From: syzbot <syzbot+7061d72c26b7daebe2b4@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org,
perex@perex.cz, syzkaller-bugs@googlegroups.com, tiwai@suse.com
Subject: [syzbot] [sound?] KASAN: use-after-free Read in release_card_device
Date: Tue, 04 Aug 2026 17:12:23 -0700 [thread overview]
Message-ID: <6a727fe7.13623e66.bdc14.003c.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 0131b508c0e2 Merge tag 'ntfs-for-7.2-rc6' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=109f4c9e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=7061d72c26b7daebe2b4
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/237b6b227f6e/disk-0131b508.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/90a5294c2a5d/vmlinux-0131b508.xz
kernel image: https://storage.googleapis.com/syzbot-assets/54d17924c110/bzImage-0131b508.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7061d72c26b7daebe2b4@syzkaller.appspotmail.com
==================================================================
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 ffff88814a70c909 by task syz.5.630/8206
CPU: 0 UID: 0 PID: 8206 Comm: syz.5.630 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 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_group_exit+0xd5/0x2a0 kernel/exit.c:1152
get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f883d59e019
Code: Unable to access opcode bytes at 0x7f883d59dfef.
RSP: 002b:00007f883e4a40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f883d825fa8 RCX: 00007f883d59e019
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f883d825fa8
RBP: 00007f883d825fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f883d826038 R14: 00007fff416628d0 R15: 00007fff416629b8
</TASK>
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14a70c
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 ffff8880b8541800 ffff8880b8541800 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 17137786410, free_ts 237675753363
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 8220 tgid 8219 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:
ffff88814a70c800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88814a70c880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88814a70c900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88814a70c980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88814a70ca00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
---
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reply other threads:[~2026-08-05 0:12 UTC|newest]
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