa7f/0x1020 [ 27.382714] ? do_dentry_open+0xa7d/0x11c0 [ 27.386928] ? trace_hardirqs_on+0x10/0x10 [ 27.391145] shrink_node+0x429/0x16a0 [ 27.394932] ? shrink_node_memcg+0x18f0/0x18f0 [ 27.399493] ? kvm_clock_read+0x25/0x30 [ 27.403457] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 27.408455] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 27.412936] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 27.417936] do_try_to_free_pages+0x3e7/0x1290 [ 27.422502] ? shrink_node+0x16a0/0x16a0 [ 27.426543] ? check_same_owner+0x340/0x340 [ 27.430844] ? trace_hardirqs_on+0x10/0x10 [ 27.435060] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 27.440576] ? _parse_integer+0x13b/0x190 [ 27.444704] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 27.450224] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 27.455394] ? pointer_string+0x1b0/0x1b0 [ 27.459523] ? try_to_free_pages+0xb80/0xb80 [ 27.463911] ? memparse+0x171/0x1d0 [ 27.467517] ? get_options+0x380/0x380 [ 27.471385] ? kasan_kmalloc+0xc4/0xe0 [ 27.475249] ? __kmalloc+0x14e/0x760 [ 27.478943] ? kernfs_fop_write+0x33d/0x480 [ 27.483245] ? __vfs_write+0x117/0x9f0 [ 27.487117] ? vfs_write+0x1fc/0x560 [ 27.490809] ? ksys_write+0x101/0x260 [ 27.494591] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 27.500109] ? page_counter_memparse+0xb5/0x1e0 [ 27.504759] ? page_counter_set_low+0x180/0x180 [ 27.509403] ? cgroup_control+0x180/0x180 [ 27.513532] memory_high_write+0x283/0x310 [ 27.517747] ? mem_cgroup_css_released+0x140/0x140 [ 27.522662] ? lock_acquire+0x1e4/0x540 [ 27.526615] ? __might_fault+0x12b/0x1e0 [ 27.530658] cgroup_file_write+0x31f/0x840 [ 27.534876] ? mem_cgroup_css_released+0x140/0x140 [ 27.539784] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 27.544706] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 27.549622] kernfs_fop_write+0x2ba/0x480 [ 27.553750] __vfs_write+0x117/0x9f0 [ 27.557447] ? kernfs_fop_open+0x1020/0x1020 [ 27.561835] ? kernel_read+0x120/0x120 [ 27.565702] ? lock_release+0xa30/0xa30 [ 27.569657] ? check_same_owner+0x340/0x340 [ 27.573958] ? rcu_note_context_switch+0x730/0x730 [ 27.578870] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 27.584387] ? __sb_start_write+0x17f/0x300 [ 27.588689] vfs_write+0x1fc/0x560 [ 27.592222] ksys_write+0x101/0x260 [ 27.595851] ? __ia32_sys_read+0xb0/0xb0 [ 27.599906] __x64_sys_write+0x73/0xb0 [ 27.603780] do_syscall_64+0x1b9/0x820 [ 27.607646] ? syscall_return_slowpath+0x5e0/0x5e0 [ 27.612559] ? syscall_return_slowpath+0x31d/0x5e0 [ 27.618596] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 27.623590] ? prepare_exit_to_usermode+0x291/0x3b0 [ 27.628583] ? perf_trace_sys_enter+0xb10/0xb10 [ 27.633231] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 27.638056] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 27.643235] RIP: 0033:0x4419d9 [ 27.646412] 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 [ 27.665528] RSP: 002b:00007ffcc11b15d8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 27.673215] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 27.680463] RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000004 [ 27.687727] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 27.694990] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 27.702239] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 27.709949] Dumping ftrace buffer: [ 27.713468] (ftrace buffer empty) [ 27.717155] Kernel Offset: disabled [ 27.720759] Rebooting in 86400 seconds..