[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.168' (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: [ 27.605701] ================================================================== [ 27.613129] BUG: KASAN: use-after-free in __vb2_perform_fileio+0xce9/0xda0 [ 27.620202] Read of size 4 at addr ffff88809641199c by task syz-executor276/7976 [ 27.627708] [ 27.629314] CPU: 1 PID: 7976 Comm: syz-executor276 Not tainted 4.14.244-syzkaller #0 [ 27.637166] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.646545] Call Trace: [ 27.649177] dump_stack+0x1b2/0x281 [ 27.652784] print_address_description.cold+0x54/0x1d3 [ 27.658042] kasan_report_error.cold+0x8a/0x191 [ 27.662700] ? __vb2_perform_fileio+0xce9/0xda0 [ 27.667363] __asan_report_load4_noabort+0x68/0x70 [ 27.672277] ? __vb2_perform_fileio+0xce9/0xda0 [ 27.676918] __vb2_perform_fileio+0xce9/0xda0 [ 27.681390] ? __vb2_init_fileio+0xa90/0xa90 [ 27.685773] ? aa_file_perm+0x304/0xab0 [ 27.689724] vb2_fop_read+0x1ef/0x3d0 [ 27.693503] ? vb2_fop_write+0x3d0/0x3d0 [ 27.697551] v4l2_read+0x19a/0x200 [ 27.701068] __vfs_read+0xe4/0x620 [ 27.704581] ? v4l2_write+0x200/0x200 [ 27.708360] ? __handle_mm_fault+0x80f/0x4620 [ 27.712849] ? vfs_copy_file_range+0x9b0/0x9b0 [ 27.717412] ? common_file_perm+0x3ee/0x580 [ 27.721710] ? __fd_install+0x227/0x5c0 [ 27.725661] ? security_file_permission+0x82/0x1e0 [ 27.730565] ? rw_verify_area+0xe1/0x2a0 [ 27.734603] vfs_read+0x139/0x340 [ 27.738040] SyS_pread64+0x116/0x140 [ 27.741750] ? SyS_write+0x210/0x210 [ 27.745445] ? __do_page_fault+0x159/0xad0 [ 27.749653] ? do_syscall_64+0x4c/0x640 [ 27.753600] ? SyS_write+0x210/0x210 [ 27.757302] do_syscall_64+0x1d5/0x640 [ 27.761167] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.766332] RIP: 0033:0x444279 [ 27.769497] RSP: 002b:00007ffd05c32f08 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 [ 27.777177] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 0000000000444279 [ 27.784498] RDX: 000000000000006a RSI: 0000000020000000 RDI: 0000000000000003 [ 27.791761] RBP: 0000000000000000 R08: 00236f656469762f R09: 0000000000000001 [ 27.799008] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004034e0 [ 27.806258] R13: 0000000000000000 R14: 00007ffd05c32f30 R15: 00007ffd05c32f20 [ 27.813512] [ 27.815122] Allocated by task 7976: [ 27.818784] kasan_kmalloc+0xeb/0x160 [ 27.822563] kmem_cache_alloc_trace+0x131/0x3d0 [ 27.827208] __vb2_init_fileio+0x17f/0xa90 [ 27.831419] __vb2_perform_fileio+0x993/0xda0 [ 27.835907] vb2_fop_read+0x1ef/0x3d0 [ 27.839688] v4l2_read+0x19a/0x200 [ 27.843202] __vfs_read+0xe4/0x620 [ 27.846714] vfs_read+0x139/0x340 [ 27.850148] SyS_pread64+0x116/0x140 [ 27.853846] do_syscall_64+0x1d5/0x640 [ 27.857731] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.862897] [ 27.864501] Freed by task 7979: [ 27.867756] kasan_slab_free+0xc3/0x1a0 [ 27.871721] kfree+0xc9/0x250 [ 27.875081] __vb2_cleanup_fileio+0xf5/0x150 [ 27.879469] vb2_core_queue_release+0x17/0x70 [ 27.883947] _vb2_fop_release+0x1c1/0x280 [ 27.888074] vivid_fop_release+0x17d/0x6c0 [ 27.892284] v4l2_release+0xf4/0x190 [ 27.896000] __fput+0x25f/0x7a0 [ 27.899262] task_work_run+0x11f/0x190 [ 27.903128] do_exit+0xa44/0x2850 [ 27.906648] do_group_exit+0x100/0x2e0 [ 27.910512] SyS_exit_group+0x19/0x20 [ 27.914294] do_syscall_64+0x1d5/0x640 [ 27.918168] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.923521] [ 27.925132] The buggy address belongs to the