==================================================================
BUG: KASAN: slab-use-after-free in find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1622
Read of size 1 at addr ffff8880794e4512 by task syz.0.5543/32718

CPU: 0 UID: 0 PID: 32718 Comm: syz.0.5543 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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:1622
 dummy_timer+0x500/0x3820 drivers/usb/gadget/udc/dummy_hcd.c:1894
 __run_hrtimer kernel/time/hrtimer.c:2074 [inline]
 __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2131
 hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2148
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
 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:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:206
Code: 96 33 61 00 48 89 df 5b e9 0d 17 67 00 be 03 00 00 00 5b e9 22 20 1f 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 65 48 8b 05 ac bd 81 13 48 8b 34 24 65 48 8b 15 90 bd
RSP: 0018:ffffc90005ccf2b8 EFLAGS: 00000287
RAX: 0000000000001621 RBX: 0000000000000200 RCX: ffffc9002763c000
RDX: 0000000000080000 RSI: ffffffff81d0d64f RDI: ffff888026308000
RBP: 0000000000000040 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000001
R13: 001fffffffc00000 R14: 001fffffffc00040 R15: 1ffff92000b99e5a
 __cancel_work+0x245/0x340 kernel/workqueue.c:4549
 __cancel_work_sync kernel/workqueue.c:4556 [inline]
 cancel_work_sync+0x1d/0xf0 kernel/workqueue.c:4605
 snd_rawmidi_input_trigger sound/core/rawmidi.c:222 [inline]
 snd_rawmidi_input_trigger sound/core/rawmidi.c:216 [inline]
 snd_rawmidi_drain_input+0xdb/0x280 sound/core/rawmidi.c:297
 snd_rawmidi_input_params+0x53/0x1d0 sound/core/rawmidi.c:773
 midisynth_subscribe+0x199/0x410 sound/core/seq/seq_midi.c:218
 subscribe_port sound/core/seq/seq_ports.c:434 [inline]
 check_and_subscribe_port+0x86b/0xc50 sound/core/seq/seq_ports.c:516
 snd_seq_port_connect+0x306/0x540 sound/core/seq/seq_ports.c:589
 snd_seq_ioctl_subscribe_port+0x219/0x490 sound/core/seq/seq_clientmgr.c:1521
 call_seq_client_ctl+0xa3/0x130 sound/core/seq/seq_clientmgr.c:2467
 snd_seq_kernel_client_ctl+0x35/0x50 sound/core/seq/seq_clientmgr.c:2495
 snd_seq_oss_midi_open+0x465/0x680 sound/core/seq/oss/seq_oss_midi.c:350
 snd_seq_oss_synth_setup_midi+0x131/0x590 sound/core/seq/oss/seq_oss_synth.c:247
 snd_seq_oss_open+0x82e/0xa10 sound/core/seq/oss/seq_oss_init.c:255
 odev_open+0x6f/0x90 sound/core/seq/oss/seq_oss.c:128
 soundcore_open+0x2e3/0x5a0 sound/sound_core.c:594
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4866 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5029
 do_file_open+0x20e/0x430 fs/namei.c:5058
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f68fec
Code: Unable to access opcode bytes at 0xf7f68fc2.
RSP: 002b:00000000f541650c EFLAGS: 00000292 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000800001c0
RDX: 0000000000028000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 5820:
 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]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 snd_mixer_oss_build_test+0x7a/0x380 sound/core/oss/mixer_oss.c:893
 snd_mixer_oss_build_test_all+0x33c/0x6e0 sound/core/oss/mixer_oss.c:963
 snd_mixer_oss_build_input+0x139/0xd50 sound/core/oss/mixer_oss.c:1017
 snd_mixer_oss_build sound/core/oss/mixer_oss.c:1276 [inline]
 snd_mixer_oss_notify_handler+0x48d/0x990 sound/core/oss/mixer_oss.c:1344
 snd_card_register+0x2af/0x760 sound/core/init.c:936
 try_to_register_card+0x1d6/0x390 sound/usb/card.c:903
 usb_audio_probe+0x9f4/0x3b10 sound/usb/card.c:1080
 usb_probe_interface+0x386/0x9b0 drivers/usb/core/driver.c:399
 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
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3776
 usb_set_configuration+0xd97/0x1dc0 drivers/usb/core/message.c:2274
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:293
 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
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3776
 usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2713
 usb_new_device include/linux/workqueue.h:715 [inline]
 hub_port_connect drivers/usb/core/hub.c:5585 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event.cold+0x1e3/0xe90 drivers/usb/core/hub.c:5971
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5820:
 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:2748 [inline]
 slab_free mm/slub.c:6509 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6802
 __free_kfree include/linux/slab.h:599 [inline]
 snd_mixer_oss_build_test+0x118/0x380 sound/core/oss/mixer_oss.c:892
