================================================================== 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+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff888061ae8900 by task v4l_id/5250 CPU: 1 PID: 5250 Comm: v4l_id Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x15d/0xa10 drivers/media/usb/em28xx/em28xx-video.c:2163 v4l2_open+0x228/0x360 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x54a/0x630 fs/char_dev.c:414 do_dentry_open+0x807/0xfb0 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2705/0x2f20 fs/namei.c:3742 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fba9914d9a4 Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007fff3f071d00 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fff3f071f18 RCX: 00007fba9914d9a4 RDX: 0000000000000000 RSI: 00007fff3f073f1b RDI: 00000000ffffff9c RBP: 00007fff3f073f1b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff3f071f30 R14: 000055adcf532670 R15: 00007fba99596a80 The buggy address belongs to the page: page:ffffea000186ba00 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x2 pfn:0x61ae8 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea00015e2d08 ffffea00009a5908 0000000000000000 raw: 0000000000000002 0000000000000002 00000000ffffff7f 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 4248, ts 133407869759, free_ts 133407876095 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192 __alloc_pages+0x272/0x700 mm/page_alloc.c:5466 stack_depot_save+0x319/0x440 lib/stackdepot.c:302 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track+0x62/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 kernfs_put+0x325/0x4a0 fs/kernfs/dir.c:547 kernfs_remove_by_name_ns+0x99/0x100 fs/kernfs/dir.c:1567 media_device_unregister+0x35f/0x3f0 drivers/media/mc/mc-device.c:846 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3464 [inline] em28xx_release_resources+0xa6/0x230 drivers/media/usb/em28xx/em28xx-cards.c:3485 em28xx_usb_disconnect+0x1c4/0x520 drivers/media/usb/em28xx/em28xx-cards.c:4154 usb_unbind_interface+0x1cd/0x840 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1229 [inline] device_release_driver_internal+0x50e/0x7f0 drivers/base/dd.c:1262 bus_remove_device+0x2e5/0x400 drivers/base/bus.c:531 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+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 stack_depot_save+0x3ef/0x440 lib/stackdepot.c:335 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track+0x62/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 kernfs_put+0x325/0x4a0 fs/kernfs/dir.c:547 kernfs_remove_by_name_ns+0x99/0x100 fs/kernfs/dir.c:1567 media_device_unregister+0x35f/0x3f0 drivers/media/mc/mc-device.c:846 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3464 [inline] em28xx_release_resources+0xa6/0x230 drivers/media/usb/em28xx/em28xx-cards.c:3485 em28xx_usb_disconnect+0x1c4/0x520 drivers/media/usb/em28xx/em28xx-cards.c:4154 usb_unbind_interface+0x1cd/0x840 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1229 [inline] device_release_driver_internal+0x50e/0x7f0 drivers/base/dd.c:1262 bus_remove_device+0x2e5/0x400 drivers/base/bus.c:531 Memory state around the buggy address: ffff888061ae8800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888061ae8880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888061ae8900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888061ae8980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888061ae8a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================