[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 14.244863] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 15.750453] random: sshd: uninitialized urandom read (32 bytes read) [ 15.953641] random: sshd: uninitialized urandom read (32 bytes read) [ 16.762444] random: sshd: uninitialized urandom read (32 bytes read) [ 16.899128] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.56' (ECDSA) to the list of known hosts. [ 22.338921] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 22.415540] ================================================================== [ 22.422938] BUG: KASAN: use-after-free in selinux_sb_copy_data+0x1cd/0x380 [ 22.429924] Write of size 10 at addr ffff8801c7525000 by task syz-executor007/3791 [ 22.437597] [ 22.439199] CPU: 1 PID: 3791 Comm: syz-executor007 Not tainted 4.9.96-g8c01d00 #8 [ 22.446787] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 22.456111] ffff8801b63174c8 ffffffff81eb0b69 ffffea00071d4940 ffff8801c7525000 [ 22.464089] 0000000000000001 ffff8801c7525000 000000000000000a ffff8801b6317500 [ 22.472064] ffffffff8156540b ffff8801c7525000 000000000000000a 0000000000000001 [ 22.480035] Call Trace: [ 22.482595] [] dump_stack+0xc1/0x128 [ 22.487932] [] print_address_description+0x6c/0x234 [ 22.494567] [] kasan_report.cold.6+0x242/0x2fe [ 22.500766] [] ? selinux_sb_copy_data+0x1cd/0x380 [ 22.507240] [] check_memory_region+0x14f/0x1b0 [ 22.513444] [] memcpy+0x37/0x50 [ 22.518343] [] selinux_sb_copy_data+0x1cd/0x380 [ 22.524632] [] security_sb_copy_data+0x7b/0xb0 [ 22.530834] [] parse_security_options+0x36/0x90 [ 22.537121] [] btrfs_mount+0x2f3/0x2bc0 [ 22.542712] [] ? btrfs_remount+0x1360/0x1360 [ 22.548741] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 22.555637] [] ? _find_next_bit.part.0+0xe0/0x120 [ 22.562097] [] ? find_next_bit+0x43/0x50 [ 22.567785] [] ? pcpu_alloc+0x483/0xad0 [ 22.573376] [] ? pcpu_create_chunk+0x430/0x430 [ 22.579579] [] ? __raw_spin_lock_init+0x1c/0x100 [ 22.585953] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 22.592763] [] ? lockdep_init_map+0x105/0x4f0 [ 22.598875] [] ? lockdep_init_map+0x105/0x4f0 [ 22.604992] [] mount_fs+0x28c/0x370 [ 22.610238] [] vfs_kern_mount.part.29+0xd1/0x3d0 [ 22.616612] [] vfs_kern_mount+0x40/0x60 [ 22.622206] [] btrfs_mount+0x40b/0x2bc0 [ 22.627798] [] ? btrfs_remount+0x1360/0x1360 [ 22.633828] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 22.640721] [] ? _find_next_bit.part.0+0xe0/0x120 [ 22.647184] [] ? find_next_bit+0x43/0x50 [ 22.652864] [] ? pcpu_alloc+0x483/0xad0 [ 22.658457] [] ? pcpu_create_chunk+0x430/0x430 [ 22.664670] [] ? __raw_spin_lock_init+0x1c/0x100 [ 22.671048] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 22.677855] [] ? lockdep_init_map+0x105/0x4f0 [ 22.683969] [] ? lockdep_init_map+0x105/0x4f0 [ 22.690082] [] mount_fs+0x28c/0x370 [ 22.695328] [] vfs_kern_mount.part.29+0xd1/0x3d0 [ 22.701702] [] ? ns_capable_common+0x12a/0x150 [ 22.707904] [] do_mount+0x3c9/0x2740 [ 22.713234] [] ? copy_mount_string+0x40/0x40 [ 22.719261] [] ? kasan_unpoison_shadow+0x35/0x50 [ 22.725633] [] ? kasan_kmalloc+0xc7/0xe0 [ 22.731316] [] ? kmem_cache_alloc_trace+0xfd/0x2b0 [ 22.737863] [] ? copy_mount_options+0x5f/0x320 [ 22.744064] [] ? copy_mount_options+0x1e5/0x320 [ 22.750351] [] SyS_mount+0xfe/0x110 [ 22.755596] [] ? copy_mnt_ns+0x8e0/0x8e0 [ 22.761276] [] do_syscall_64+0x1a6/0x490 [ 22.766958] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 22.773852] [ 22.775451] Allocated by task 2041: [ 22.779051] save_stack_trace+0x16/0x20 [ 22.782994] save_stack+0x43/0xd0 [ 22.786415] kasan_kmalloc+0xc7/0xe0 [ 22.790097] kasan_slab_alloc+0x12/0x20 [ 22.794040] kmem_cache_alloc+0xbe/0x290 [ 22.798071] copy_process.part.51+0x3ee5/0x6330 [ 22.802706] _do_fork+0x1b0/0xdc0 [ 22.806128] SyS_clone+0x37/0x50 [ 22.809462] do_syscall_64+0x1a6/0x490 [ 22.813319] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 22.818387] [ 22.819995] Freed by task 2155: [ 22.823245] save_stack_trace+0x16/0x20 [ 22.827190] save_stack+0x43/0xd0 [ 22.830612] kasan_slab_free+0x72/0xc0 [ 22.834481] kmem_cache_free+0xbe/0x310 [ 22.838430] remove_vma+0x11f/0x160 [ 22.842035] exit_mmap+0x2a3/0x3f0 [ 22.845546] mmput+0xf3/0x2d0 [ 22.848624] do_exit+0x906/0x27c0 [ 22.852048] do_group_exit+0x111/0x340 [ 