[v6.1] KASAN: use-after-free Read in release_card_device

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=145578c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f
dashboard link: https://syzkaller.appspot.com/bug?extid=7dd58bbfcf207cdb201d
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d420eb944682/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/affae450ab23/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9e6919ed519/Image-fb28aa72.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7dd58b...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in snd_card_do_free sound/core/init.c:612 [inline]
BUG: KASAN: use-after-free in release_card_device+0x188/0x198 sound/core/init.c:145
Read of size 1 at addr ffff0000d587cd99 by task syz.3.209/5232

CPU: 1 PID: 5232 Comm: syz.3.209 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Call trace:
dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack+0x30/0x40 lib/dump_stack.c:88
dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
print_address_description+0x88/0x218 mm/kasan/report.c:316
print_report+0x50/0x68 mm/kasan/report.c:420
kasan_report+0xa8/0xfc mm/kasan/report.c:524
__asan_report_load1_noabort+0x2c/0x38 mm/kasan/report_generic.c:348
snd_card_do_free sound/core/init.c:612 [inline]
release_card_device+0x188/0x198 sound/core/init.c:145
device_release+0x94/0x1b4 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x2a8/0x41c lib/kobject.c:729
put_device+0x28/0x40 drivers/base/core.c:3820
snd_card_file_remove+0x2e4/0x340 sound/core/init.c:1147
snd_pcm_oss_release+0x1e4/0x230 sound/core/oss/pcm_oss.c:2597
snd_disconnect_release+0x224/0x298 sound/core/init.c:438
__fput+0x1b4/0x7b0 fs/file_table.c:320
____fput+0x20/0x30 fs/file_table.c:348
task_work_run+0x1f4/0x280 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the physical page:
page:00000000898d10f0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11587c
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003ba2b08 ffff00019f3ce0b0 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff0000d587cc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000d587cd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000d587cd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff0000d587ce00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000d587ce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5232 at mm/slab_common.c:904 free_large_kmalloc+0x30/0x158 mm/slab_common.c:905
Modules linked in:
CPU: 1 PID: 5232 Comm: syz.3.209 Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
pstate: 42400005 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : free_large_kmalloc+0x30/0x158 mm/slab_common.c:905
lr : kfree+0xf4/0x1a8 mm/slab_common.c:982
sp : ffff800020e37830
x29: ffff800020e37830 x28: ffff0000caa1bf10 x27: 1ffff00002d37378
x26: 1fffe0001ab0f91e x25: 1fffe0001ab0f925 x24: 000000000000000d
x23: dfff800000000000 x22: dfff800000000000 x21: 0000000000040000
x20: ffff0000d587c080 x19: fffffc0003561f00 x18: 1fffe00033e7697e
x17: ffff80001537d000 x16: ffff800011b90080 x15: 0000000040000000
x14: 0000000000000001 x13: 1ffff00002ff016c x12: 0000000000000000
x11: ff0080000808d058 x10: ffffffffffffffff x9 : 0000000000000000
x8 : ffff800017d5d000 x7 : ffff800011cec160 x6 : ffff80000825ab50
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800008195a38
x2 : 0000000000000001 x1 : ffff0000d587c080 x0 : fffffc0003561f00
Call trace:
free_large_kmalloc+0x30/0x158 mm/slab_common.c:905
kfree+0xf4/0x1a8 mm/slab_common.c:982
snd_card_do_free sound/core/init.c:613 [inline]
release_card_device+0x130/0x198 sound/core/init.c:145
device_release+0x94/0x1b4 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x2a8/0x41c lib/kobject.c:729
put_device+0x28/0x40 drivers/base/core.c:3820
snd_card_file_remove+0x2e4/0x340 sound/core/init.c:1147
snd_pcm_oss_release+0x1e4/0x230 sound/core/oss/pcm_oss.c:2597
snd_disconnect_release+0x224/0x298 sound/core/init.c:438
__fput+0x1b4/0x7b0 fs/file_table.c:320
____fput+0x20/0x30 fs/file_table.c:348
task_work_run+0x1f4/0x280 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 18551
hardirqs last enabled at (18551): [<ffff80000825abe4>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1374 [inline]
hardirqs last enabled at (18551): [<ffff80000825abe4>] finish_lock_switch+0xb0/0x1c8 kernel/sched/core.c:5005
hardirqs last disabled at (18550): [<ffff800011c630f8>] __schedule+0x294/0x1a6c kernel/sched/core.c:6461
softirqs last enabled at (18428): [<ffff8000081ae3bc>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last enabled at (18428): [<ffff8000081ae3bc>] handle_softirqs+0xb1c/0xc90 kernel/softirq.c:624
softirqs last disabled at (18415): [<ffff800008020e6c>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
object pointer: 0x00000000837825f9


---
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