==================================================================
BUG: KASAN: slab-use-after-free in find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1650
Read of size 1 at addr ffff88801dfb44e8 by task syz-executor/5617

CPU: 0 UID: 0 PID: 5617 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
 <IRQ>
 __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
 find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1650
 dummy_timer+0x506/0x3840 drivers/usb/gadget/udc/dummy_hcd.c:1922
 __run_hrtimer kernel/time/hrtimer.c:2079 [inline]
 __hrtimer_run_queues+0x448/0x9a0 kernel/time/hrtimer.c:2136
 hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2153
 handle_softirqs+0x216/0xa20 kernel/softirq.c:669
 __do_softirq kernel/softirq.c:703 [inline]
 invoke_softirq kernel/softirq.c:542 [inline]
 __irq_exit_rcu+0x178/0x220 kernel/softirq.c:786
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:809
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:389 [inline]
RIP: 0010:__rcu_read_lock+0x17/0x70 kernel/rcu/tree_plugin.h:412
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 53 65 48 8b 1d 91 ec c8 13 <48> 8d bb c4 04 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83
RSP: 0018:ffffc90003dff528 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff88803513a580 RCX: ffffc90003dff4fc
RDX: 1ffff920007bfebc RSI: ffffffff8288be34 RDI: ffffc90003dff5a8
RBP: ffffc90003dff5f0 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 00000000000188bd R12: ffffffff81f829c0
R13: ffffc90003dff5a8 R14: 0000000000000000 R15: ffff88803513a580
 rcu_read_lock include/linux/rcupdate.h:847 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0xae/0x2090 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 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:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6923
 vfree mm/vmalloc.c:3549 [inline]
 vfree+0x12a/0x850 mm/vmalloc.c:3521
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:885 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1042 [inline]
 do_ip6t_get_ctl+0xa0b/0xc30 net/ipv6/netfilter/ip6_tables.c:1683
 nf_getsockopt+0x7c/0xe0 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x207/0x2a0 net/ipv6/ipv6_sockglue.c:1371
 tcp_getsockopt+0xa1/0x110 net/ipv4/tcp.c:4881
 do_sock_getsockopt+0x415/0x570 net/socket.c:2505
 __sys_getsockopt+0x148/0x260 net/socket.c:2536
 __do_sys_getsockopt net/socket.c:2543 [inline]
 __se_sys_getsockopt net/socket.c:2540 [inline]
 __x64_sys_getsockopt+0xbd/0x160 net/socket.c:2540
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x7b0 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f82117a12ea
Code: 48 83 ec 10 89 d2 48 63 ff 45 31 c9 6a 2a 45 31 c0 31 c9 e8 d8 99 fb ff 48 83 c4 18 c3 0f 1f 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7
RSP: 002b:00007fff9ddda488 EFLAGS: 00000216 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007fff9ddda510 RCX: 00007f82117a12ea
RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fff9ddda4ac R09: 0000000000000000
R10: 00007fff9ddda510 R11: 0000000000000216 R12: 00007f82119f64c0
R13: 00007fff9ddda4ac R14: 0000000000000000 R15: 00007f82119f7fc0
 </TASK>

Allocated by task 6534:
 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:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5531 [inline]
 __kmalloc_noprof+0x32f/0x840 mm/slub.c:5556
 _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:2025
 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:1663
 call_driver_probe drivers/base/dd.c:629 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:707
 __driver_probe_device+0x210/0x460 drivers/base/dd.c:869
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:899
 __driver_attach+0x231/0x5b0 drivers/base/dd.c:1300
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
 bus_add_driver+0x4bf/0x620 drivers/base/bus.c:782
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1753
 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/0x1040 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+0x123/0x7b0 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 8188:
 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:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6923
 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:1725
 device_remove+0xcb/0x180 drivers/base/dd.c:617
 __device_release_driver drivers/base/dd.c:1357 [inline]
 device_release_driver_internal+0x441/0x610 drivers/base/dd.c:1380
 driver_detach+0xd8/0x1b0 drivers/base/dd.c:1443
 bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:851
 driver_unregister+0x76/0xb0 drivers/base/driver.c:202
 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1785
 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/0x1040 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+0x123/0x7b0 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801dfb4400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 232 bytes inside of
 freed 512-byte region [ffff88801dfb4400, ffff88801dfb4600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1dfb4
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 ffff88813ff10c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff10c80 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 1, tgid 1 (swapper/0), ts 2862422954
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x112f/0x3640 mm/page_alloc.c:3940
 __alloc_frozen_pages_noprof+0x2ad/0x31e0 mm/page_alloc.c:5464
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab mm/slub.c:3499 [inline]
 new_slab+0xb1/0x6d0 mm/slub.c:3550
 refill_objects+0xe3/0x410 mm/slub.c:7539
 refill_sheaf mm/slub.c:2917 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
 alloc_from_pcs mm/slub.c:4887 [inline]
 slab_alloc_node mm/slub.c:5021 [inline]
 __kmalloc_cache_noprof+0x4ef/0x6d0 mm/slub.c:5676
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 device_private_init drivers/base/core.c:3608 [inline]
 device_add+0xd3f/0x1970 drivers/base/core.c:3659
 tty_register_device_attr+0x388/0x810 drivers/tty/tty_io.c:3254
 tty_register_device drivers/tty/tty_io.c:3189 [inline]
 tty_register_driver+0x769/0xb50 drivers/tty/tty_io.c:3469
 vty_init+0x32c/0x370 drivers/tty/vt/vt.c:4095
 tty_init+0x1a3/0x1b0 drivers/tty/tty_io.c:3664
 chr_dev_init+0x12a/0x140 mm/char-mem.c:784
 do_one_initcall+0x11c/0x6f0 init/main.c:1419
 do_initcall_level init/main.c:1481 [inline]
 do_initcalls init/main.c:1497 [inline]
 do_basic_setup init/main.c:1517 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1732
 kernel_init+0x21/0x1e0 init/main.c:1622
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88801dfb4380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801dfb4400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801dfb4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88801dfb4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801dfb4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 90 90 90 90 90    	add    %dl,-0x6f6f6f70(%rax)
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	f3 0f 1e fa          	endbr64
  17:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1e:	fc ff df
  21:	53                   	push   %rbx
  22:	65 48 8b 1d 91 ec c8 	mov    %gs:0x13c8ec91(%rip),%rbx        # 0x13c8ecbb
  29:	13
* 2a:	48 8d bb c4 04 00 00 	lea    0x4c4(%rbx),%rdi <-- trapping instruction
  31:	48 89 fa             	mov    %rdi,%rdx
  34:	48 c1 ea 03          	shr    $0x3,%rdx
  38:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
  3c:	48 89 f8             	mov    %rdi,%rax
  3f:	83                   	.byte 0x83