From: Alasdair G Kergon <agk@redhat.com>
Date: Tue, 2 Aug 2011 11:32:03 +0000 (+0100)
Subject: dm ioctl: prevent empty message
X-Git-Tag: firefly_0821_release~3680^2~4777^2~19
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2ca4c92f58f9386e080b26f9ccd78c9ca5825a42;p=firefly-linux-kernel-4.4.55.git

dm ioctl: prevent empty message

Detect invalid empty messages in core dm instead of requiring every target to
check this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 4cacdad2270a..1622a6bc0bfd 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1402,6 +1402,11 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
 		goto out;
 	}
 
+	if (!argc) {
+		DMWARN("Empty message received.");
+		goto out;
+	}
+
 	table = dm_get_live_table(md);
 	if (!table)
 		goto out_argv;