==================================================================
BUG: KASAN: use-after-free in snd_card_do_free sound/core/init.c:604 [inline]
BUG: KASAN: use-after-free in release_card_device+0x17d/0x1a0 sound/core/init.c:153
Read of size 1 at addr ffff888034c80909 by task syz.1.1061/9393

CPU: 1 UID: 0 PID: 9393 Comm: syz.1.1061 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:
 <TASK>
 __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
 snd_card_do_free sound/core/init.c:604 [inline]
 release_card_device+0x17d/0x1a0 sound/core/init.c:153
 device_release+0xd2/0x270 drivers/base/core.c:2636
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f7/0x640 lib/kobject.c:737
 put_device+0x1f/0x30 drivers/base/core.c:3880
 snd_card_file_remove+0x38f/0x560 sound/core/init.c:1125
 snd_pcm_oss_release+0x217/0x300 sound/core/oss/pcm_oss.c:2596
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x951/0x2ae0 kernel/exit.c:1009
 __do_sys_exit kernel/exit.c:1119 [inline]
 __se_sys_exit kernel/exit.c:1117 [inline]
 __x64_sys_exit+0x42/0x50 kernel/exit.c:1117
 x64_sys_call+0x152e/0x1530 arch/x86/include/generated/asm/syscalls_64.h:61
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f479ef9e0d9
Code: Unable to access opcode bytes at 0x7f479ef9e0af.
RSP: 002b:00007f479feddfd8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007f479f226090 RCX: 00007f479ef9e0d9
RDX: 00007f479fede9c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f479f035024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f479f226128 R14: 00007f479f226090 R15: 00007ffdc5527d48
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34c80
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00015e0008 ffff88806a441500 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_ZERO|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 17657869862, free_ts 171052011533
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
 ___kmalloc_large_node+0xe5/0x120 mm/slub.c:5274
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5305
 __do_kmalloc_node mm/slub.c:5322 [inline]
 __kmalloc_node_track_caller_noprof+0x5ac/0x830 mm/slub.c:5471
 alloc_dr drivers/base/devres.c:141 [inline]
 __devres_alloc_node+0x6e/0x1e0 drivers/base/devres.c:189
 snd_devm_card_new+0x9d/0x190 sound/core/init.c:235
 loopback_probe+0x140/0x11a0 sound/drivers/aloop.c:1805
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 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
page last free pid 10572 tgid 10571 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
 free_node drivers/base/devres.c:50 [inline]
 release_nodes+0xc3/0x120 drivers/base/devres.c:547
 devres_release_all+0x112/0x180 drivers/base/devres.c:576
 device_unbind_cleanup+0x81/0x270 drivers/base/dd.c:597
 __device_release_driver drivers/base/dd.c:1354 [inline]
 device_release_driver_internal+0x4c4/0x620 drivers/base/dd.c:1372
 unbind_store+0xf8/0x110 drivers/base/bus.c:244
 drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888034c80800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888034c80880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888034c80900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff888034c80980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888034c80a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================