[ 39.592751][ T26] audit: type=1800 audit(1556894315.147:27): pid=7632 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [ 39.613436][ T26] audit: type=1800 audit(1556894315.147:28): pid=7632 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2417 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 40.763765][ T26] audit: type=1800 audit(1556894316.397:29): pid=7632 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 [....] startpar: service(s) returned failure: ssh ...[?25l[?1c7[FAIL8[?25h[?0c failed! Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.122' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 51.754945][ T7860] ================================================================== [ 51.763318][ T7860] BUG: KASAN: use-after-free in __vb2_perform_fileio+0x1065/0x1140 [ 51.771255][ T7860] Read of size 4 at addr ffff8880a915555c by task syz-executor283/7860 [ 51.779660][ T7860] [ 51.782032][ T7860] CPU: 0 PID: 7860 Comm: syz-executor283 Not tainted 5.1.0-rc7+ #97 [ 51.790137][ T7860] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.800288][ T7860] Call Trace: [ 51.803599][ T7860] dump_stack+0x172/0x1f0 [ 51.807969][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 51.814073][ T7860] print_address_description.cold+0x7c/0x20d [ 51.820064][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 51.825626][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 51.831199][ T7860] kasan_report.cold+0x1b/0x40 [ 51.836259][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 51.842026][ T7860] __asan_report_load4_noabort+0x14/0x20 [ 51.847751][ T7860] __vb2_perform_fileio+0x1065/0x1140 [ 51.853239][ T7860] ? aa_path_link+0x460/0x460 [ 51.857987][ T7860] ? vb2_thread_start+0x370/0x370 [ 51.863232][ T7860] ? fsnotify+0x811/0xbc0 [ 51.867572][ T7860] vb2_read+0x3b/0x50 [ 51.871568][ T7860] vb2_fop_read+0x212/0x410 [ 51.876222][ T7860] ? vb2_fop_write+0x410/0x410 [ 51.881251][ T7860] v4l2_read+0x1ce/0x230 [ 51.885582][ T7860] __vfs_read+0x8d/0x110 [ 51.889837][ T7860] ? v4l2_write+0x230/0x230 [ 51.894362][ T7860] vfs_read+0x194/0x3e0 [ 51.898565][ T7860] ksys_read+0x14f/0x2d0 [ 51.902924][ T7860] ? kernel_write+0x120/0x120 [ 51.907678][ T7860] ? do_fast_syscall_32+0xd1/0xc98 [ 51.912966][ T7860] ? entry_SYSENTER_compat+0x70/0x7f [ 51.918308][ T7860] ? do_fast_syscall_32+0xd1/0xc98 [ 51.923540][ T7860] __ia32_sys_read+0x71/0xb0 [ 51.928315][ T7860] do_fast_syscall_32+0x281/0xc98 [ 51.933469][ T7860] entry_SYSENTER_compat+0x70/0x7f [ 51.938760][ T7860] RIP: 0023:0xf7fe0849 [ 51.942842][ T7860] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 51.962452][ T7860] RSP: 002b:00000000ffca08ec EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 51.971092][ T7860] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000100 [ 51.979118][ T7860] RDX: 00000000000000f8 RSI: 0000000000000001 RDI: 00000000ffca0a04 [ 51.987098][ T7860] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 51.995293][ T7860] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 52.003292][ T7860] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 52.011348][ T7860] [ 52.013833][ T7860] Allocated by task 7860: [ 52.018190][ T7860] save_stack+0x45/0xd0 [ 52.022439][ T7860] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 52.028233][ T7860] kasan_kmalloc+0x9/0x10 [ 52.032770][ T7860] kmem_cache_alloc_trace+0x151/0x760 [ 52.038148][ T7860] __vb2_init_fileio+0x1cb/0xbe0 [ 52.043091][ T7860] __vb2_perform_fileio+0xc01/0x1140 [ 52.048444][ T7860] vb2_read+0x3b/0x50 [ 52.052440][ T7860] vb2_fop_read+0x212/0x410 [ 52.057003][ T7860] v4l2_read+0x1ce/0x230 [ 52.061265][ T7860] __vfs_read+0x8d/0x110 [ 52.066003][ T7860] vfs_read+0x194/0x3e0 [ 52.074142][ T7860] ksys_read+0x14f/0x2d0 [ 52.078406][ T7860] __ia32_sys_read+0x71/0xb0 [ 52.083109][ T7860] do_fast_syscall_32+0x281/0xc98 [ 52.088150][ T7860] entry_SYSENTER_compat+0x70/0x7f [ 52.093272][ T7860] [ 52.095597][ T7860] Freed by task 7859: [ 52.099712][ T7860] save_stack+0x45/0xd0 [ 52.103951][ T7860] __kasan_slab_free+0x102/0x150 [ 52.109003][ T7860] kasan_slab_free+0xe/0x10 [ 52.113554][ T7860] kfree+0xcf/0x230 [ 52.117379][ T7860] __vb2_cleanup_fileio+0x100/0x170 [ 52.122755][ T7860] vb2_core_queue_release+0x20/0x80 [ 52.128373][ T7860] _vb2_fop_release+0x1cf/0x2a0 [ 52.133521][ T7860] vb2_fop_release+0x75/0xc0 [ 52.138445][ T7860] vivid_fop_release+0x18e/0x430 [ 52.143416][ T7860] v4l2_release+0x224/0x3a0 [ 