From 04315b072d623ba9200612a4c5f5330f1eb28a27 Mon Sep 17 00:00:00 2001

From: Michal Kubecek <mkubecek@suse.cz>

Date: Sun, 23 Aug 2020 21:40:24 +0200

Subject: [PATCH 05/17] ioctl: prevent argc underflow in do_perqueue()

When first command line argument after "-Q" is "queue_mask", we parse

the queue mask and following subcommand without checking if these

arguments do actually exist. Add check if we have at least two arguments

left after "queue_mask" in the corresponding branch.

Fixes: 9ecd54248b1a ("ethtool: introduce new ioctl for per-queue settings")

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>

(cherry picked from commit 39c354e591b66cc29edaab89f90ed03a513ad88f)

---

 ethtool.c | 2 ++

 1 file changed, 2 insertions(+)

diff --git a/ethtool.c b/ethtool.c

index 4fa7a2c1716f..6c12452be7b4 100644

--- a/ethtool.c

+++ b/ethtool.c

@@ -5880,6 +5880,8 @@ static int do_perqueue(struct cmd_context *ctx)

 			"The sub commands will be applied to all %d queues\n",

 			n_queues);

 	} else {

+		if (ctx->argc <= 2)

+			exit_bad_args();

 		ctx->argc--;

 		ctx->argp++;

 		if (parse_hex_u32_bitmap(*ctx->argp, MAX_NUM_QUEUE,

-- 

2.26.2