================================================================== BUG: KASAN: slab-use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] BUG: KASAN: slab-use-after-free in v4l2_fh_open+0xca/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff88807b150738 by task v4l_id/11279 CPU: 1 PID: 11279 Comm: v4l_id Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xca/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x157/0x980 drivers/media/usb/em28xx/em28xx-video.c:2153 v4l2_open+0x212/0x360 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x5cc/0x6a0 fs/char_dev.c:414 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x27f1/0x3230 fs/namei.c:3797 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1c6f0a7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd31830bf0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f1c6f78a880 RCX: 00007f1c6f0a7407 RDX: 0000000000000000 RSI: 00007ffd31832f1b RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffd31830e40 R14: 00007f1c6f887000 R15: 000055bcecb4e4d8 Allocated by task 8: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] em28xx_v4l2_init+0x10b/0x2e70 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x11c/0x1b0 drivers/media/usb/em28xx/em28xx-core.c:1116 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 8: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x1670/0x2e70 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x11c/0x1b0 drivers/media/usb/em28xx/em28xx-core.c:1116 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 insert_work+0x3d/0x310 kernel/workqueue.c:1651 __queue_work+0xc39/0x1020 kernel/workqueue.c:1800 queue_work_on+0x128/0x1f0 kernel/workqueue.c:1835 queue_work include/linux/workqueue.h:562 [inline] schedule_work include/linux/workqueue.h:623 [inline] f2fs_handle_critical_error+0x58e/0x900 fs/f2fs/super.c:4117 f2fs_write_end_io+0x52e/0x8b0 fs/f2fs/data.c:353 __submit_merged_bio+0x256/0x630 fs/f2fs/data.c:539 __f2fs_submit_merged_write fs/f2fs/data.c:632 [inline] __submit_merged_write_cond+0x252/0x520 fs/f2fs/data.c:654 f2fs_submit_merged_write_cond fs/f2fs/data.c:671 [inline] f2fs_write_cache_pages fs/f2fs/data.c:3201 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3301 [inline] f2fs_write_data_pages+0x2d72/0x3840 fs/f2fs/data.c:3330 do_writepages+0x3b3/0x630 mm/page-writeback.c:2575 filemap_fdatawrite_wbc+0x122/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_fdatawrite+0xec/0x150 mm/filemap.c:434 f2fs_sync_dirty_inodes+0x307/0x800 fs/f2fs/checkpoint.c:1107 block_operations fs/f2fs/checkpoint.c:1245 [inline] f2fs_write_checkpoint+0xba6/0x1fd0 fs/f2fs/checkpoint.c:1640 kill_f2fs_super+0x263/0x3d0 fs/f2fs/super.c:4850 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807b150000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1848 bytes inside of freed 8192-byte region [ffff88807b150000, ffff88807b152000) The buggy address belongs to the physical page: page:ffffea0001ec5400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7b150 head:ffffea0001ec5400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c42280 ffffea000178e200 dead000000000002 raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5422, tgid 5422 (rcS), ts 54044375050, free_ts 53896120827 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3191 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0x1114/0x1f50 security/tomoyo/audit.c:264 tomoyo_supervisor+0x363/0x1170 security/tomoyo/common.c:2089 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x152/0x1f0 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0x1592/0x1a60 security/tomoyo/domain.c:881 tomoyo_bprm_check_security+0x116/0x170 security/tomoyo/tomoyo.c:101 security_bprm_check+0x62/0xa0 security/security.c:1103 search_binary_handler fs/exec.c:1763 [inline] exec_binprm fs/exec.c:1817 [inline] bprm_execve+0xa6e/0x1700 fs/exec.c:1892 do_execveat_common+0x51b/0x6c0 fs/exec.c:1998 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35a/0x400 mm/slub.c:3736 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 ptlock_alloc mm/memory.c:6177 [inline] ptlock_init include/linux/mm.h:2964 [inline] pmd_ptlock_init include/linux/mm.h:3064 [inline] pagetable_pmd_ctor include/linux/mm.h:3102 [inline] pmd_alloc_one include/asm-generic/pgalloc.h:137 [inline] __pmd_alloc+0x111/0x8b0 mm/memory.c:5599 pmd_alloc include/linux/mm.h:2863 [inline] alloc_new_pmd mm/mremap.c:96 [inline] move_page_tables+0x17a9/0x1980 mm/mremap.c:555 shift_arg_pages fs/exec.c:713 [inline] setup_arg_pages+0xae6/0x1010 fs/exec.c:836 load_elf_binary+0xb9e/0x2860 fs/binfmt_elf.c:1045 search_binary_handler fs/exec.c:1775 [inline] exec_binprm fs/exec.c:1817 [inline] bprm_execve+0xb08/0x1700 fs/exec.c:1892 do_execveat_common+0x51b/0x6c0 fs/exec.c:1998 do_execve fs/exec.c:2072 [inline] __do_sys_execve fs/exec.c:2148 [inline] __se_sys_execve fs/exec.c:2143 [inline] __x64_sys_execve+0x92/0xa0 fs/exec.c:2143 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff88807b150600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b150680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807b150700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807b150780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b150800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================