ALSA: core: Fix use-after-free in snd_card_do_free()
Summary
| CVE | CVE-2026-90198 |
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| State | PUBLISHED |
|---|
| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-09-17 17:17:14 UTC |
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| Updated | 2026-09-17 17:17:14 UTC |
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| Description | 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> |
|---|
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 d3d67f680dbc23a5e5e3d3ecfdbf700465809877 git |
Not specified |
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 09b27dd01b98480334c10bf6fb8d41d5fb063a4b git |
Not specified |
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 03c5dabc8f16bc212a5b26d2425c03a55e55a86d git |
Not specified |
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 6da22efb5cf490b06ffbca32b10fc8af7654fee0 git |
Not specified |
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 a561012868ae37c28f61fdf658bf6f251bc0e8e8 git |
Not specified |
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 7d9b5e86775fa97a487da08b9aa76e1674bf8868 git |
Not specified |
| CNA |
Linux |
Linux |
affected e8ad415b7a55cb9a9fbfc04696518d5ea0b609b3 5ae1a690c522fea2900ff56c8c2ace7b059f5e04 git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.15 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15.221 5.15.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.188 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.157 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.110 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.52 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.6 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/5ae1a690c522fea2900ff56c8c2ace7b059f5e04 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/6da22efb5cf490b06ffbca32b10fc8af7654fee0 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/a561012868ae37c28f61fdf658bf6f251bc0e8e8 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7d9b5e86775fa97a487da08b9aa76e1674bf8868 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/d3d67f680dbc23a5e5e3d3ecfdbf700465809877 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/03c5dabc8f16bc212a5b26d2425c03a55e55a86d |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/09b27dd01b98480334c10bf6fb8d41d5fb063a4b |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.