================================================================== BUG: KASAN: use-after-free in v4l2_open+0x32d/0x340 drivers/media/v4l2-core/v4l2-dev.c:432 Read of size 4 at addr ffff88807ac809b0 by task v4l_id/7624 CPU: 1 PID: 7624 Comm: v4l_id Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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_open+0x32d/0x340 drivers/media/v4l2-core/v4l2-dev.c:432 chrdev_open+0x585/0x5f0 fs/char_dev.c:414 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 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: 0033:0x7faa3a92a407 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:00007fffcf91a020 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007faa3a83c880 RCX: 00007faa3a92a407 RDX: 0000000000000000 RSI: 00007fffcf91bf1c RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fffcf91a270 R14: 00007faa3b0b8000 R15: 0000555a2f50b4d8 The buggy address belongs to the page: page:ffffea0001eb2000 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x2 pfn:0x7ac80 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffff88813fffb910 ffff88813fffb910 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 0x102cc0(GFP_USER|__GFP_NOWARN), pid 7, ts 257631441534, free_ts 257631447088 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 stack_depot_save+0x356/0x460 lib/stackdepot.c:302 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0xa9/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 kmem_cache_zalloc include/linux/slab.h:728 [inline] __kernfs_new_node+0xe3/0x6b0 fs/kernfs/dir.c:593 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:669 kernfs_create_dir_ns+0x40/0x120 fs/kernfs/dir.c:1005 sysfs_create_dir_ns+0x12c/0x290 fs/sysfs/dir.c:59 create_dir lib/kobject.c:89 [inline] kobject_add_internal+0x5ba/0xcd0 lib/kobject.c:263 kobject_add_varg lib/kobject.c:398 [inline] kobject_add+0x160/0x230 lib/kobject.c:450 device_add+0x470/0x1050 drivers/base/core.c:3347 cdev_device_add+0x19d/0x340 fs/char_dev.c:549 evdev_connect+0x350/0x3f0 drivers/input/evdev.c:1386 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xd26/0x10c0 drivers/input/input.c:2429 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+0x42f/0x460 lib/stackdepot.c:335 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0xa9/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 kmem_cache_zalloc include/linux/slab.h:728 [inline] __kernfs_new_node+0xe3/0x6b0 fs/kernfs/dir.c:593 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:669 kernfs_create_dir_ns+0x40/0x120 fs/kernfs/dir.c:1005 sysfs_create_dir_ns+0x12c/0x290 fs/sysfs/dir.c:59 create_dir lib/kobject.c:89 [inline] kobject_add_internal+0x5ba/0xcd0 lib/kobject.c:263 kobject_add_varg lib/kobject.c:398 [inline] kobject_add+0x160/0x230 lib/kobject.c:450 device_add+0x470/0x1050 drivers/base/core.c:3347 cdev_device_add+0x19d/0x340 fs/char_dev.c:549 evdev_connect+0x350/0x3f0 drivers/input/evdev.c:1386 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xd26/0x10c0 drivers/input/input.c:2429 Memory state around the buggy address: ffff88807ac80880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807ac80900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88807ac80980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807ac80a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807ac80a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================