Warning: Permanently added '10.128.1.55' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 535.282337] audit: type=1400 audit(1601291568.002:8): avc: denied { execmem } for pid=6360 comm="syz-executor659" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 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 [ 535.779529] ================================================================== [ 535.787185] BUG: KASAN: use-after-free in __vb2_perform_fileio+0xce9/0xda0 [ 535.794183] Read of size 4 at addr ffff88809704e7dc by task syz-executor659/6406 [ 535.801695] [ 535.803317] CPU: 1 PID: 6406 Comm: syz-executor659 Not tainted 4.14.198-syzkaller #0 [ 535.811173] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 535.820508] Call Trace: [ 535.823194] dump_stack+0x1b2/0x283 [ 535.826853] print_address_description.cold+0x54/0x1d3 [ 535.832126] kasan_report_error.cold+0x8a/0x194 [ 535.836806] ? __vb2_perform_fileio+0xce9/0xda0 [ 535.841463] __asan_report_load4_noabort+0x68/0x70 [ 535.846373] ? __vb2_perform_fileio+0xce9/0xda0 [ 535.851021] __vb2_perform_fileio+0xce9/0xda0 [ 535.855517] ? __vb2_init_fileio+0xa90/0xa90 [ 535.859904] vb2_fop_read+0x1ef/0x3d0 [ 535.863685] ? vb2_fop_write+0x3d0/0x3d0 [ 535.867784] v4l2_read+0x19a/0x200 [ 535.871347] do_iter_read+0x3eb/0x5b0 [ 535.875188] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 535.879865] vfs_readv+0xc8/0x120 [ 535.883297] ? compat_rw_copy_check_uvector+0x320/0x320 [ 535.888656] ? __handle_mm_fault+0x80f/0x4620 [ 535.893183] ? __do_page_fault+0x5a0/0xb50 [ 535.897436] ? lock_downgrade+0x740/0x740 [ 535.901586] do_readv+0xfc/0x2c0 [ 535.904949] ? vfs_readv+0x120/0x120 [ 535.908640] ? __do_page_fault+0x19a/0xb50 [ 535.912851] ? do_syscall_64+0x4c/0x640 [ 535.916803] ? do_readv+0x2c0/0x2c0 [ 535.920407] do_syscall_64+0x1d5/0x640 [ 535.924311] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 535.929477] RIP: 0033:0x444ff9 [ 535.932644] RSP: 002b:00007fffc17d94e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 [ 535.940336] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444ff9 [ 535.947609] RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000003 [ 535.954856] RBP: 0000000000082d07 R08: 0000000000000004 R09: 00000000004002e0 [ 535.962104] R10: 000000000000000f R11: 0000000000000246 R12: 0000000000402110 [ 535.969352] R13: 00000000004021a0 R14: 0000000000000000 R15: 0000000000000000 [ 535.976605] [ 535.978211] Allocated by task 6404: [ 535.981818] kasan_kmalloc+0xeb/0x160 [ 535.985612] kmem_cache_alloc_trace+0x131/0x3d0 [ 535.990258] __vb2_init_fileio+0x17f/0xa90 [ 535.994470] __vb2_perform_fileio+0x993/0xda0 [ 535.998960] vb2_fop_read+0x1ef/0x3d0 [ 536.002739] v4l2_read+0x19a/0x200 [ 536.006258] do_iter_read+0x3eb/0x5b0 [ 536.010035] vfs_readv+0xc8/0x120 [ 536.013483] do_readv+0xfc/0x2c0 [ 536.016828] do_syscall_64+0x1d5/0x640 [ 536.020694] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 536.025856] [ 536.027460] Freed by task 6405: [ 536.030716] kasan_slab_free+0xc3/0x1a0 [ 536.034668] kfree+0xc9/0x250 [ 536.037750] __vb2_cleanup_fileio+0xf5/0x150 [ 536.042134] vb2_core_queue_release+0x17/0x70 [ 536.046624] _vb2_fop_release+0x1c1/0x280 [ 536.050788] vivid_fop_release+0x17d/0x6b6 [ 536.055002] v4l2_release+0xf4/0x190 [ 536.058712] __fput+0x25f/0x7a0 [ 536.062002] task_work_run+0x11f/0x190 [ 536.065906] do_exit+0xa08/0x27f0 [ 536.069341] do_group_exit+0x100/0x2e0 [ 536.073210] SyS_exit_group+0x19/0x20 [ 536.076987] do_syscall_64+0x1d5/0x640 [ 