CVE-2026-90198ALSA: core: Fix use-after-free in snd_card_do_free()

In the Linux kernel, the following vulnerability has been resolved: ALSA: core: Fix use-after-free in snd_card_do_free() A use-after-free was detected in snd_card_do_free() when a sound card managed by devres is unbound while a user-space application still holds an open file descriptor. For managed cards, the memory is allocated using devres_alloc(), and its release function is set to __snd_card_release(), which calls snd_card_free(). When the device is unbound, the unbind thread calls snd_card_free(), which drops a reference to the card's device. If the user thread still has an open file descriptor, the reference count does not reach zero, and the unbind thread blocks on wait_for_completion(&released). When the user thread closes the file descriptor, it drops the final reference, invoking the device release callback release_card_device(), which calls snd_card_do_free(). snd_card_do_free() performs cleanup and calls complete(card->release_completion). This wakes up the unbind thread, which returns from snd_card_free() and __snd_card_release(). The devres core then immediately frees the memory block containing the snd_card structure. Meanwhile, the user thread continues execution in snd_card_do_free() and evaluates `if (!card->managed)`. It reads the `managed` boolean from the snd_card structure that was just freed by the unbind thread, triggering a KASAN use-after-free. Fix this by caching the value of card->managed in a local variable before calling complete(). This ensures that the card pointer is not dereferenced after the unbind thread has been woken up and potentially freed the card. 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+0x1ab/0x1b0 sound/core/init.c:153 Read of size 1 at addr ffff8881912ec909 by task syz-executor130/5857 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 snd_card_do_free sound/core/init.c:604 [inline] release_card_device+0x1ab/0x1b0 sound/core/init.c:153 device_release+0xc4/0x1f0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x222/0x550 lib/kobject.c:737 snd_card_file_remove+0x331/0x390 sound/core/init.c:1125 snd_pcm_release+0x12c/0x160 sound/core/pcm_native.c:2986 __fput+0x418/0xa50 fs/file_table.c:512 fput_close_sync+0x11f/0x240 fs/file_table.c:617 __do_sys_close fs/open.c:1511 [inline] __se_sys_close fs/open.c:1496 [inline] __x64_sys_close+0x7e/0x110 fs/open.c:1496 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 </TASK>

CVSS

Not yet scored

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Received

Record last updated

Oct 19, 2026

First seen by InfoSec Signals

Oct 9, 2026

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