==================================================================
BUG: KASAN: slab-use-after-free in free_all_midi2_umps sound/usb/midi2.c:689 [inline]
BUG: KASAN: slab-use-after-free in snd_usb_midi_v2_free+0x602/0x7b0 sound/usb/midi2.c:941
Write of size 8 at addr ffff888032f9c350 by task syz.4.247/7238

CPU: 1 UID: 0 PID: 7238 Comm: syz.4.247 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 free_all_midi2_umps sound/usb/midi2.c:689 [inline]
 snd_usb_midi_v2_free+0x602/0x7b0 sound/usb/midi2.c:941
 snd_usb_midi_v2_free_all+0x67/0x90 sound/usb/midi2.c:1240
 snd_usb_audio_free+0x4c/0x100 sound/usb/card.c:608
 snd_card_do_free sound/core/init.c:594 [inline]
 release_card_device+0xab/0x1b0 sound/core/init.c:153
 device_release+0xc4/0x1f0 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+0x222/0x550 lib/kobject.c:737
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3961
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2345
 hub_disconnect_children drivers/usb/core/hub.c:2294 [inline]
 usb_disconnect+0x2b6/0x9a0 drivers/usb/core/hub.c:2338
 usb_remove_hcd+0x275/0x670 drivers/usb/core/hcd.c:3059
 dummy_hcd_remove+0xed/0x130 drivers/usb/gadget/udc/dummy_hcd.c:2761
 device_remove drivers/base/dd.c:616 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372
 unbind_store+0x1a1/0x1d0 drivers/base/bus.c:244
 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f963f79e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f96406c0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f963fa25fa0 RCX: 00007f963f79e0d9
RDX: 000000000000000b RSI: 0000200000000200 RDI: 0000000000000008
RBP: 00007f963f835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f963fa26038 R14: 00007f963fa25fa0 R15: 00007ffe266bdd58
 </TASK>

Allocated by task 5787:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x32d/0x660 mm/slub.c:5489
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 snd_ump_endpoint_new+0x7d/0x3d0 sound/core/ump.c:169
 create_midi2_ump+0x314/0x7b0 sound/usb/midi2.c:717
 find_matching_ep_partner sound/usb/midi2.c:781 [inline]
 parse_midi_2_0 sound/usb/midi2.c:973 [inline]
 snd_usb_midi_v2_create+0x140d/0x4ac0 sound/usb/midi2.c:1129
 snd_usb_create_stream+0x262/0x630 sound/usb/card.c:290
 snd_usb_create_streams sound/usb/card.c:392 [inline]
 usb_audio_probe+0x1447/0x2280 sound/usb/card.c:1031
 usb_probe_interface+0x653/0xc60 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3772
 usb_set_configuration+0x1ad8/0x2180 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3772
 usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2703
 hub_port_connect drivers/usb/core/hub.c:5575 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
 port_event drivers/usb/core/hub.c:5879 [inline]
 hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5961
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 7238:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2677 [inline]
 slab_free mm/slub.c:6377 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6692
 snd_rawmidi_free+0x400/0x420 sound/core/rawmidi.c:1936
 snd_rawmidi_dev_free+0x38/0x50 sound/core/rawmidi.c:1945
 __snd_device_free sound/core/device.c:76 [inline]
 snd_device_free_all+0x2c7/0x7a0 sound/core/device.c:233
 snd_card_do_free sound/core/init.c:592 [inline]
 release_card_device+0x75/0x1b0 sound/core/init.c:153
 device_release+0xc4/0x1f0 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+0x222/0x550 lib/kobject.c:737
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3961
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2345
 hub_disconnect_children drivers/usb/core/hub.c:2294 [inline]
 usb_disconnect+0x2b6/0x9a0 drivers/usb/core/hub.c:2338
 usb_remove_hcd+0x275/0x670 drivers/usb/core/hcd.c:3059
 dummy_hcd_remove+0xed/0x130 drivers/usb/gadget/udc/dummy_hcd.c:2761
 device_remove drivers/base/dd.c:616 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372
 unbind_store+0x1a1/0x1d0 drivers/base/bus.c:244
 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888032f9c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 848 bytes inside of
 freed 4096-byte region [ffff888032f9c000, ffff888032f9d000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32f98
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 ffff88801b005140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b005140 dead000000000100 dead000000000122
head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 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 6560, tgid 6560 (syz-executor), ts 258476544294, free_ts 253575760683
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab+0x79/0x5e0 mm/slub.c:3380
 new_slab mm/slub.c:3426 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __kmalloc_cache_noprof+0x3a7/0x660 mm/slub.c:5485
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 kobject_uevent_env+0x289/0x9e0 lib/kobject_uevent.c:543
 register_netdevice+0x19f4/0x1eb0 net/core/dev.c:11497
 register_netdev+0x40/0x60 net/core/dev.c:11563
 loopback_net_init+0x75/0x150 drivers/net/loopback.c:218
 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137
 setup_net+0x118/0x350 net/core/net_namespace.c:446
 copy_net_ns+0x4f9/0x720 net/core/net_namespace.c:579
 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
page last free pid 6656 tgid 6656 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950
 __slab_free+0x274/0x2c0 mm/slub.c:5741
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4584 [inline]
 slab_alloc_node mm/slub.c:4917 [inline]
 kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931
 new_handle fs/jbd2/transaction.c:457 [inline]
 jbd2__journal_start+0x145/0x5c0 fs/jbd2/transaction.c:485
 __ext4_journal_start_sb+0x203/0x5d0 fs/ext4/ext4_jbd2.c:114
 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline]
 ext4_dirty_inode+0x93/0x110 fs/ext4/inode.c:6636
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2709
 generic_update_time fs/inode.c:2257 [inline]
 file_update_time_flags+0x3ee/0x4a0 fs/inode.c:2487
 ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6805
 do_page_mkwrite+0x147/0x310 mm/memory.c:3684
 do_shared_fault mm/memory.c:5936 [inline]
 do_fault mm/memory.c:5998 [inline]
 do_pte_missing+0x757/0x34b0 mm/memory.c:4566
 handle_pte_fault mm/memory.c:6379 [inline]
 __handle_mm_fault mm/memory.c:6517 [inline]
 handle_mm_fault+0x1b36/0x3080 mm/memory.c:6686
 do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343

Memory state around the buggy address:
 ffff888032f9c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888032f9c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888032f9c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888032f9c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888032f9c400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================