================================================================== 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 ffff8880536b0900 by task v4l_id/7348 CPU: 1 PID: 7348 Comm: v4l_id Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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: 0033:0x7f497fa78407 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:00007fff2a43c060 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f497f98a880 RCX: 00007f497fa78407 RDX: 0000000000000000 RSI: 00007fff2a43df1c RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fff2a43c2b0 R14: 00007f4980206000 R15: 00005643ec5e54d8 The buggy address belongs to the page: page:ffffea00014dac00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x536b0 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea00014db208 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 7, ts 238817531110, free_ts 238817535605 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:5501 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] kfree+0xef/0x2a0 mm/slub.c:4564 devtmpfs_submit_req drivers/base/devtmpfs.c:112 [inline] devtmpfs_create_node+0x207/0x290 drivers/base/devtmpfs.c:141 device_add+0xcd1/0xfb0 drivers/base/core.c:3383 cdev_device_add+0x1a4/0x340 fs/char_dev.c:549 evdev_connect+0x34b/0x3f0 drivers/input/evdev.c:1386 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xda7/0x1140 drivers/input/input.c:2429 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 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] kfree+0xef/0x2a0 mm/slub.c:4564 devtmpfs_submit_req drivers/base/devtmpfs.c:112 [inline] devtmpfs_create_node+0x207/0x290 drivers/base/devtmpfs.c:141 device_add+0xcd1/0xfb0 drivers/base/core.c:3383 cdev_device_add+0x1a4/0x340 fs/char_dev.c:549 evdev_connect+0x34b/0x3f0 drivers/input/evdev.c:1386 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xda7/0x1140 drivers/input/input.c:2429 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 Memory state around the buggy address: ffff8880536b0800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880536b0880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880536b0900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880536b0980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880536b0a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================