536.080853] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 536.086042] [ 536.087653] The buggy address belongs to the object at ffff88809704e4c0 [ 536.087653] which belongs to the cache kmalloc-1024 of size 1024 [ 536.100465] The buggy address is located 796 bytes inside of [ 536.100465] 1024-byte region [ffff88809704e4c0, ffff88809704e8c0) [ 536.112433] The buggy address belongs to the page: [ 536.117340] page:ffffea00025c1380 count:1 mapcount:0 mapping:ffff88809704e040 index:0x0 compound_mapcount: 0 [ 536.127285] flags: 0xfffe0000008100(slab|head) [ 536.131850] raw: 00fffe0000008100 ffff88809704e040 0000000000000000 0000000100000007 [ 536.139709] raw: ffffea00025d4020 ffffea00025d3da0 ffff88812fe50ac0 0000000000000000 [ 536.147575] page dumped because: kasan: bad access detected [ 536.153281] [ 536.154885] Memory state around the buggy address: [ 536.159794] ffff88809704e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 536.167134] ffff88809704e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 536.174476] >ffff88809704e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 536.181809] ^ [ 536.188016] ffff88809704e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 536.195350] ffff88809704e880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 536.202689] ================================================================== [ 536.210030] Disabling lock debugging due to kernel taint [ 536.216405] Kernel panic - not syncing: panic_on_warn set ... [ 536.216405] [ 536.223768] CPU: 1 PID: 6406 Comm: syz-executor659 Tainted: G B 4.14.198-syzkaller #0 [ 536.232855] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 536.242196] Call Trace: [ 536.244764] dump_stack+0x1b2/0x283 [ 536.248386] panic+0x1f9/0x42d [ 536.251557] ? add_taint.cold+0x16/0x16 [ 536.255508] ? ___preempt_schedule+0x16/0x18 [ 536.259893] kasan_end_report+0x43/0x49 [ 536.263844] kasan_report_error.cold+0xa7/0x194 [ 536.268513] ? __vb2_perform_fileio+0xce9/0xda0 [ 536.273157] __asan_report_load4_noabort+0x68/0x70 [ 536.278061] ? __vb2_perform_fileio+0xce9/0xda0 [ 536.282706] __vb2_perform_fileio+0xce9/0xda0 [ 536.287178] ? __vb2_init_fileio+0xa90/0xa90 [ 536.291586] vb2_fop_read+0x1ef/0x3d0 [ 536.295361] ? vb2_fop_write+0x3d0/0x3d0 [ 536.299415] v4l2_read+0x19a/0x200 [ 536.302932] do_iter_read+0x3eb/0x5b0 [ 536.306721] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 536.311370] vfs_readv+0xc8/0x120 [ 536.314795] ? compat_rw_copy_check_uvector+0x320/0x320 [ 536.320134] ? __handle_mm_fault+0x80f/0x4620 [ 536.324609] ? __do_page_fault+0x5a0/0xb50 [ 536.328841] ? lock_downgrade+0x740/0x740 [ 536.332968] do_readv+0xfc/0x2c0 [ 536.336326] ? vfs_readv+0x120/0x120 [ 536.340016] ? __do_page_fault+0x19a/0xb50 [ 536.344228] ? do_syscall_64+0x4c/0x640 [ 536.348177] ? do_readv+0x2c0/0x2c0 [ 536.352126] do_syscall_64+0x1d5/0x640 [ 536.356011] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 536.361178] RIP: 0033:0x444ff9 [ 536.364342] RSP: 002b:00007fffc17d94e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 [ 536.372721] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444ff9 [ 536.379966] RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000003 [ 536.387235] RBP: 0000000000082d07 R08: 0000000000000004 R09: 00000000004002e0 [ 536.394498] R10: 000000000000000f R11: 0000000000000246 R12: 0000000000402110 [ 536.401761] R13: 00000000004021a0 R14: 0000000000000000 R15: 0000000000000000 [ 536.410306] Kernel Offset: disabled [ 536.413922] Rebooting in 86400 seconds..