Commit 5eff88dd authored by Rasmus Villemoes's avatar Rasmus Villemoes Committed by Ard Biesheuvel
Browse files

efi: cper: fix scnprintf() use in cper_mem_err_location() 



The last two if-clauses fail to update n, so whatever they might have
written at &msg[n] would be cut off by the final nul-termination.

That nul-termination is redundant; scnprintf(), just like snprintf(),
guarantees a nul-terminated output buffer, provided the buffer size is
positive.

And there's no need to discount one byte from the initial buffer;
vsnprintf() expects to be given the full buffer size - it's not going
to write the nul-terminator one beyond the given (buffer, size) pair.

Signed-off-by: default avatarRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent e73f0f0e

drivers/firmware/efi/cper.c

+5 −6
Original line number Diff line number Diff line
@@ -221,7 +221,7 @@ static int cper_mem_err_location(struct cper_mem_err_compact *mem, char *msg) 
		return 0;



	n = 0;

	len = CPER_REC_LEN - 1;

	len = CPER_REC_LEN;

	if (mem->validation_bits & CPER_MEM_VALID_NODE)

		n += scnprintf(msg + n, len - n, "node: %d ", mem->node);

	if (mem->validation_bits & CPER_MEM_VALID_CARD)
@@ -258,13 +258,12 @@ static int cper_mem_err_location(struct cper_mem_err_compact *mem, char *msg) 
		n += scnprintf(msg + n, len - n, "responder_id: 0x%016llx ",

			       mem->responder_id);

	if (mem->validation_bits & CPER_MEM_VALID_TARGET_ID)

		scnprintf(msg + n, len - n, "target_id: 0x%016llx ",

		n += scnprintf(msg + n, len - n, "target_id: 0x%016llx ",

			       mem->target_id);

	if (mem->validation_bits & CPER_MEM_VALID_CHIP_ID)

		scnprintf(msg + n, len - n, "chip_id: %d ",

		n += scnprintf(msg + n, len - n, "chip_id: %d ",

			       mem->extended >> CPER_MEM_CHIP_ID_SHIFT);



	msg[n] = '\0';

	return n;

}