================================================================== 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 ffff88805a534900 by task v4l_id/4472 CPU: 1 PID: 4472 Comm: v4l_id Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 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+0x597/0x670 fs/char_dev.c:414 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3750 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 do_sys_openat2+0x142/0x4a0 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+0x135/0x160 fs/open.c:1280 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: 0033:0x7fdb2f89c407 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:00007fffc7e2da30 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fdb2f7ae880 RCX: 00007fdb2f89c407 RDX: 0000000000000000 RSI: 00007fffc7e2ef1d RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fffc7e2dc80 R14: 00007fdb3002a000 R15: 000055d961a284d8 The buggy address belongs to the page: page:ffffea0001694d00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a534 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001613108 ffffea000167a208 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 154, ts 91959334744, free_ts 91959341918 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 stack_depot_save+0x342/0x440 lib/stackdepot.c:302 kasan_save_stack+0x4b/0x60 mm/kasan/common.c:40 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x10a/0x7c0 kernel/rcu/tree.c:3600 __hw_addr_del_entry net/core/dev_addr_lists.c:145 [inline] __hw_addr_del_ex+0x521/0x620 net/core/dev_addr_lists.c:194 __hw_addr_unsync_one+0x59/0x270 net/core/dev_addr_lists.c:230 __hw_addr_unsync net/core/dev_addr_lists.c:290 [inline] dev_mc_unsync+0x1a6/0x2d0 net/core/dev_addr_lists.c:984 vlan_dev_stop+0x49/0x230 net/8021q/vlan_dev.c:298 __dev_close_many+0x1c1/0x2a0 net/core/dev.c:1621 dev_close_many+0x21f/0x400 net/core/dev.c:1646 unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110 default_device_exit_batch+0x336/0x390 net/core/dev.c:11667 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635 process_one_work+0x863/0x1000 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+0x94/0x280 mm/page_alloc.c:3396 stack_depot_save+0x418/0x440 lib/stackdepot.c:335 kasan_save_stack+0x4b/0x60 mm/kasan/common.c:40 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x10a/0x7c0 kernel/rcu/tree.c:3600 __hw_addr_del_entry net/core/dev_addr_lists.c:145 [inline] __hw_addr_del_ex+0x521/0x620 net/core/dev_addr_lists.c:194 __hw_addr_unsync_one+0x59/0x270 net/core/dev_addr_lists.c:230 __hw_addr_unsync net/core/dev_addr_lists.c:290 [inline] dev_mc_unsync+0x1a6/0x2d0 net/core/dev_addr_lists.c:984 vlan_dev_stop+0x49/0x230 net/8021q/vlan_dev.c:298 __dev_close_many+0x1c1/0x2a0 net/core/dev.c:1621 dev_close_many+0x21f/0x400 net/core/dev.c:1646 unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110 default_device_exit_batch+0x336/0x390 net/core/dev.c:11667 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 Memory state around the buggy address: ffff88805a534800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a534880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a534900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a534980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a534a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================