mm-camera2:isp2: Handle use after free buffer

In the code, start_fetch can try to access the
buffer pointer variable after free, as the
same pointer can be freed at RELEASE_BUF call
at the same time.

Change-Id: Ic83f22336504cf67afe12131f791eee25477f011
Signed-off-by: Meera Gande <mgande@codeaurora.org>

4 files changed, 13 insertions, 4 deletions

diff --git a/drivers/media/platform/msm/camera_v2/isp/msm_isp40.c b/drivers/media/platform/msm/camera_v2/isp/msm_isp40.c
index d3c418511ece..717e3750dcca 100644
--- a/drivers/media/platform/msm/camera_v2/isp/msm_isp40.c
+++ b/drivers/media/platform/msm/camera_v2/isp/msm_isp40.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1119,8 +1119,10 @@ static int msm_vfe40_start_fetch_engine_multi_pass(struct vfe_device *vfe_dev,
 				fe_cfg->stream_id);
 		vfe_dev->fetch_engine_info.bufq_handle = bufq_handle;
 
+		mutex_lock(&vfe_dev->buf_mgr->lock);
 		rc = vfe_dev->buf_mgr->ops->get_buf_by_index(
 			vfe_dev->buf_mgr, bufq_handle, fe_cfg->buf_idx, &buf);
+		mutex_unlock(&vfe_dev->buf_mgr->lock);
 		if (rc < 0 || !buf) {
 			pr_err("%s: No fetch buffer rc= %d buf= %pK\n",
 				__func__, rc, buf);
diff --git a/drivers/media/platform/msm/camera_v2/isp/msm_isp44.c b/drivers/media/platform/msm/camera_v2/isp/msm_isp44.c
index cc4dd5eaf93e..1d5035468134 100644
--- a/drivers/media/platform/msm/camera_v2/isp/msm_isp44.c
+++ b/drivers/media/platform/msm/camera_v2/isp/msm_isp44.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -891,8 +891,11 @@ static int msm_vfe44_fetch_engine_start(struct vfe_device *vfe_dev,
 			vfe_dev->buf_mgr, fe_cfg->session_id,
 			fe_cfg->stream_id);
 		vfe_dev->fetch_engine_info.bufq_handle = bufq_handle;
+
+		mutex_lock(&vfe_dev->buf_mgr->lock);
 		rc = vfe_dev->buf_mgr->ops->get_buf_by_index(
 			vfe_dev->buf_mgr, bufq_handle, fe_cfg->buf_idx, &buf);
+		mutex_unlock(&vfe_dev->buf_mgr->lock);
 		if (rc < 0) {
 			pr_err("%s: No fetch buffer\n", __func__);
 			return -EINVAL;
diff --git a/drivers/media/platform/msm/camera_v2/isp/msm_isp46.c b/drivers/media/platform/msm/camera_v2/isp/msm_isp46.c
index 632624034a04..42787c6c47db 100644
--- a/drivers/media/platform/msm/camera_v2/isp/msm_isp46.c
+++ b/drivers/media/platform/msm/camera_v2/isp/msm_isp46.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -833,8 +833,10 @@ static int msm_vfe46_start_fetch_engine(struct vfe_device *vfe_dev,
 			fe_cfg->stream_id);
 		vfe_dev->fetch_engine_info.bufq_handle = bufq_handle;
 
+		mutex_lock(&vfe_dev->buf_mgr->lock);
 		rc = vfe_dev->buf_mgr->ops->get_buf_by_index(
 			vfe_dev->buf_mgr, bufq_handle, fe_cfg->buf_idx, &buf);
+		mutex_unlock(&vfe_dev->buf_mgr->lock);
 		if (rc < 0 || !buf) {
 			pr_err("%s: No fetch buffer rc= %d buf= %pK\n",
 				__func__, rc, buf);
diff --git a/drivers/media/platform/msm/camera_v2/isp/msm_isp47.c b/drivers/media/platform/msm/camera_v2/isp/msm_isp47.c
index 146ed1f14467..121f1ab8bcd1 100644
--- a/drivers/media/platform/msm/camera_v2/isp/msm_isp47.c
+++ b/drivers/media/platform/msm/camera_v2/isp/msm_isp47.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1153,8 +1153,10 @@ int msm_vfe47_start_fetch_engine_multi_pass(struct vfe_device *vfe_dev,
 			fe_cfg->stream_id);
 		vfe_dev->fetch_engine_info.bufq_handle = bufq_handle;
 
+		mutex_lock(&vfe_dev->buf_mgr->lock);
 		rc = vfe_dev->buf_mgr->ops->get_buf_by_index(
 			vfe_dev->buf_mgr, bufq_handle, fe_cfg->buf_idx, &buf);
+		mutex_unlock(&vfe_dev->buf_mgr->lock);
 		if (rc < 0 || !buf) {
 			pr_err("%s: No fetch buffer rc= %d buf= %pK\n",
 				__func__, rc, buf);