From: Takashi Iwai <tiwai@suse.de>

Date: Wed, 11 Mar 2020 09:50:37 +0100

Subject: [PATCH] nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow

Git-commit: 8d8a50e20dc2dc41cb788085968b9024dc36f7a5

Patch-mainline: v5.7-rc1

References: bsc#1161930

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>

Acked-by: Hannes Reinecke <hare@suse.com>

---

 drivers/nvme/host/fabrics.c | 8 ++++----

 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c

index 74b8818ac9a1..2a6c8190eeb7 100644

--- 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;

 }

-- 

2.16.4