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 <[email protected]>
---
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