object at ffff888096411680 [ 27.925132] which belongs to the cache kmalloc-1024 of size 1024 [ 27.938025] The buggy address is located 796 bytes inside of [ 27.938025] 1024-byte region [ffff888096411680, ffff888096411a80) [ 27.949971] The buggy address belongs to the page: [ 27.954877] page:ffffea0002590400 count:1 mapcount:0 mapping:ffff888096410000 index:0xffff888096410900 compound_mapcount: 0 [ 27.966210] flags: 0xfff00000008100(slab|head) [ 27.970767] raw: 00fff00000008100 ffff888096410000 ffff888096410900 0000000100000006 [ 27.978621] raw: ffffea00025afd20 ffffea0002cea4a0 ffff88813fe80ac0 0000000000000000 [ 27.986491] page dumped because: kasan: bad access detected [ 27.992173] [ 27.993774] Memory state around the buggy address: [ 27.998684] ffff888096411880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.006015] ffff888096411900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.013377] >ffff888096411980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.020716] ^ [ 28.024854] ffff888096411a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.032191] ffff888096411a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 28.039542] ================================================================== [ 28.046874] Disabling lock debugging due to kernel taint [ 28.052952] Kernel panic - not syncing: panic_on_warn set ... [ 28.052952] [ 28.060397] CPU: 1 PID: 7976 Comm: syz-executor276 Tainted: G B 4.14.244-syzkaller #0 [ 28.069477] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.079515] Call Trace: [ 28.082095] dump_stack+0x1b2/0x281 [ 28.085862] panic+0x1f9/0x42d [ 28.089031] ? add_taint.cold+0x16/0x16 [ 28.092981] ? ___preempt_schedule+0x16/0x18 [ 28.097381] kasan_end_report+0x43/0x49 [ 28.101395] kasan_report_error.cold+0xa7/0x191 [ 28.106044] ? __vb2_perform_fileio+0xce9/0xda0 [ 28.110697] __asan_report_load4_noabort+0x68/0x70 [ 28.115608] ? __vb2_perform_fileio+0xce9/0xda0 [ 28.120255] __vb2_perform_fileio+0xce9/0xda0 [ 28.124744] ? __vb2_init_fileio+0xa90/0xa90 [ 28.129128] ? aa_file_perm+0x304/0xab0 [ 28.133078] vb2_fop_read+0x1ef/0x3d0 [ 28.136858] ? vb2_fop_write+0x3d0/0x3d0 [ 28.140921] v4l2_read+0x19a/0x200 [ 28.144439] __vfs_read+0xe4/0x620 [ 28.147955] ? v4l2_write+0x200/0x200 [ 28.151820] ? __handle_mm_fault+0x80f/0x4620 [ 28.156317] ? vfs_copy_file_range+0x9b0/0x9b0 [ 28.160878] ? common_file_perm+0x3ee/0x580 [ 28.165175] ? __fd_install+0x227/0x5c0 [ 28.169136] ? security_file_permission+0x82/0x1e0 [ 28.174045] ? rw_verify_area+0xe1/0x2a0 [ 28.178103] vfs_read+0x139/0x340 [ 28.181539] SyS_pread64+0x116/0x140 [ 28.185229] ? SyS_write+0x210/0x210 [ 28.188917] ? __do_page_fault+0x159/0xad0 [ 28.193215] ? do_syscall_64+0x4c/0x640 [ 28.197162] ? SyS_write+0x210/0x210 [ 28.200854] do_syscall_64+0x1d5/0x640 [ 28.204722] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 28.209894] RIP: 0033:0x444279 [ 28.213582] RSP: 002b:00007ffd05c32f08 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 [ 28.221269] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 0000000000444279 [ 28.228522] RDX: 000000000000006a RSI: 0000000020000000 RDI: 0000000000000003 [ 28.235767] RBP: 0000000000000000 R08: 00236f656469762f R09: 0000000000000001 [ 28.243027] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004034e0 [ 28.250272] R13: 0000000000000000 R14: 00007ffd05c32f30 R15: 00007ffd05c32f20 [ 28.257582] Kernel Offset: disabled [ 28.261191] Rebooting in 86400 seconds..