Warning: Permanently added '10.128.1.36' (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 syzkaller login: [ 29.841266] ================================================================== [ 29.848818] BUG: KASAN: use-after-free in __vb2_perform_fileio+0xce9/0xda0 [ 29.855995] Read of size 4 at addr ffff888097e0d0dc by task syz-executor332/7972 [ 29.863699] [ 29.865309] CPU: 0 PID: 7972 Comm: syz-executor332 Not tainted 4.14.277-syzkaller #0 [ 29.873182] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.882513] Call Trace: [ 29.885117] dump_stack+0x1b2/0x281 [ 29.888750] print_address_description.cold+0x54/0x1d3 [ 29.894035] kasan_report_error.cold+0x8a/0x191 [ 29.898784] ? __vb2_perform_fileio+0xce9/0xda0 [ 29.903435] __asan_report_load4_noabort+0x68/0x70 [ 29.908429] ? __vb2_perform_fileio+0xce9/0xda0 [ 29.913093] __vb2_perform_fileio+0xce9/0xda0 [ 29.917569] ? __vb2_init_fileio+0xa90/0xa90 [ 29.921979] ? common_file_perm+0x3ee/0x580 [ 29.926288] vb2_fop_read+0x1ef/0x3d0 [ 29.930068] ? vb2_fop_write+0x3d0/0x3d0 [ 29.934144] v4l2_read+0x19a/0x200 [ 29.937664] do_iter_read+0x3eb/0x5b0 [ 29.941453] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 29.946100] vfs_readv+0xc8/0x120 [ 29.949532] ? compat_rw_copy_check_uvector+0x320/0x320 [ 29.954888] ? lock_downgrade+0x740/0x740 [ 29.959028] SyS_preadv+0x15a/0x200 [ 29.962644] ? SyS_writev+0x30/0x30 [ 29.966250] ? __do_page_fault+0x159/0xad0 [ 29.970475] ? do_syscall_64+0x4c/0x640 [ 29.974428] ? SyS_writev+0x30/0x30 [ 29.978054] do_syscall_64+0x1d5/0x640 [ 29.982016] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.987186] RIP: 0033:0x7f80103ac499 [ 29.990873] RSP: 002b:00007ffd5e031f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 [ 29.998568] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f80103ac499 [ 30.005990] RDX: 0000000000000004 RSI: 0000000020000600 RDI: 0000000000000003 [ 30.013242] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 30.020502] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000007471 [ 30.027754] R13: 00007ffd5e031f5c R14: 00007ffd5e031f70 R15: 00007ffd5e031f60 [ 30.035277] [ 30.036883] Allocated by task 7972: [ 30.040497] kasan_kmalloc+0xeb/0x160 [ 30.044304] kmem_cache_alloc_trace+0x131/0x3d0 [ 30.048957] __vb2_init_fileio+0x17f/0xa90 [ 30.053171] __vb2_perform_fileio+0x993/0xda0 [ 30.057827] vb2_fop_read+0x1ef/0x3d0 [ 30.061690] v4l2_read+0x19a/0x200 [ 30.065641] do_iter_read+0x3eb/0x5b0 [ 30.069424] vfs_readv+0xc8/0x120 [ 30.072853] SyS_preadv+0x15a/0x200 [ 30.076465] do_syscall_64+0x1d5/0x640 [ 30.080327] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.085490] [ 30.087091] Freed by task 7976: [ 30.090348] kasan_slab_free+0xc3/0x1a0 [ 30.094297] kfree+0xc9/0x250 [ 30.097380] __vb2_cleanup_fileio+0xf5/0x150 [ 30.101766] vb2_core_queue_release+0x17/0x70 [ 30.106243] _vb2_fop_release+0x1c1/0x280 [ 30.110373] vivid_fop_release+0x17d/0x6c0 [ 30.114585] v4l2_release+0xf4/0x190 [ 30.118273] __fput+0x25f/0x7a0 [ 30.121524] task_work_run+0x11f/0x190 [ 30.125396] do_exit+0xa44/0x2850 [ 30.128916] do_group_exit+0x100/0x2e0 [ 30.132776] SyS_exit_group+0x19/0x20 [ 30.136561] do_syscall_64+0x1d5/0x640 [ 30.140425] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.145590] [ 30.147197] The buggy address