[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.24' (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 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: [ 29.515008] ================================================================== [ 29.522454] BUG: KASAN: use-after-free in __vb2_perform_fileio+0xce9/0xda0 [ 29.529442] Read of size 4 at addr ffff88809761e79c by task syz-executor204/8048 [ 29.536946] [ 29.538551] CPU: 0 PID: 8048 Comm: syz-executor204 Not tainted 4.14.294-syzkaller #0 [ 29.546402] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 [ 29.555824] Call Trace: [ 29.558390] dump_stack+0x1b2/0x281 [ 29.561992] print_address_description.cold+0x54/0x1d3 [ 29.567253] kasan_report_error.cold+0x8a/0x191 [ 29.571905] ? __vb2_perform_fileio+0xce9/0xda0 [ 29.576554] __asan_report_load4_noabort+0x68/0x70 [ 29.581463] ? __vb2_perform_fileio+0xce9/0xda0 [ 29.586109] __vb2_perform_fileio+0xce9/0xda0 [ 29.590583] ? __vb2_init_fileio+0xa90/0xa90 [ 29.594969] ? common_file_perm+0x3ee/0x580 [ 29.599271] vb2_fop_read+0x1ef/0x3d0 [ 29.603049] ? vb2_fop_write+0x3d0/0x3d0 [ 29.607087] v4l2_read+0x19a/0x200 [ 29.610606] do_iter_read+0x3eb/0x5b0 [ 29.614401] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 29.619046] vfs_readv+0xc8/0x120 [ 29.622477] ? compat_rw_copy_check_uvector+0x320/0x320 [ 29.627839] ? __do_page_fault+0x571/0xad0 [ 29.632079] ? lock_downgrade+0x740/0x740 [ 29.636207] SyS_preadv+0x15a/0x200 [ 29.639812] ? SyS_writev+0x30/0x30 [ 29.643419] ? __do_page_fault+0x159/0xad0 [ 29.647629] ? do_syscall_64+0x4c/0x640 [ 29.651583] ? SyS_writev+0x30/0x30 [ 29.655187] do_syscall_64+0x1d5/0x640 [ 29.659050] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.664210] RIP: 0033:0x7f629ae7b439 [ 29.667900] RSP: 002b:00007fff6216f058 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 [ 29.675578] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f629ae7b439 [ 29.682821] RDX: 0000000000000001 RSI: 0000000020000600 RDI: 0000000000000003 [ 29.690065] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 29.697309] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000007337 [ 29.704551] R13: 00007fff6216f06c R14: 00007fff6216f080 R15: 00007fff6216f070 [ 29.711802] [ 29.713407] Allocated by task 8048: [ 29.717014] kasan_kmalloc+0xeb/0x160 [ 29.720788] kmem_cache_alloc_trace+0x131/0x3d0 [ 29.725435] __vb2_init_fileio+0x17f/0xa90 [ 29.729650] __vb2_perform_fileio+0x993/0xda0 [ 29.734119] vb2_fop_read+0x1ef/0x3d0 [ 29.737895] v4l2_read+0x19a/0x200 [ 29.741418] do_iter_read+0x3eb/0x5b0 [ 29.745191] vfs_readv+0xc8/0x120 [ 29.748620] SyS_preadv+0x15a/0x200 [ 29.752220] do_syscall_64+0x1d5/0x640 [ 29.756081] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.761241] [ 29.762842] Freed by task 8051: [ 29.766093] kasan_slab_free+0xc3/0x1a0 [ 29.770041] kfree+0xc9/0x250 [ 29.773122] __vb2_cleanup_fileio+0xf5/0x150 [ 29.777506] vb2_core_queue_release+0x17/0x70 [ 29.781972] _vb2_fop_release+0x1c1/0x280 [ 29.786094] vivid_fop_release+0x17d/0x6c0 [ 29.790305] v4l2_release+0xf4/0x190 [ 29.793993] __fput+0x25f/0x7a0 [ 29.797244] task_work_run+0x11f/0x190 [ 29.801102] do_exit+0xa44/0x2850 [ 29.804530] do_group_exit+0x100/0x2e0 [ 29.808390] SyS_exit_group+0x19/0x20 [ 29.812172] do_syscall_64+0x1d5/0x640 [ 29.816035] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.821193] [ 