From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     vaibhav.sr@gmail.com, mgreer@animalcreek.com, johan@kernel.org,
        elder@kernel.org, gregkh@linuxfoundation.org
Cc:     greybus-dev@lists.linaro.org, linux-staging@lists.linux.dev,
        linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] staging: greybus: audio: Check null pointer
Date:   Fri, 24 Dec 2021 17:03:36 +0800
Message-Id: <20211224090336.1612305-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

As the possible alloc failure of devm_kcalloc, it could return null
pointer.
To prevent the dereference of the null pointer, it should be checked.

Fixes: e65579e335da ("greybus: audio: topology: Enable enumerated control support")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 drivers/staging/greybus/audio_topology.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/staging/greybus/audio_topology.c b/drivers/staging/greybus/audio_topology.c
index 1fc7727ab7be..e9f47a1f0d28 100644
--- a/drivers/staging/greybus/audio_topology.c
+++ b/drivers/staging/greybus/audio_topology.c
@@ -146,7 +146,11 @@ static const char **gb_generate_enum_strings(struct gbaudio_module_info *gb,
 	__u8 *data;
 
 	items = le32_to_cpu(gbenum->items);
+
 	strings = devm_kcalloc(gb->dev, items, sizeof(char *), GFP_KERNEL);
+	if (!strings)
+		return NULL;
+
 	data = gbenum->names;
 
 	for (i = 0; i < items; i++) {
@@ -654,7 +658,10 @@ static int gbaudio_tplg_create_enum_kctl(struct gbaudio_module_info *gb,
 
 	/* since count=1, and reg is dummy */
 	gbe->items = le32_to_cpu(gb_enum->items);
+
 	gbe->texts = gb_generate_enum_strings(gb, gb_enum);
+	if (!gbe->texts)
+		return -ENOMEM;
 
 	/* debug enum info */
 	dev_dbg(gb->dev, "Max:%d, name_length:%d\n", gbe->items,
@@ -861,7 +868,10 @@ static int gbaudio_tplg_create_enum_ctl(struct gbaudio_module_info *gb,
 
 	/* since count=1, and reg is dummy */
 	gbe->items = le32_to_cpu(gb_enum->items);
+
 	gbe->texts = gb_generate_enum_strings(gb, gb_enum);
+	if (!gbe->texts)
+		return -ENOMEM;
 
 	/* debug enum info */
 	dev_dbg(gb->dev, "Max:%d, name_length:%d\n", gbe->items,
@@ -1032,8 +1042,12 @@ static int gbaudio_tplg_create_widget(struct gbaudio_module_info *module,
 			csize += offsetof(struct gb_audio_ctl_elem_info, value);
 			csize += offsetof(struct gb_audio_enumerated, names);
 			csize += le16_to_cpu(gbenum->names_length);
+
 			control->texts = (const char * const *)
 				gb_generate_enum_strings(module, gbenum);
+			if (!control->texts)
+				return -ENOMEM;
+
 			control->items = le32_to_cpu(gbenum->items);
 		} else {
 			csize = sizeof(struct gb_audio_control);
@@ -1181,8 +1195,12 @@ static int gbaudio_tplg_process_kcontrols(struct gbaudio_module_info *module,
 			csize += offsetof(struct gb_audio_ctl_elem_info, value);
 			csize += offsetof(struct gb_audio_enumerated, names);
 			csize += le16_to_cpu(gbenum->names_length);
+
 			control->texts = (const char * const *)
 				gb_generate_enum_strings(module, gbenum);
+			if (!control->texts)
+				return -ENOMEM;
+
 			control->items = le32_to_cpu(gbenum->items);
 		} else {
 			csize = sizeof(struct gb_audio_control);
-- 
2.25.1