================================================================== BUG: KASAN: slab-use-after-free in dummy_queue+0x937/0xb00 drivers/usb/gadget/udc/dummy_hcd.c:749 Read of size 1 at addr ffff888056ed48e8 by task syz.0.146/6451 CPU: 0 UID: 0 PID: 6451 Comm: syz.0.146 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 dummy_queue+0x937/0xb00 drivers/usb/gadget/udc/dummy_hcd.c:749 usb_ep_queue+0xfa/0x3c0 drivers/usb/gadget/udc/core.c:305 raw_process_ep_io+0x64d/0xc40 drivers/usb/gadget/legacy/raw_gadget.c:1114 raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1153 [inline] raw_ioctl+0x25a/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd29419ddeb Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fd294fa3f60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fd29419ddeb RDX: 00007fd294fa3fe0 RSI: 0000000040085507 RDI: 0000000000000004 RBP: 0000000000000004 R08: 00007fd294550320 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000200000000040 R13: 0000000000000000 R14: 00007fd294425fa0 R15: 00007fff6284a568 Allocated by task 6035: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_noprof+0x32f/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] usb_copy_descriptors+0xcd/0x320 drivers/usb/gadget/config.c:82 f_midi2_bind+0x1dad/0x2770 drivers/usb/gadget/function/f_midi2.c:2026 usb_add_function+0x219/0x890 drivers/usb/gadget/composite.c:333 configfs_composite_bind+0xd83/0x1960 drivers/usb/gadget/configfs.c:1802 gadget_bind_driver+0x28c/0xbf0 drivers/usb/gadget/udc/core.c:1662 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763 driver_register+0x1e2/0x360 drivers/base/driver.c:174 usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1752 gadget_dev_desc_UDC_store+0x1b0/0x2e0 drivers/usb/gadget/configfs.c:300 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6338: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x22b/0x6d0 mm/slub.c:6792 usb_free_descriptors include/linux/usb/gadget.h:903 [inline] usb_free_all_descriptors+0x81/0x1a0 drivers/usb/gadget/config.c:151 purge_configs_funcs+0x285/0x510 drivers/usb/gadget/configfs.c:1600 configfs_composite_unbind+0xae/0x210 drivers/usb/gadget/configfs.c:1846 gadget_unbind_driver+0x20c/0x4f0 drivers/usb/gadget/udc/core.c:1724 device_remove+0xcb/0x180 drivers/base/dd.c:616 __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372 driver_detach+0xd8/0x1b0 drivers/base/dd.c:1435 bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:832 driver_unregister+0x76/0xb0 drivers/base/driver.c:202 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1784 unregister_gadget drivers/usb/gadget/configfs.c:263 [inline] gadget_dev_desc_UDC_store+0x170/0x2e0 drivers/usb/gadget/configfs.c:290 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888056ed4800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 232 bytes inside of freed 512-byte region [ffff888056ed4800, ffff888056ed4a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56ed4 head: order:2 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 ffff88801c02ec80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801c02ec80 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 64, tgid 64 (kworker/u8:4), ts 67553029135 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab mm/slub.c:3462 [inline] new_slab+0xa9/0x6e0 mm/slub.c:3513 refill_objects+0xe3/0x410 mm/slub.c:7410 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x67c/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0xad0 net/ipv6/route.c:3833 ip6_route_add+0x4b/0x1d0 net/ipv6/route.c:3962 addrconf_add_mroute+0x1de/0x350 net/ipv6/addrconf.c:2568 addrconf_add_dev+0x14e/0x1a0 net/ipv6/addrconf.c:2586 addrconf_dev_config net/ipv6/addrconf.c:3508 [inline] addrconf_init_auto_addrs+0x10e/0x780 net/ipv6/addrconf.c:3596 addrconf_notify+0xa10/0x1ba0 net/ipv6/addrconf.c:3776 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2275 page last free pid 1 tgid 1 ts 15155800664 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] free_pages_prepare+0x586/0xe00 mm/page_alloc.c:1463 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:7072 debug_vm_pgtable_free_huge_page mm/debug_vm_pgtable.c:980 [inline] destroy_args+0xa8/0x7a0 mm/debug_vm_pgtable.c:993 debug_vm_pgtable+0x1d69/0x3490 mm/debug_vm_pgtable.c:1368 do_one_initcall+0x11c/0x6f0 init/main.c:1357 do_initcall_level init/main.c:1419 [inline] do_initcalls init/main.c:1435 [inline] do_basic_setup init/main.c:1455 [inline] kernel_init_freeable+0x6ea/0x7b0 init/main.c:1670 kernel_init+0x21/0x1e0 init/main.c:1560 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888056ed4780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888056ed4800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888056ed4880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888056ed4900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888056ed4980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================