================================================================== BUG: KASAN: use-after-free in v4l2_open+0x32d/0x340 drivers/media/v4l2-core/v4l2-dev.c:432 Read of size 4 at addr ffff8880607c89b0 by task v4l_id/10519 CPU: 1 PID: 10519 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: 0033:0x7fa23fc70407 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:00007ffe9db4dbf0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa23fb82880 RCX: 00007fa23fc70407 RDX: 0000000000000000 RSI: 00007ffe9db4ef1b RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffe9db4de40 R14: 00007fa2403fe000 R15: 000056330d7e24d8 The buggy address belongs to the page: page:ffffea000181f200 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x607c8 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea00010d9a08 ffffea0001805b08 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 4911, ts 649857465953, free_ts 649857478232 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+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+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 kernfs_put+0x311/0x480 fs/kernfs/dir.c:547 kernfs_remove_by_name_ns+0x99/0x100 fs/kernfs/dir.c:1567 device_remove_sys_dev_entry drivers/base/core.c:3250 [inline] device_del+0x3de/0xa80 drivers/base/core.c:3597 cdev_device_del+0x23/0xf0 fs/char_dev.c:573 put_i2c_dev drivers/i2c/i2c-dev.c:94 [inline] i2cdev_detach_adapter+0x217/0x280 drivers/i2c/i2c-dev.c:702 i2cdev_notifier_call+0x36/0x50 drivers/i2c/i2c-dev.c:717 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 device_del+0x29c/0xa80 drivers/base/core.c:3589 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+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+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 kernfs_put+0x311/0x480 fs/kernfs/dir.c:547 kernfs_remove_by_name_ns+0x99/0x100 fs/kernfs/dir.c:1567 device_remove_sys_dev_entry drivers/base/core.c:3250 [inline] device_del+0x3de/0xa80 drivers/base/core.c:3597 cdev_device_del+0x23/0xf0 fs/char_dev.c:573 put_i2c_dev drivers/i2c/i2c-dev.c:94 [inline] i2cdev_detach_adapter+0x217/0x280 drivers/i2c/i2c-dev.c:702 i2cdev_notifier_call+0x36/0x50 drivers/i2c/i2c-dev.c:717 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 device_del+0x29c/0xa80 drivers/base/core.c:3589 Memory state around the buggy address: ffff8880607c8880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880607c8900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880607c8980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880607c8a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880607c8a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================