[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 32.737393] kauditd_printk_skb: 8 callbacks suppressed [ 32.737403] audit: type=1800 audit(1552175306.500:29): pid=7287 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 32.767811] audit: type=1800 audit(1552175306.500:30): pid=7287 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.35' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 43.727024] ================================================================== [ 43.734935] BUG: KASAN: use-after-free in __vb2_perform_fileio+0x1065/0x1140 [ 43.742120] Read of size 4 at addr ffff88808eaf0c1c by task syz-executor580/7443 [ 43.749628] [ 43.751250] CPU: 0 PID: 7443 Comm: syz-executor580 Not tainted 5.0.0+ #14 [ 43.758151] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.767482] Call Trace: [ 43.770193] dump_stack+0x172/0x1f0 [ 43.773805] ? __vb2_perform_fileio+0x1065/0x1140 [ 43.778632] print_address_description.cold+0x7c/0x20d [ 43.783889] ? __vb2_perform_fileio+0x1065/0x1140 [ 43.788711] ? __vb2_perform_fileio+0x1065/0x1140 [ 43.793535] kasan_report.cold+0x1b/0x40 [ 43.797580] ? __vb2_perform_fileio+0x1065/0x1140 [ 43.802406] __asan_report_load4_noabort+0x14/0x20 [ 43.807322] __vb2_perform_fileio+0x1065/0x1140 [ 43.812004] ? aa_path_link+0x460/0x460 [ 43.815965] ? vb2_thread_start+0x370/0x370 [ 43.820279] ? fsnotify+0x811/0xbc0 [ 43.823905] vb2_read+0x3b/0x50 [ 43.827204] vb2_fop_read+0x212/0x410 [ 43.831012] ? vb2_fop_write+0x410/0x410 [ 43.835424] v4l2_read+0x1ce/0x230 [ 43.838947] __vfs_read+0x8d/0x110 [ 43.842466] ? v4l2_write+0x230/0x230 [ 43.846248] vfs_read+0x194/0x3e0 [ 43.849683] ksys_read+0xea/0x1f0 [ 43.853119] ? kernel_write+0x120/0x120 [ 43.857076] ? do_syscall_64+0x26/0x610 [ 43.861478] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 43.866829] ? do_syscall_64+0x26/0x610 [ 43.870795] __x64_sys_read+0x73/0xb0 [ 43.874577] do_syscall_64+0x103/0x610 [ 43.878448] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 43.883621] RIP: 0033:0x444dc9 [ 43.886795] Code: e8 ac e8 ff ff 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 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 43.905673] RSP: 002b:00007ffe3126c128 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 43.913360] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000444dc9 [ 43.920613] RDX: 0000000000000009 RSI: 0000000020000100 RDI: 0000000000000003 [ 43.927862] RBP: 00000000006cf018 R08: 0000000000000004 R09: 00000000004002e0 [ 43.935111] R10: 000000000000000f R11: 0000000000000246 R12: 0000000000401f60 [ 43.942730] R13: 0000000000401ff0 R14: 0000000000000000 R15: 0000000000000000 [ 43.949996] [ 43.951611] Allocated by task 7443: [ 43.955228] save_stack+0x45/0xd0 [ 43.958661] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 43.963569] kasan_kmalloc+0x9/0x10 [ 43.967178] kmem_cache_alloc_trace+0x151/0x760 [ 43.971829] __vb2_init_fileio+0x1cb/0xbe0 [ 43.976049] __vb2_perform_fileio+0xc01/0x1140 [ 43.980610] vb2_read+0x3b/0x50 [ 43.983872] vb2_fop_read+0x212/0x410 [ 43.987649] v4l2_read+0x1ce/0x230 [ 43.991176] __vfs_read+0x8d/0x110 [ 43.994702] vfs_read+0x194/0x3e0 [ 43.998148] ksys_read+0xea/0x1f0 [ 44.001580] __x64_sys_read+0x73/0xb0 [ 44.005360] do_syscall_64+0x103/0x610 [ 44.009230] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.014394] [ 44.016002] Freed by task 7450: [ 44.019268] save_stack+0x45/0xd0 [ 44.022723] __kasan_slab_free+0x102/0x150 [ 44.026942] kasan_slab_free+0xe/0x10 [ 44.030726] kfree+0xcf/0x230 [ 44.033821] __vb2_cleanup_fileio+0x100/0x170 [ 44.038295] vb2_core_queue_release+0x20/0x80 [ 44.042772] _vb2_fop_release+0x1cf/0x2a0 [ 44.047261] vb2_fop_release+0x75/0xc0 [ 44.051135] vivid_fop_release+0x18e/0x430 [ 44.055354] v4l2_release+0x224/0x3a0 [ 44.059135] __fput+0x2e5/0x8d0 [ 44.062396] ____fput+0x16/0x20 [ 44.065655] task_work_run+0x14a/0x1c0 [ 44.069522] exit_to_usermode_loop+0x273/0x2c0 [ 44.074087] do_syscall_64+0x52d/0x610 [ 44.077953] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.083113] [ 44.084726] The buggy address belongs to the object at ffff88808eaf0900 [ 44.084726] which belongs to the cache kmalloc-1k of size 1024 [ 44.097362] The buggy address is located 796 bytes inside of [ 44.097362] 1024-byte region [ffff88808eaf0900, ffff88808eaf0d00) [ 44.109297] The buggy address belongs to the page: [ 44.114236] page:ffffea00023abc00 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0 [ 44.124185] flags: 0x1fffc0000010200(slab|head) [ 44.128858] raw: 01fffc0000010200 ffffea0002393f88 ffffea00023ae488 ffff88812c3f0ac0 [ 44.136721] raw: 0000000000000000 ffff88808eaf0000 0000000100000007 0000000000000000 [ 44.144577] page dumped because: kasan: bad access detected [ 44.150267] [ 44.151870] Memory state around the buggy address: [ 44.157124] ffff88808eaf0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.164464] ffff88808eaf0b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.171802] >ffff88808eaf0c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.179149] ^ [ 44.183273] ffff88808eaf0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.190611] ffff88808eaf0d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 44.197944] ================================================================== [ 44.205288] Disabling lock debugging due to kernel taint [ 44.211216] Kernel panic - not syncing: panic_on_warn set ... [ 44.217102] CPU: 0 PID: 7443 Comm: syz-executor580 Tainted: G B 5.0.0+ #14 [ 44.225391] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.234721] Call Trace: [ 44.237293] dump_stack+0x172/0x1f0 [ 44.240901] panic+0x2cb/0x65c [ 44.244073] ? __warn_printk+0xf3/0xf3 [ 44.247943] ? __vb2_perform_fileio+0x1065/0x1140 [ 44.252764] ? preempt_schedule+0x4b/0x60 [ 44.256973] ? ___preempt_schedule+0x16/0x18 [ 44.261361] ? trace_hardirqs_on+0x5e/0x230 [ 44.265667] ? __vb2_perform_fileio+0x1065/0x1140 [ 44.270496] end_report+0x47/0x4f [ 44.273930] ? __vb2_perform_fileio+0x1065/0x1140 [ 44.278760] kasan_report.cold+0xe/0x40 [ 44.282715] ? __vb2_perform_fileio+0x1065/0x1140 [ 44.287903] __asan_report_load4_noabort+0x14/0x20 [ 44.292830] __vb2_perform_fileio+0x1065/0x1140 [ 44.297479] ? aa_path_link+0x460/0x460 [ 44.301436] ? vb2_thread_start+0x370/0x370 [ 44.305735] ? fsnotify+0x811/0xbc0 [ 44.309345] vb2_read+0x3b/0x50 [ 44.312607] vb2_fop_read+0x212/0x410 [ 44.316390] ? vb2_fop_write+0x410/0x410 [ 44.320447] v4l2_read+0x1ce/0x230 [ 44.323970] __vfs_read+0x8d/0x110 [ 44.327493] ? v4l2_write+0x230/0x230 [ 44.331275] vfs_read+0x194/0x3e0 [ 44.334708] ksys_read+0xea/0x1f0 [ 44.338154] ? kernel_write+0x120/0x120 [ 44.342120] ? do_syscall_64+0x26/0x610 [ 44.346076] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.351416] ? do_syscall_64+0x26/0x610 [ 44.355371] __x64_sys_read+0x73/0xb0 [ 44.359153] do_syscall_64+0x103/0x610 [ 44.363021] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.368187] RIP: 0033:0x444dc9 [ 44.371364] Code: e8 ac e8 ff ff 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 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 44.390244] RSP: 002b:00007ffe3126c128 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 44.397930] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000444dc9 [ 44.405488] RDX: 0000000000000009 RSI: 0000000020000100 RDI: 0000000000000003 [ 44.412745] RBP: 00000000006cf018 R08: 0000000000000004 R09: 00000000004002e0 [ 44.420010] R10: 000000000000000f R11: 0000000000000246 R12: 0000000000401f60 [ 44.427256] R13: 0000000000401ff0 R14: 0000000000000000 R15: 0000000000000000 [ 44.435338] Kernel Offset: disabled [ 44.438957] Rebooting in 86400 seconds..