nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 74b8818ac9a1e0aa0701c8077ce2b092f5ff60aa..2a6c8190eeb766fe724111818a78c84e5161ef27 100644 (file)
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -105,14 +105,14 @@ int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
        int len = 0;
 
        if (ctrl->opts->mask & NVMF_OPT_TRADDR)
-               len += snprintf(buf, size, "traddr=%s", ctrl->opts->traddr);
+               len += scnprintf(buf, size, "traddr=%s", ctrl->opts->traddr);
        if (ctrl->opts->mask & NVMF_OPT_TRSVCID)
-               len += snprintf(buf + len, size - len, "%strsvcid=%s",
+               len += scnprintf(buf + len, size - len, "%strsvcid=%s",
                                (len) ? "," : "", ctrl->opts->trsvcid);
        if (ctrl->opts->mask & NVMF_OPT_HOST_TRADDR)
-               len += snprintf(buf + len, size - len, "%shost_traddr=%s",
+               len += scnprintf(buf + len, size - len, "%shost_traddr=%s",
                                (len) ? "," : "", ctrl->opts->host_traddr);
-       len += snprintf(buf + len, size - len, "\n");
+       len += scnprintf(buf + len, size - len, "\n");
 
        return len;
 }