 snd_mixer_oss_build_test_all+0x33c/0x6e0 sound/core/oss/mixer_oss.c:963
 snd_mixer_oss_build_input+0x139/0xd50 sound/core/oss/mixer_oss.c:1017
 snd_mixer_oss_build sound/core/oss/mixer_oss.c:1276 [inline]
 snd_mixer_oss_notify_handler+0x48d/0x990 sound/core/oss/mixer_oss.c:1344
 snd_card_register+0x2af/0x760 sound/core/init.c:936
 try_to_register_card+0x1d6/0x390 sound/usb/card.c:903
 usb_audio_probe+0x9f4/0x3b10 sound/usb/card.c:1080
 usb_probe_interface+0x386/0x9b0 drivers/usb/core/driver.c:399
 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
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3776
 usb_set_configuration+0xd97/0x1dc0 drivers/usb/core/message.c:2274
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:293
 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
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3776
 usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2713
 usb_new_device include/linux/workqueue.h:715 [inline]
 hub_port_connect drivers/usb/core/hub.c:5585 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event.cold+0x1e3/0xe90 drivers/usb/core/hub.c:5971
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880794e4400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 274 bytes inside of
 freed 512-byte region [ffff8880794e4400, ffff8880794e4600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880794e4000 pfn:0x794e4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000240 ffff88801d042c80 ffffea0001883810 ffffea00013add10
raw: ffff8880794e4000 0000000000100006 00000000f5000000 0000000000000000
head: 04fff00000000240 ffff88801d042c80 ffffea0001883810 ffffea00013add10
head: ffff8880794e4000 0000000000100006 00000000f5000000 0000000000000000
head: 04fff00000000002 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 15073, tgid 15072 (syz.0.1496), ts 464066505535
 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:7418
 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]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 snd_mixer_oss_build_test+0x7a/0x380 sound/core/oss/mixer_oss.c:893
 snd_mixer_oss_build_test_all+0x1ac/0x6e0 sound/core/oss/mixer_oss.c:948
 snd_mixer_oss_build_input+0x139/0xd50 sound/core/oss/mixer_oss.c:1017
 snd_mixer_oss_build sound/core/oss/mixer_oss.c:1276 [inline]
 snd_mixer_oss_notify_handler+0x48d/0x990 sound/core/oss/mixer_oss.c:1344
 snd_card_register+0x2af/0x760 sound/core/init.c:936
 f_midi2_create_card drivers/usb/gadget/function/f_midi2.c:1615 [inline]
 f_midi2_bind+0x1198/0x2770 drivers/usb/gadget/function/f_midi2.c:1947
 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
page last free pid 65 tgid 65 ts 458955829558 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_node_track_caller_noprof+0x2da/0x870 mm/slub.c:5545
 kvasprintf+0xbc/0x150 lib/kasprintf.c:25
 kasprintf+0xc7/0x100 lib/kasprintf.c:59
 device_get_devnode+0xb5/0x2c0 drivers/base/core.c:4060
 devtmpfs_delete_node+0xc8/0x1d0 drivers/base/devtmpfs.c:163
 device_del+0x717/0x9b0 drivers/base/core.c:3944
 usb_disconnect+0x5b5/0x9a0 drivers/usb/core/hub.c:2386
 hub_port_connect drivers/usb/core/hub.c:5425 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event+0x1bb1/0x4420 drivers/usb/core/hub.c:5971
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158

Memory state around the buggy address:
 ffff8880794e4400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880794e4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880794e4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880794e4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880794e4600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	96                   	xchg   %eax,%esi
   1:	33 61 00             	xor    0x0(%rcx),%esp
   4:	48 89 df             	mov    %rbx,%rdi
   7:	5b                   	pop    %rbx
   8:	e9 0d 17 67 00       	jmp    0x67171a
   d:	be 03 00 00 00       	mov    $0x3,%esi
  12:	5b                   	pop    %rbx
  13:	e9 22 20 1f 03       	jmp    0x31f203a
  18:	66 90                	xchg   %ax,%ax
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	90                   	nop
  28:	90                   	nop
  29:	90                   	nop
* 2a:	f3 0f 1e fa          	endbr64 <-- trapping instruction
  2e:	65 48 8b 05 ac bd 81 	mov    %gs:0x1381bdac(%rip),%rax        # 0x1381bde2
  35:	13
  36:	48 8b 34 24          	mov    (%rsp),%rsi
  3a:	65                   	gs
  3b:	48                   	rex.W
  3c:	8b                   	.byte 0x8b
  3d:	15                   	.byte 0x15
  3e:	90                   	nop
  3f:	bd                   	.byte 0xbd