# CVE-2023-53045: linux: In the Linux kernel, the following vulnerability has been resolved:  usb: gadget: u_audio: don't let userspace block...

CVE-2023-53045 is fixed in linux on 1 platform, first by DEBIAN-CVE-2023-53045, released May 2, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-53045
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0015
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 2, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  usb: gadget: u_audio: don't let userspace block driver unbind  In the unbind callback for f_uac1 and f_uac2, a call to snd_card_free() via g_audio_cleanup() will disconnect the card and then wait for all resources to be released, which happens when the refcount falls to zero. Since userspace can keep the refcount incremented by not closing the relevant file descriptor, the call to unbind may block indefinitely. This can cause a deadlock during reboot, as evidenced by the following blocked task observed on my machine:    task:reboot  state:D stack:0   pid:2827  ppid:569    flags:0x0000000c   Call trace:    __switch_to+0xc8/0x140    __schedule+0x2f0/0x7c0    schedule+0x60/0xd0    schedule_timeout+0x180/0x1d4    wait_for_completion+0x78/0x180    snd_card_free+0x90/0xa0    g_audio_cleanup+0x2c/0x64    afunc_unbind+0x28/0x60    ...    kernel_restart+0x4c/0xac    __do_sys_reboot+0xcc/0x1ec    __arm64_sys_reboot+0x28/0x30    invoke_syscall+0x4c/0x110    ...  The issue can also be observed by opening the card with arecord and then stopping the process through the shell before unbinding:    # arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null   Recording WAVE '/dev/null' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo   ^Z[1]+  Stopped                    arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null   # echo gadget.0 > /sys/bus/gadget/drivers/configfs-gadget/unbind   (observe that the unbind command never finishes)  Fix the problem by using snd_card_free_when_closed() instead, which will still disconnect the card as desired, but defer the task of freeing the resources to the core once userspace closes its file descriptor.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.25-1 | [DEBIAN-CVE-2023-53045](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53045.md) | May 2, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.1.25-1 | [DEBIAN-CVE-2023-53045](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53045.md) | May 2, 2025 |
| Linux | linux Debian 14 | 6.1.25-1 | [DEBIAN-CVE-2023-53045](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53045.md) | May 2, 2025 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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