belongs to the object at ffff888097e0cdc0 [ 30.147197] which belongs to the cache kmalloc-1024 of size 1024 [ 30.160008] The buggy address is located 796 bytes inside of [ 30.160008] 1024-byte region [ffff888097e0cdc0, ffff888097e0d1c0) [ 30.171946] The buggy address belongs to the page: [ 30.176917] page:ffffea00025f8300 count:1 mapcount:0 mapping:ffff888097e0c040 index:0x0 compound_mapcount: 0 [ 30.187995] flags: 0xfff00000008100(slab|head) [ 30.192553] raw: 00fff00000008100 ffff888097e0c040 0000000000000000 0000000100000007 [ 30.200409] raw: ffffea00025d3aa0 ffffea00025d6120 ffff88813fe74ac0 0000000000000000 [ 30.208272] page dumped because: kasan: bad access detected [ 30.213960] [ 30.215562] Memory state around the buggy address: [ 30.220474] ffff888097e0cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.227813] ffff888097e0d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.235153] >ffff888097e0d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.242578] ^ [ 30.248790] ffff888097e0d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.256125] ffff888097e0d180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 30.263469] ================================================================== [ 30.270898] Disabling lock debugging due to kernel taint [ 30.278884] Kernel panic - not syncing: panic_on_warn set ... [ 30.278884] [ 30.286264] CPU: 1 PID: 7972 Comm: syz-executor332 Tainted: G B 4.14.277-syzkaller #0 [ 30.295348] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.304689] Call Trace: [ 30.307258] dump_stack+0x1b2/0x281 [ 30.310863] panic+0x1f9/0x42d [ 30.314029] ? add_taint.cold+0x16/0x16 [ 30.318161] ? ___preempt_schedule+0x16/0x18 [ 30.322551] kasan_end_report+0x43/0x49 [ 30.326497] kasan_report_error.cold+0xa7/0x191 [ 30.331141] ? __vb2_perform_fileio+0xce9/0xda0 [ 30.335790] __asan_report_load4_noabort+0x68/0x70 [ 30.340697] ? __vb2_perform_fileio+0xce9/0xda0 [ 30.345342] __vb2_perform_fileio+0xce9/0xda0 [ 30.349886] ? __vb2_init_fileio+0xa90/0xa90 [ 30.354386] ? common_file_perm+0x3ee/0x580 [ 30.358701] vb2_fop_read+0x1ef/0x3d0 [ 30.362484] ? vb2_fop_write+0x3d0/0x3d0 [ 30.366536] v4l2_read+0x19a/0x200 [ 30.370056] do_iter_read+0x3eb/0x5b0 [ 30.373833] ? finish_mkwrite_fault+0x5e0/0x5e0 [ 30.378483] vfs_readv+0xc8/0x120 [ 30.381914] ? compat_rw_copy_check_uvector+0x320/0x320 [ 30.387255] ? lock_downgrade+0x740/0x740 [ 30.391376] SyS_preadv+0x15a/0x200 [ 30.394977] ? SyS_writev+0x30/0x30 [ 30.398578] ? __do_page_fault+0x159/0xad0 [ 30.402875] ? do_syscall_64+0x4c/0x640 [ 30.406823] ? SyS_writev+0x30/0x30 [ 30.410441] do_syscall_64+0x1d5/0x640 [ 30.414313] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.419480] RIP: 0033:0x7f80103ac499 [ 30.423163] RSP: 002b:00007ffd5e031f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 [ 30.430849] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f80103ac499 [ 30.438104] RDX: 0000000000000004 RSI: 0000000020000600 RDI: 0000000000000003 [ 30.445437] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 30.452680] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000007471 [ 30.459924] R13: 00007ffd5e031f5c R14: 00007ffd5e031f70 R15: 00007ffd5e031f60 [ 30.467386] Kernel Offset: disabled [ 30.471000] Rebooting in 86400 seconds..