================================================================== BUG: KASAN: use-after-free in netdev_need_ops_lock include/net/netdev_lock.h:33 [inline] BUG: KASAN: use-after-free in netdev_unlock_ops include/net/netdev_lock.h:47 [inline] BUG: KASAN: use-after-free in __linkwatch_run_queue+0x5d6/0x7e0 net/core/link_watch.c:245 Read of size 8 at addr ffff888027aac008 by task kworker/u8:9/5997 CPU: 0 UID: 0 PID: 5997 Comm: kworker/u8:9 Not tainted 6.15.0-rc7-syzkaller-00112-geccf6f2f6ab9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound linkwatch_event Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xb4/0x290 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 netdev_need_ops_lock include/net/netdev_lock.h:33 [inline] netdev_unlock_ops include/net/netdev_lock.h:47 [inline] __linkwatch_run_queue+0x5d6/0x7e0 net/core/link_watch.c:245 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888027aac340 pfn:0x27aac flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001f5e708 ffff8880b883f600 0000000000000000 raw: ffff888027aac340 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 0x446dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 7139, tgid 7138 (syz.1.353), ts 191370321400, free_ts 192256516057 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966 __alloc_pages_noprof+0xa/0x30 mm/page_alloc.c:5000 __alloc_pages_node_noprof include/linux/gfp.h:284 [inline] alloc_pages_node_noprof include/linux/gfp.h:311 [inline] ___kmalloc_large_node+0x85/0x200 mm/slub.c:4271 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4299 __do_kmalloc_node mm/slub.c:4315 [inline] __kvmalloc_node_noprof+0x74/0x5e0 mm/slub.c:5012 alloc_netdev_mqs+0xa6/0x11e0 net/core/dev.c:11606 tun_set_iff+0x532/0xef0 drivers/net/tun.c:2752 __tun_chr_ioctl+0x788/0x1d90 drivers/net/tun.c:3048 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 7138 tgid 7138 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1258 [inline] __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2721 __folio_put+0x21b/0x2c0 mm/swap.c:112 folio_put include/linux/mm.h:1580 [inline] free_large_kmalloc+0x145/0x200 mm/slub.c:4767 device_release+0x99/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11307 tun_detach drivers/net/tun.c:639 [inline] tun_chr_close+0x13c/0x1c0 drivers/net/tun.c:3390 __fput+0x449/0xa70 fs/file_table.c:465 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888027aabf00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027aabf80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc >ffff888027aac000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888027aac080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888027aac100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================