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: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> --- drivers/firmware/efi/cper.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c index e15d484b6a5a..dfa0bd140bef 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -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 ", - mem->target_id); + 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 ", - mem->extended >> CPER_MEM_CHIP_ID_SHIFT); + n += scnprintf(msg + n, len - n, "chip_id: %d ", + mem->extended >> CPER_MEM_CHIP_ID_SHIFT); - msg[n] = '\0'; return n; } -- 2.29.2
