WARNING in release_card_device

Status: upstream: reported syz repro on 2026/08/20 05:05
Reported-by: syzbot+b7853d20962a499a1d62@syzkaller.appspotmail.com
First crash: 10d, last: 3d19h

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4474 at mm/slab_common.c:904 free_large_kmalloc+0x30/0x158 mm/slab_common.c:905
Modules linked in:
CPU: 0 PID: 4474 Comm: syz.3.20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
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 : ffff800021997840
x29: ffff800021997840 x28: ffff0000d6241e10 x27: 1ffff00002d393d4
x26: 1fffe0001ab0c91e x25: 1fffe0001ab0c925 x24: 000000000000000d
x23: dfff800000000000 x22: dfff800000000000 x21: 0000000000040000
x20: ffff0000d5864080 x19: fffffc0003561900 x18: 1fffe00033e7037e
x17: ffff80001538d000 x16: ffff800011b9e758 x15: 0000000040000000
x14: 0000000000000001 x13: 1fffe00033e72a70 x12: 0000000000000000
x11: ff0080000808d058 x10: ffffffffffffffff x9 : 0000000000000000
x8 : ffff800017d6e000 x7 : ffff80000825ab48 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : ffff800021997520 x1 : ffff0000d5864080 x0 : fffffc0003561900
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_release+0x120/0x14c sound/core/pcm_native.c:2939
 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: 15526
hardirqs last  enabled at (15525): [<ffff80000825abdc>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1374 [inline]
hardirqs last  enabled at (15525): [<ffff80000825abdc>] finish_lock_switch+0xb0/0x1c8 kernel/sched/core.c:5005
hardirqs last disabled at (15526): [<ffff800011b9a994>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (15500): [<ffff8000081ae3b4>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last  enabled at (15500): [<ffff8000081ae3b4>] handle_softirqs+0xb1c/0xc90 kernel/softirq.c:624
softirqs last disabled at (15349): [<ffff800008020e6c>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
object pointer: 0x0000000063e19b70
==================================================================
BUG: KASAN: invalid-free in kfree+0xf4/0x1a8 mm/slab_common.c:982
Free of addr ffff0000d5864080 by task syz.3.20/4474

CPU: 0 PID: 4474 Comm: syz.3.20 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
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_invalid_free+0x98/0xe4 mm/kasan/report.c:489
 ____kasan_kfree_large mm/kasan/common.c:-1 [inline]
 __kasan_kfree_large+0xa4/0xc0 mm/kasan/common.c:273
 kasan_kfree_large include/linux/kasan.h:185 [inline]
 free_large_kmalloc+0x68/0x158 mm/slab_common.c:908
 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_release+0x120/0x14c sound/core/pcm_native.c:2939
 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:00000000baa304fa refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115864
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d5863f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d5864000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000d5864080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff0000d5864100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d5864180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/26 23:03 linux-6.1.y 05208478041c a2b77b9e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in release_card_device
2026/08/26 19:24 linux-6.1.y 05208478041c a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in release_card_device
2026/08/26 07:21 linux-6.1.y 05208478041c 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in release_card_device
2026/08/21 20:33 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in release_card_device
2026/08/21 08:53 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in release_card_device
2026/08/20 05:04 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in release_card_device
* Struck through repros no longer work on HEAD.