From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 31 Jan 2019 13:16:25 +0000 (+0100)
Subject: ath9k: do not return invalid pointers as a *dentry
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=cd98625b3e3fd53b92323f781c0a80c039c23fbb;p=openwrt%2Fstaging%2Fblogic.git

ath9k: do not return invalid pointers as a *dentry

When calling debugfs functions, they can now return error values if
something went wrong.  If that happens, return a NULL as a *dentry to
the relay core instead of passing it an illegal pointer.

The relay core should be able to handle an illegal pointer, but add this
check to be safe.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: QCA ath9k Development <ath9k-devel@qca.qualcomm.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---

diff --git a/drivers/net/wireless/ath/ath9k/common-spectral.c b/drivers/net/wireless/ath/ath9k/common-spectral.c
index 6aa3ec024ffa..21191955a7c1 100644
--- a/drivers/net/wireless/ath/ath9k/common-spectral.c
+++ b/drivers/net/wireless/ath/ath9k/common-spectral.c
@@ -1039,6 +1039,9 @@ static struct dentry *create_buf_file_handler(const char *filename,
 
 	buf_file = debugfs_create_file(filename, mode, parent, buf,
 				       &relay_file_operations);
+	if (IS_ERR(buf_file))
+		return NULL;
+
 	*is_global = 1;
 	return buf_file;
 }