22.855905] SyS_exit_group+0x1d/0x20 [ 22.859674] do_syscall_64+0x1a6/0x490 [ 22.863534] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 22.868604] [ 22.870203] The buggy address belongs to the object at ffff8801c7525000 [ 22.870203] which belongs to the cache vm_area_struct of size 184 [ 22.883087] The buggy address is located 0 bytes inside of [ 22.883087] 184-byte region [ffff8801c7525000, ffff8801c75250b8) [ 22.894755] The buggy address belongs to the page: [ 22.899653] page:ffffea00071d4940 count:1 mapcount:0 mapping: (null) index:0x0 [ 22.907879] flags: 0x8000000000000080(slab) [ 22.912166] page dumped because: kasan: bad access detected [ 22.917842] [ 22.919438] Memory state around the buggy address: [ 22.924337] ffff8801c7524f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 22.931663] ffff8801c7524f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 22.938991] >ffff8801c7525000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 22.946317] ^ [ 22.949650] ffff8801c7525080: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fb [ 22.956975] ffff8801c7525100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 22.964300] ================================================================== [ 22.971628] Disabling lock debugging due to kernel taint [ 22.977358] Kernel panic - not syncing: panic_on_warn set ... [ 22.977358] [ 22.984701] CPU: 1 PID: 3791 Comm: syz-executor007 Tainted: G B 4.9.96-g8c01d00 #8 [ 22.993506] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.002829] ffff8801b6317428 ffffffff81eb0b69 ffffffff841c492d 00000000ffffffff [ 23.010805] 0000000000000000 0000000000000001 000000000000000a ffff8801b63174e8 [ 23.018775] ffffffff8141f975 0000000041b58ab3 ffffffff841b8030 ffffffff8141f7b6 [ 23.026752] Call Trace: [ 23.029313] [] dump_stack+0xc1/0x128 [ 23.034646] [] panic+0x1bf/0x3bc [ 23.039634] [] ? add_taint.cold.6+0x16/0x16 [ 23.045576] [] ? ___preempt_schedule+0x16/0x18 [ 23.051778] [] kasan_end_report+0x47/0x4f [ 23.057545] [] kasan_report.cold.6+0x76/0x2fe [ 23.063663] [] ? selinux_sb_copy_data+0x1cd/0x380 [ 23.070125] [] check_memory_region+0x14f/0x1b0 [ 23.076325] [] memcpy+0x37/0x50 [ 23.081223] [] selinux_sb_copy_data+0x1cd/0x380 [ 23.087512] [] security_sb_copy_data+0x7b/0xb0 [ 23.093719] [] parse_security_options+0x36/0x90 [ 23.100008] [] btrfs_mount+0x2f3/0x2bc0 [ 23.105601] [] ? btrfs_remount+0x1360/0x1360 [ 23.111634] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 23.118529] [] ? _find_next_bit.part.0+0xe0/0x120 [ 23.124988] [] ? find_next_bit+0x43/0x50 [ 23.130667] [] ? pcpu_alloc+0x483/0xad0 [ 23.136260] [] ? pcpu_create_chunk+0x430/0x430 [ 23.142462] [] ? __raw_spin_lock_init+0x1c/0x100 [ 23.148851] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 23.155664] [] ? lockdep_init_map+0x105/0x4f0 [ 23.161779] [] ? lockdep_init_map+0x105/0x4f0 [ 23.167896] [] mount_fs+0x28c/0x370 [ 23.173142] [] vfs_kern_mount.part.29+0xd1/0x3d0 [ 23.179517] [] vfs_kern_mount+0x40/0x60 [ 23.185112] [] btrfs_mount+0x40b/0x2bc0 [ 23.190706] [] ? btrfs_remount+0x1360/0x1360 [ 23.196735] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 23.203635] [] ? _find_next_bit.part.0+0xe0/0x120 [ 23.210097] [] ? find_next_bit+0x43/0x50 [ 23.215780] [] ? pcpu_alloc+0x483/0xad0 [ 23.221373] [] ? pcpu_create_chunk+0x430/0x430 [ 23.227574] [] ? __raw_spin_lock_init+0x1c/0x100 [ 23.233948] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 23.240758] [] ? lockdep_init_map+0x105/0x4f0 [ 23.246872] [] ? lockdep_init_map+0x105/0x4f0 [ 23.252996] [] mount_fs+0x28c/0x370 [ 23.258243] [] vfs_kern_mount.part.29+0xd1/0x3d0 [ 23.264618] [] ? ns_capable_common+0x12a/0x150 [ 23.270818] [] do_mount+0x3c9/0x2740 [ 23.276151] [] ? copy_mount_string+0x40/0x40 [ 23.282179] [] ? kasan_unpoison_shadow+0x35/0x50 [ 23.288552] [] ? kasan_kmalloc+0xc7/0xe0 [ 23.294236] [] ? kmem_cache_alloc_trace+0xfd/0x2b0 [ 23.300784] [] ? copy_mount_options+0x5f/0x320 [ 23.306986] [] ? copy_mount_options+0x1e5/0x320 [ 23.313271] [] SyS_mount+0xfe/0x110 [ 23.318520] [] ? copy_mnt_ns+0x8e0/0x8e0 [ 23.324201] [] do_syscall_64+0x1a6/0x490 [ 23.329880] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 23.337174] Dumping ftrace buffer: [ 23.340687] (ftrace buffer empty) [ 23.344370] Kernel Offset: disabled [ 23.347967] Rebooting in 86400 seconds..