Commit 25d0dc4b authored by Ashok Raj's avatar Ashok Raj Committed by Borislav Petkov (AMD)
Browse files

x86/microcode: Allow only "1" as a late reload trigger value 



Microcode gets reloaded late only if "1" is written to the reload file.
However, the code silently treats any other unsigned integer as a
successful write even though no actions are performed to load microcode.

Make the loader more strict to accept only "1" as a trigger value and
return an error otherwise.

  [ bp: Massage commit message. ]

Suggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230130213955.6046-3-ashok.raj@intel.com
parent a9a5cac2

arch/x86/kernel/cpu/microcode/core.c

+2 −5
Original line number Diff line number Diff line
@@ -475,11 +475,8 @@ static ssize_t reload_store(struct device *dev, 
	ssize_t ret = 0;



	ret = kstrtoul(buf, 0, &val);

	if (ret)

		return ret;



	if (val != 1)

		return size;

	if (ret || val != 1)

		return -EINVAL;



	cpus_read_lock();