52.148504][ T7860] __fput+0x2e5/0x8d0 [ 52.152515][ T7860] ____fput+0x16/0x20 [ 52.156643][ T7860] task_work_run+0x14a/0x1c0 [ 52.162038][ T7860] do_exit+0x90a/0x2fa0 [ 52.166633][ T7860] do_group_exit+0x135/0x370 [ 52.171744][ T7860] __ia32_sys_exit_group+0x44/0x50 [ 52.177680][ T7860] do_fast_syscall_32+0x281/0xc98 [ 52.182985][ T7860] entry_SYSENTER_compat+0x70/0x7f [ 52.188646][ T7860] [ 52.191136][ T7860] The buggy address belongs to the object at ffff8880a9155240 [ 52.191136][ T7860] which belongs to the cache kmalloc-1k of size 1024 [ 52.205896][ T7860] The buggy address is located 796 bytes inside of [ 52.205896][ T7860] 1024-byte region [ffff8880a9155240, ffff8880a9155640) [ 52.220045][ T7860] The buggy address belongs to the page: [ 52.225831][ T7860] page:ffffea0002a45500 count:1 mapcount:0 mapping:ffff8880aa400ac0 index:0x0 compound_mapcount: 0 [ 52.236536][ T7860] flags: 0x1fffc0000010200(slab|head) [ 52.242035][ T7860] raw: 01fffc0000010200 ffffea0002480908 ffffea0002348208 ffff8880aa400ac0 [ 52.250651][ T7860] raw: 0000000000000000 ffff8880a9154040 0000000100000007 0000000000000000 [ 52.259253][ T7860] page dumped because: kasan: bad access detected [ 52.265695][ T7860] [ 52.268032][ T7860] Memory state around the buggy address: [ 52.274155][ T7860] ffff8880a9155400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.282231][ T7860] ffff8880a9155480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.290302][ T7860] >ffff8880a9155500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.298464][ T7860] ^ [ 52.305399][ T7860] ffff8880a9155580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.313529][ T7860] ffff8880a9155600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 52.329136][ T7860] ================================================================== [ 52.337192][ T7860] Disabling lock debugging due to kernel taint [ 52.345352][ T7860] Kernel panic - not syncing: panic_on_warn set ... [ 52.352137][ T7860] CPU: 0 PID: 7860 Comm: syz-executor283 Tainted: G B 5.1.0-rc7+ #97 [ 52.361502][ T7860] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.371642][ T7860] Call Trace: [ 52.374995][ T7860] dump_stack+0x172/0x1f0 [ 52.379338][ T7860] panic+0x2cb/0x65c [ 52.383248][ T7860] ? __warn_printk+0xf3/0xf3 [ 52.387936][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 52.393648][ T7860] ? preempt_schedule+0x4b/0x60 [ 52.398610][ T7860] ? ___preempt_schedule+0x16/0x18 [ 52.403845][ T7860] ? trace_hardirqs_on+0x5e/0x230 [ 52.409183][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 52.414777][ T7860] end_report+0x47/0x4f [ 52.418948][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 52.424502][ T7860] kasan_report.cold+0xe/0x40 [ 52.429195][ T7860] ? __vb2_perform_fileio+0x1065/0x1140 [ 52.434950][ T7860] __asan_report_load4_noabort+0x14/0x20 [ 52.440598][ T7860] __vb2_perform_fileio+0x1065/0x1140 [ 52.445985][ T7860] ? aa_path_link+0x460/0x460 [ 52.450914][ T7860] ? vb2_thread_start+0x370/0x370 [ 52.455945][ T7860] ? fsnotify+0x811/0xbc0 [ 52.460282][ T7860] vb2_read+0x3b/0x50 [ 52.464270][ T7860] vb2_fop_read+0x212/0x410 [ 52.469151][ T7860] ? vb2_fop_write+0x410/0x410 [ 52.473978][ T7860] v4l2_read+0x1ce/0x230 [ 52.478832][ T7860] __vfs_read+0x8d/0x110 [ 52.483430][ T7860] ? v4l2_write+0x230/0x230 [ 52.487927][ T7860] vfs_read+0x194/0x3e0 [ 52.492081][ T7860] ksys_read+0x14f/0x2d0 [ 52.496318][ T7860] ? kernel_write+0x120/0x120 [ 52.500987][ T7860] ? do_fast_syscall_32+0xd1/0xc98 [ 52.506711][ T7860] ? entry_SYSENTER_compat+0x70/0x7f [ 52.512115][ T7860] ? do_fast_syscall_32+0xd1/0xc98 [ 52.517433][ T7860] __ia32_sys_read+0x71/0xb0 [ 52.522113][ T7860] do_fast_syscall_32+0x281/0xc98 [ 52.527249][ T7860] entry_SYSENTER_compat+0x70/0x7f [ 52.532468][ T7860] RIP: 0023:0xf7fe0849 [ 52.536814][ T7860] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 52.557094][ T7860] RSP: 002b:00000000ffca08ec EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 52.565750][ T7860] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000100 [ 52.573737][ T7860] RDX: 00000000000000f8 RSI: 0000000000000001 RDI: 00000000ffca0a04 [ 52.581781][ T7860] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 52.589908][ T7860] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 52.598089][ T7860] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 52.607305][ T7860] Kernel Offset: disabled [ 52.611705][ T7860] Rebooting in 86400 seconds..