loop9: detected capacity change from 0 to 1024
==================================================================
BUG: KASAN: slab-use-after-free in dvb_device_open+0xc4/0x350 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff88802cbbc418 by task syz.9.4765/29330

CPU: 0 UID: 0 PID: 29330 Comm: syz.9.4765 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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
 dvb_device_open+0xc4/0x350 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411
 do_dentry_open+0x822/0x13a0 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x2e08/0x3860 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 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: 0033:0x7f7bf7d5d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f7bf8c4bb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7bf8c4c6c0 RCX: 00007f7bf7d5d68e
RDX: 0000000000000002 RSI: 00007f7bf8c4bc00 RDI: ffffffffffffff9c
RBP: 00007f7bf8c4bc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f7bf8016038 R14: 00007f7bf8015fa0 R15: 00007fffc9c484f8
 </TASK>

Allocated by task 27318:
 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]
 __do_kmalloc_node mm/slub.c:5296 [inline]
 __kmalloc_noprof+0x35c/0x760 mm/slub.c:5308
 kmalloc_noprof include/linux/slab.h:954 [inline]
 snd_midi_event_new+0x95/0x1e0 sound/core/seq/seq_midi_event.c:111
 snd_seq_midisynth_new sound/core/seq/seq_midi.c:161 [inline]
 snd_seq_midisynth_probe+0x568/0x1780 sound/core/seq/seq_midi.c:332
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7e9/0xbb0 drivers/base/core.c:3706
 snd_seq_device_dev_register+0x43/0xd0 sound/core/seq_device.c:192
 __snd_device_register sound/core/device.c:149 [inline]
 snd_device_register+0x12f/0x1c0 sound/core/device.c:179
 snd_rawmidi_dev_register+0x987/0xef0 sound/core/rawmidi.c:2036
 __snd_device_register sound/core/device.c:149 [inline]
 snd_device_register_all+0xd3/0x1b0 sound/core/device.c:197
 snd_card_register+0x1d3/0x720 sound/core/init.c:901
 try_to_register_card+0x62c/0x790 sound/usb/card.c:-1
 usb_audio_probe+0x1978/0x2380 sound/usb/card.c:1047
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7e9/0xbb0 drivers/base/core.c:3706
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7e9/0xbb0 drivers/base/core.c:3706
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 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 27318:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 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:2689 [inline]
 slab_free mm/slub.c:6251 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6566
 snd_midi_event_free+0x40/0x60 sound/core/seq/seq_midi_event.c:129
 snd_seq_midisynth_delete sound/core/seq/seq_midi.c:263 [inline]
 snd_seq_midisynth_remove+0x214/0x530 sound/core/seq/seq_midi.c:432
 device_remove drivers/base/dd.c:619 [inline]
 __device_release_driver drivers/base/dd.c:1352 [inline]
 device_release_driver_internal+0x46f/0x870 drivers/base/dd.c:1375
 bus_remove_device+0x455/0x570 drivers/base/bus.c:657
 device_del+0x527/0x8f0 drivers/base/core.c:3895
 snd_seq_device_dev_disconnect+0x3d/0x50 sound/core/seq_device.c:204
 __snd_device_disconnect sound/core/device.c:63 [inline]
 snd_device_disconnect_all+0xd7/0x210 sound/core/device.c:215
 snd_card_disconnect+0x3a0/0x7e0 sound/core/init.c:539
 __usb_audio_disconnect sound/usb/card.c:1112 [inline]
 usb_audio_disconnect+0x2d7/0x730 sound/usb/card.c:1160
 usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:621 [inline]
 __device_release_driver drivers/base/dd.c:1352 [inline]
 device_release_driver_internal+0x4d9/0x870 drivers/base/dd.c:1375
 bus_remove_device+0x455/0x570 drivers/base/bus.c:657
 device_del+0x527/0x8f0 drivers/base/core.c:3895
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x32f/0x990 drivers/usb/core/hub.c:2345
 hub_port_connect drivers/usb/core/hub.c:5407 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x1cc9/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 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

The buggy address belongs to the object at ffff88802cbbc400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 24 bytes inside of
 freed 256-byte region [ffff88802cbbc400, ffff88802cbbc500)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2cbbc
head: order:1 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 ffff88813fe17b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe17b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 10706666620, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
 prep_new_page mm/page_alloc.c:1861 [inline]
 get_page_from_freelist+0x2593/0x2610 mm/page_alloc.c:3941
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7272
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4652
 alloc_from_pcs mm/slub.c:4750 [inline]
 slab_alloc_node mm/slub.c:4884 [inline]
 __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 bus_add_driver+0x162/0x670 drivers/base/bus.c:740
 driver_register+0x23a/0x320 drivers/base/driver.c:249
 usb_register_driver+0x1e4/0x390 drivers/usb/core/driver.c:1078
 do_one_initcall+0x250/0x870 init/main.c:1392
 do_initcall_level+0x104/0x190 init/main.c:1454
 do_initcalls+0x59/0xa0 init/main.c:1470
 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
 kernel_init+0x1d/0x1d0 init/main.c:1593
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802cbbc300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802cbbc380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802cbbc400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802cbbc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802cbbc500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================