CVEvulnerability
CVE-2026-90284
- Status
- Received
- Published
- 2026-09-17
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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.
References
- https://git.kernel.org/stable/c/5a250bff75a446374c05622973b18b4ab662b504 git.kernel.org
- https://git.kernel.org/stable/c/6eaa632d0ed7bbb84f9cb670e5ec4e2cecf4cc7b git.kernel.org
- https://git.kernel.org/stable/c/85aeb8fc61839098ae0942ccba86e669c08e75d4 git.kernel.org
- https://git.kernel.org/stable/c/93a2385730540105df8524447dcc11309ad280f9 git.kernel.org
- https://git.kernel.org/stable/c/b48373c901951fad1a26bd7c33ad91172b3945b5 git.kernel.org
- https://git.kernel.org/stable/c/c8b97c5130f27b64fa2cfe1aa4bebb13f724c6c7 git.kernel.org
- https://git.kernel.org/stable/c/ea33fac0df7fe7b49a4b27acb83e227b82317d1d git.kernel.org
- https://git.kernel.org/stable/c/fb4824880b0dba0e7b3a497c46c642f979630392 git.kernel.org