Re: [PATCH net-next] eth: fbnic: fix memory corruption in fbnic_tlv_attr_get_string()
From: Lee Trager <hidden>
Date: 2025-03-07 22:59:36
Also in:
kernel-janitors, lkml
From: Lee Trager <hidden>
Date: 2025-03-07 22:59:36
Also in:
kernel-janitors, lkml
On 3/7/25 1:28 AM, Dan Carpenter wrote:
This code is trying to ensure that the last byte of the buffer is a NUL terminator. However, the problem is that attr->value[] is an array of __le32, not char, so it zeroes out 4 bytes way beyond the end of the buffer. Cast the buffer to char to address this. Fixes: e5cf5107c9e4 ("eth: fbnic: Update fbnic_tlv_attr_get_string() to work like nla_strscpy()") Signed-off-by: Dan Carpenter <redacted> --- drivers/net/ethernet/meta/fbnic/fbnic_tlv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c b/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c index d558d176e0df..517ed8b2f1cb 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_tlv.c@@ -261,7 +261,7 @@ ssize_t fbnic_tlv_attr_get_string(struct fbnic_tlv_msg *attr, char *dst, return -E2BIG; srclen = le16_to_cpu(attr->hdr.len) - sizeof(*attr); - if (srclen > 0 && attr->value[srclen - 1] == '\0') + if (srclen > 0 && ((char *)attr->value)[srclen - 1] == '\0') srclen--; if (srclen >= dstsize) {
Thanks for catching that. While I didn't see any negative effect without it I have verified on hardware this patch works. Reviewed-by: Lee Trager <redacted>