================================================================== BUG: KASAN: slab-use-after-free in mini_qdisc_pair_swap+0x68/0x190 net/sched/sch_generic.c:1568 Read of size 8 at addr ffff88803071c000 by task syz-executor/17475 CPU: 0 UID: 0 PID: 17475 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 mini_qdisc_pair_swap+0x68/0x190 net/sched/sch_generic.c:1568 tcf_chain_head_change_item net/sched/cls_api.c:522 [inline] tcf_chain0_head_change_cb_del+0x24c/0x380 net/sched/cls_api.c:969 tcf_block_put_ext+0x129/0x390 net/sched/cls_api.c:1559 clsact_destroy+0x25e/0x820 net/sched/sch_ingress.c:302 __qdisc_destroy+0x153/0x400 net/sched/sch_generic.c:1077 dev_shutdown+0x233/0x440 net/sched/sch_generic.c:1492 unregister_netdevice_many_notify+0x11b3/0x2340 net/core/dev.c:12371 unregister_netdevice_many net/core/dev.c:12446 [inline] unregister_netdevice_queue+0x317/0x350 net/core/dev.c:12260 unregister_netdevice include/linux/netdevice.h:3405 [inline] nsim_destroy+0x1e5/0x680 drivers/net/netdevsim/netdev.c:1180 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1528 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1540 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1763 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1778 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1282 [inline] device_release_driver_internal+0x46f/0x800 drivers/base/dd.c:1305 bus_remove_device+0x34d/0x440 drivers/base/bus.c:616 device_del+0x511/0x8e0 drivers/base/core.c:3878 device_unregister+0x21/0x100 drivers/base/core.c:3919 nsim_bus_dev_del drivers/net/netdevsim/bus.c:483 [inline] del_device_store+0x2aa/0x360 drivers/net/netdevsim/bus.c:244 kernfs_fop_write_iter+0x3af/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f917578e1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007ffc465f1da0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f917578e1ff RDX: 0000000000000001 RSI: 00007ffc465f1df0 RDI: 0000000000000005 RBP: 00007f91758152cb R08: 0000000000000000 R09: 00007ffc465f1bf7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffc465f1df0 R14: 00007f9176514620 R15: 0000000000000003 Allocated by task 17696: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_node_noprof+0x57a/0x820 mm/slub.c:5663 kmalloc_node_noprof include/linux/slab.h:987 [inline] qdisc_alloc+0x92/0x900 net/sched/sch_generic.c:951 qdisc_create_dflt+0x8e/0x4c0 net/sched/sch_generic.c:1008 mq_init+0x2dc/0x660 net/sched/sch_mq.c:90 qdisc_create_dflt+0x13b/0x4c0 net/sched/sch_generic.c:1015 attach_default_qdiscs net/sched/sch_generic.c:1197 [inline] dev_activate+0x1ce/0x1150 net/sched/sch_generic.c:1251 __dev_open+0x647/0x800 net/core/dev.c:1692 __dev_change_flags+0x1f7/0x680 net/core/dev.c:9736 netif_change_flags+0x88/0x1a0 net/core/dev.c:9799 dev_change_flags+0x130/0x260 net/core/dev_api.c:68 dev_ioctl+0x7b4/0x1150 net/core/dev_ioctl.c:842 sock_do_ioctl+0x22c/0x300 net/socket.c:1268 sock_ioctl+0x576/0x790 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x1c0/0x660 mm/slub.c:6876 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857 handle_softirqs+0x27d/0x850 kernel/softirq.c:622 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239 netdev_for_each_tx_queue include/linux/netdevice.h:2680 [inline] dev_shutdown+0x93/0x440 net/sched/sch_generic.c:1490 unregister_netdevice_many_notify+0x11b3/0x2340 net/core/dev.c:12371 unregister_netdevice_many net/core/dev.c:12446 [inline] unregister_netdevice_queue+0x317/0x350 net/core/dev.c:12260 unregister_netdevice include/linux/netdevice.h:3405 [inline] __tun_detach+0x6d9/0x15d0 drivers/net/tun.c:621 tun_detach drivers/net/tun.c:637 [inline] tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3436 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803071c000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of freed 2048-byte region [ffff88803071c000, ffff88803071c800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30718 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffa7000 ffffea0001f20c00 dead000000000002 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ffa7000 ffffea0001f20c00 dead000000000002 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000c1c601 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 129, tgid 129 (kworker/1:2), ts 22013558599, free_ts 17554298670 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] fw_create_instance+0x5c/0x180 drivers/base/firmware_loader/sysfs.c:408 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:155 [inline] firmware_fallback_sysfs+0x1e5/0xa40 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xfa4/0x1680 drivers/base/firmware_loader/main.c:898 request_firmware_work_func+0xaf/0x1c0 drivers/base/firmware_loader/main.c:1150 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 page last free pid 129 tgid 129 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 vfree+0x25a/0x400 mm/vmalloc.c:3466 delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3385 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff88803071bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803071bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88803071c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803071c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803071c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================