29.822793] The buggy address belongs to the object at ffff88809761e480 [ 29.822793] which belongs to the cache kmalloc-1024 of size 1024 [ 29.835595] The buggy address is located 796 bytes inside of [ 29.835595] 1024-byte region [ffff88809761e480, ffff88809761e880) [ 29.847526] The buggy address belongs to the page: [ 29.852431] page:ffffea00025d8780 count:1 mapcount:0 mapping:ffff88809761e000 index:0x0 compound_mapcount: 0 [ 29.862376] flags: 0xfff00000008100(slab|head) [ 29.866932] raw: 00fff00000008100 ffff88809761e000 0000000000000000 0000000100000007 [ 29.874783] raw: ffffea000260c420 ffff88813fe64848 ffff88813fe74ac0 0000000000000000 [ 29.882631] page dumped because: kasan: bad access detected [ 29.888309] [ 29.889909] Memory state around the buggy address: [ 29.894809] ffff88809761e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.902140] ffff88809761e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.909475] >ffff88809761e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.916809] ^ [ 29.920928] ffff88809761e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.928257] ffff88809761e880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 29.935586] ================================================================== [ 29.942917] Disabling lock debugging due to kernel taint [ 29.948949] Kernel panic - not syncing: panic_on_warn set ... [ 29.948949] [ 29.956422] CPU: 0 PID: 8048 Comm: syz-executor204 Tainted: G B 4.14.294-syzkaller #0 [ 29.965502] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 [ 29.974839] Call Trace: [ 29.977414] dump_stack+0x1b2/0x281 [ 29.981017] panic+0x1f9/0x42d [ 29.984181] ? add_taint.cold+0x16/0x16 [ 29.988144] ? ___preempt_schedule+0x16/0x18 [ 29.992537] kasan_end_report+0x43/0x49 [ 29.996483] kasan_report_error.cold+0xa7/0x191 [ 30.001127] ? __vb2_perform_fileio+0xce9/0xda0 [ 30.005773] __asan_report_load4_noabort+0x68/0x70 [ 30.010677] ? __vb2_perform_fileio+0xce9/0xda0 [ 30.015339] __vb2_perform_fileio+0xce9/0xda0 [ 30.019820] ? __vb2_init_fileio+0xa90/0xa90 [ 30.024208] ? common_file_perm+0x3ee/0x580 [ 30.028514] vb2_fop_read+0x1ef/0x3d0 [ 30.032331] ? vb2_fop_write+0x3d0/0x3d0 [ 30.036366] v4l2_read+0x19a/0x200 [ 30.039884] do_iter_read+0x3eb/0x5b0 [ 30.043661] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 30.048314] vfs_readv+0xc8/0x120 [ 30.051745] ? compat_rw_copy_check_uvector+0x320/0x320 [ 30.057086] ? __do_page_fault+0x571/0xad0 [ 30.061298] ? lock_downgrade+0x740/0x740 [ 30.065441] SyS_preadv+0x15a/0x200 [ 30.069048] ? SyS_writev+0x30/0x30 [ 30.072700] ? __do_page_fault+0x159/0xad0 [ 30.076917] ? do_syscall_64+0x4c/0x640 [ 30.080870] ? SyS_writev+0x30/0x30 [ 30.084484] do_syscall_64+0x1d5/0x640 [ 30.088360] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.093537] RIP: 0033:0x7f629ae7b439 [ 30.097225] RSP: 002b:00007fff6216f058 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 [ 30.104920] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f629ae7b439 [ 30.112168] RDX: 0000000000000001 RSI: 0000000020000600 RDI: 0000000000000003 [ 30.119413] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 30.126671] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000007337 [ 30.134043] R13: 00007fff6216f06c R14: 00007fff6216f080 R15: 00007fff6216f070 [ 30.141474] Kernel Offset: disabled [ 30.145082] Rebooting in 86400 seconds..