================================================================== BUG: KASAN: use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] BUG: KASAN: use-after-free in v4l2_fh_open+0xc6/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff88804e014900 by task v4l_id/5659 CPU: 1 PID: 5659 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+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xc6/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x152/0x990 drivers/media/usb/em28xx/em28xx-video.c:2163 v4l2_open+0x20b/0x360 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x5c5/0x6a0 fs/char_dev.c:414 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa44b4ec407 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:00007ffdc4ee8bf0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa44b3fe880 RCX: 00007fa44b4ec407 RDX: 0000000000000000 RSI: 00007ffdc4ee9f1d RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffdc4ee8e40 R14: 00007fa44bc7a000 R15: 000055d9aa1d54d8 The buggy address belongs to the page: page:ffffea0001380500 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4e014 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001d79908 ffff8880b90409f0 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x102800(GFP_NOWAIT|__GFP_NOWARN|__GFP_HARDWALL), pid 4444, ts 96607947258, free_ts 96607952064 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 stack_depot_save+0x342/0x440 lib/stackdepot.c:302 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track+0x62/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 uevent_net_broadcast_untagged lib/kobject_uevent.c:337 [inline] kobject_uevent_net_broadcast+0x40d/0x530 lib/kobject_uevent.c:409 kobject_uevent_env+0x556/0x890 lib/kobject_uevent.c:608 device_add+0x91c/0xfb0 drivers/base/core.c:3393 input_register_device+0xa5b/0x1140 drivers/input/input.c:2412 em28xx_register_snapshot_button+0x2d8/0x460 drivers/media/usb/em28xx/em28xx-input.c:610 em28xx_init_buttons drivers/media/usb/em28xx/em28xx-input.c:648 [inline] em28xx_ir_init+0x625/0x1db0 drivers/media/usb/em28xx/em28xx-input.c:715 em28xx_init_extension+0x118/0x1b0 drivers/media/usb/em28xx/em28xx-core.c:1126 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 stack_depot_save+0x418/0x440 lib/stackdepot.c:335 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track+0x62/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 uevent_net_broadcast_untagged lib/kobject_uevent.c:337 [inline] kobject_uevent_net_broadcast+0x40d/0x530 lib/kobject_uevent.c:409 kobject_uevent_env+0x556/0x890 lib/kobject_uevent.c:608 device_add+0x91c/0xfb0 drivers/base/core.c:3393 input_register_device+0xa5b/0x1140 drivers/input/input.c:2412 em28xx_register_snapshot_button+0x2d8/0x460 drivers/media/usb/em28xx/em28xx-input.c:610 em28xx_init_buttons drivers/media/usb/em28xx/em28xx-input.c:648 [inline] em28xx_ir_init+0x625/0x1db0 drivers/media/usb/em28xx/em28xx-input.c:715 em28xx_init_extension+0x118/0x1b0 drivers/media/usb/em28xx/em28xx-core.c:1126 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 Memory state around the buggy address: ffff88804e014800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804e014880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88804e014900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88804e014980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804e014a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================