published January 13, 2026
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: fw_tracer, Validate format string parameters
Add validation for format string parameters in the firmware tracer to
prevent potential security vulnerabilities and crashes from malformed
format strings received from firmware.
The firmware tracer receives format strings from the device firmware and
uses them to format trace messages. Without proper validation, bad
firmware could provide format strings with invalid format specifiers
(e.g., %s, %p, %n) that could lead to crashes, or other undefined
behavior.
Add mlx5_tracer_validate_params() to validate that all format specifiers
in trace strings are limited to safe integer/hex formats (%x, %d, %i,
%u, %llx, %lx, etc.). Reject strings containing other format types that
could be used to access arbitrary memory or cause crashes.
Invalid format strings are added to the trace output for visibility with
"BAD_FORMAT: " prefix.