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From:   Yongzhi Liu <lyz_cs@pku.edu.cn>
To:     harry.wentland@amd.com, sunpeng.li@amd.com,
        Rodrigo.Siqueira@amd.com, alexander.deucher@amd.com,
        christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@linux.ie,
        daniel@ffwll.ch, mikita.lipski@amd.com, Wayne.Lin@amd.com,
        Nicholas.Kazlauskas@amd.com, Jerry.Zuo@amd.com,
        Anson.Jacob@amd.com, eryk.brol@amd.com, aurabindo.pillai@amd.com,
        nirmoy.das@amd.com, lyz_cs@pku.edu.cn
Cc:     amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] drm/amd/display: Fix memory leak
Date:   Fri, 21 Jan 2022 03:26:13 -0800
Message-Id: <1642764373-48563-1-git-send-email-lyz_cs@pku.edu.cn>
Precedence: bulk

[why]
Resource release is needed on the error handling path
to prevent memory leak.

[how]
Fix this by adding kfree on the error handling path.

Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn>
---
 .../drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c  | 80 ++++++++++++++++------
 1 file changed, 60 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index ded64d0..e463d46 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -227,8 +227,10 @@ static ssize_t dp_link_settings_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -389,8 +391,10 @@ static ssize_t dp_phy_settings_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user((*(rd_buf + result)), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -1359,8 +1363,10 @@ static ssize_t dp_dsc_clock_en_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -1376,8 +1382,10 @@ static ssize_t dp_dsc_clock_en_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -1546,8 +1554,10 @@ static ssize_t dp_dsc_slice_width_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -1563,8 +1573,10 @@ static ssize_t dp_dsc_slice_width_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -1731,8 +1743,10 @@ static ssize_t dp_dsc_slice_height_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -1748,8 +1762,10 @@ static ssize_t dp_dsc_slice_height_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -1912,8 +1928,10 @@ static ssize_t dp_dsc_bits_per_pixel_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -1929,8 +1947,10 @@ static ssize_t dp_dsc_bits_per_pixel_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -2088,8 +2108,10 @@ static ssize_t dp_dsc_pic_width_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -2105,8 +2127,10 @@ static ssize_t dp_dsc_pic_width_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -2145,8 +2169,10 @@ static ssize_t dp_dsc_pic_height_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -2162,8 +2188,10 @@ static ssize_t dp_dsc_pic_height_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -2217,8 +2245,10 @@ static ssize_t dp_dsc_chunk_size_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -2234,8 +2264,10 @@ static ssize_t dp_dsc_chunk_size_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -2289,8 +2321,10 @@ static ssize_t dp_dsc_slice_bpg_offset_read(struct file *f, char __user *buf,
 				break;
 	}
 
-	if (!pipe_ctx)
+	if (!pipe_ctx) {
+		kfree(rd_buf);
 		return -ENXIO;
+	}
 
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
@@ -2306,8 +2340,10 @@ static ssize_t dp_dsc_slice_bpg_offset_read(struct file *f, char __user *buf,
 			break;
 
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 
 		buf += 1;
 		size -= 1;
@@ -3459,8 +3495,10 @@ static ssize_t dcc_en_bits_read(
 	dc->hwss.get_dcc_en_bits(dc, dcc_en_bits);
 
 	rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
-	if (!rd_buf)
+	if (!rd_buf) {
+		kfree(dcc_en_bits);
 		return -ENOMEM;
+	}
 
 	for (i = 0; i < num_pipes; i++)
 		offset += snprintf(rd_buf + offset, rd_buf_size - offset,
@@ -3473,8 +3511,10 @@ static ssize_t dcc_en_bits_read(
 		if (*pos >= rd_buf_size)
 			break;
 		r = put_user(*(rd_buf + result), buf);
-		if (r)
+		if (r) {
+			kfree(rd_buf);
 			return r; /* r = -EFAULT */
+		}
 		buf += 1;
 		size -= 1;
 		*pos += 1;
-- 
2.7.4