From c8c80c996182239ff9b05eda4db50184cf3b2e99 Mon Sep 17 00:00:00 2001
From: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Date: Thu, 13 Jan 2022 07:59:28 +0100
Subject: [PATCH] media: meson: vdec: potential dereference of null pointer
Git-commit: c8c80c996182239ff9b05eda4db50184cf3b2e99
Patch-mainline: v5.18-rc1
References: CVE-2022-3112 bsc#1206399

As the possible failure of the kzalloc(), the 'new_ts' could be NULL
pointer.
Therefore, it should be better to check it in order to avoid the
dereference of the NULL pointer.
Also, the caller esparser_queue() needs to deal with the return value of
the amvdec_add_ts().

Fixes: 876f123b8956 ("media: meson: vdec: bring up to compliance")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Suggested-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/media/meson/vdec/esparser.c     |    7 ++++++-
 drivers/staging/media/meson/vdec/vdec_helpers.c |    8 ++++++--
 drivers/staging/media/meson/vdec/vdec_helpers.h |    2 +-
 3 files changed, 13 insertions(+), 4 deletions(-)

--- a/drivers/staging/media/meson/vdec/esparser.c
+++ b/drivers/staging/media/meson/vdec/esparser.c
@@ -200,7 +200,12 @@ esparser_queue(struct amvdec_session *se
 
 	offset = esparser_get_offset(sess);
 
-	amvdec_add_ts_reorder(sess, vb->timestamp, offset);
+	ret = amvdec_add_ts_reorder(sess, vb->timestamp, offset);
+	if (ret) {
+		v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
+		return ret;
+	}
+
 	dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X\n",
 		vb->timestamp, payload_size, offset);
 
--- a/drivers/staging/media/meson/vdec/vdec_helpers.c
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
@@ -200,12 +200,15 @@ int amvdec_set_canvases(struct amvdec_se
 }
 EXPORT_SYMBOL_GPL(amvdec_set_canvases);
 
-void amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset)
+int amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset)
 {
 	struct amvdec_timestamp *new_ts, *tmp;
 	unsigned long flags;
 
-	new_ts = kmalloc(sizeof(*new_ts), GFP_KERNEL);
+	new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL);
+	if (!new_ts)
+		return -ENOMEM;
+
 	new_ts->ts = ts;
 	new_ts->offset = offset;
 
@@ -225,6 +228,7 @@ add_tail:
 	list_add_tail(&new_ts->list, &sess->timestamps);
 unlock:
 	spin_unlock_irqrestore(&sess->ts_spinlock, flags);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(amvdec_add_ts_reorder);
 
--- a/drivers/staging/media/meson/vdec/vdec_helpers.h
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.h
@@ -50,7 +50,7 @@ void amvdec_dst_buf_done_offset(struct a
  * @ts: timestamp to add
  * @offset: offset in the VIFIFO where the associated packet was written
  */
-void amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset);
+int amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset);
 void amvdec_remove_ts(struct amvdec_session *sess, u64 ts);
 
 /**