Re: [PATCH] drm/amd/display: Fix memory leak

From: Harry Wentland
Date: Fri Jan 21 2022 - 14:03:28 EST

On 2022-01-21 06:26, Yongzhi Liu wrote:
> [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@xxxxxxxxxx>

Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>

Harry

> ---
> .../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;