[PATCH v2 2/4] drm/connector: hdmi: Fix memory leak in drm_display_mode_from_cea_vic()

From: Jinjie Ruan
Date: Mon Oct 14 2024 - 08:53:42 EST


modprobe drm_connector_test and then rmmod drm_connector_test,
the following memory leak occurs.

The `mode` allocated in drm_mode_duplicate() called by
drm_display_mode_from_cea_vic() is not freed, which cause the memory leak:

unreferenced object 0xffffff80cb0ee400 (size 128):
comm "kunit_try_catch", pid 1948, jiffies 4294950339
hex dump (first 32 bytes):
14 44 02 00 80 07 d8 07 04 08 98 08 00 00 38 04 .D............8.
3c 04 41 04 65 04 00 00 05 00 00 00 00 00 00 00 <.A.e...........
backtrace (crc 90e9585c):
[<00000000ec42e3d7>] kmemleak_alloc+0x34/0x40
[<00000000d0ef055a>] __kmalloc_cache_noprof+0x26c/0x2f4
[<00000000c2062161>] drm_mode_duplicate+0x44/0x19c
[<00000000f96c74aa>] drm_display_mode_from_cea_vic+0x88/0x98
[<00000000d8f2c8b4>] 0xffffffdc982a4868
[<000000005d164dbc>] kunit_try_run_case+0x13c/0x3ac
[<000000006fb23398>] kunit_generic_run_threadfn_adapter+0x80/0xec
[<000000006ea56ca0>] kthread+0x2e8/0x374
[<000000000676063f>] ret_from_fork+0x10/0x20
......

Free `mode` by using drm_kunit_helper_display_mode_from_cea_vic()
to fix it.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: abb6f74973e2 ("drm/tests: Add HDMI TDMS character rate tests")
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
v2:
- Fix it with new introduced helper instead of drm_mode_destroy().
- Update the commit message.
---
drivers/gpu/drm/tests/drm_connector_test.c | 24 +++++++++++-----------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_connector_test.c b/drivers/gpu/drm/tests/drm_connector_test.c
index 15e36a8db685..e12b39dc4fe7 100644
--- a/drivers/gpu/drm/tests/drm_connector_test.c
+++ b/drivers/gpu/drm/tests/drm_connector_test.c
@@ -996,7 +996,7 @@ static void drm_test_drm_hdmi_compute_mode_clock_rgb(struct kunit *test)
unsigned long long rate;
struct drm_device *drm = &priv->drm;

- mode = drm_display_mode_from_cea_vic(drm, 16);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 16);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1017,7 +1017,7 @@ static void drm_test_drm_hdmi_compute_mode_clock_rgb_10bpc(struct kunit *test)
unsigned long long rate;
struct drm_device *drm = &priv->drm;

- mode = drm_display_mode_from_cea_vic(drm, 16);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 16);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1038,7 +1038,7 @@ static void drm_test_drm_hdmi_compute_mode_clock_rgb_10bpc_vic_1(struct kunit *t
unsigned long long rate;
struct drm_device *drm = &priv->drm;

- mode = drm_display_mode_from_cea_vic(drm, 1);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 1);
KUNIT_ASSERT_NOT_NULL(test, mode);

rate = drm_hdmi_compute_mode_clock(mode, 10, HDMI_COLORSPACE_RGB);
@@ -1056,7 +1056,7 @@ static void drm_test_drm_hdmi_compute_mode_clock_rgb_12bpc(struct kunit *test)
unsigned long long rate;
struct drm_device *drm = &priv->drm;

- mode = drm_display_mode_from_cea_vic(drm, 16);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 16);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1077,7 +1077,7 @@ static void drm_test_drm_hdmi_compute_mode_clock_rgb_12bpc_vic_1(struct kunit *t
unsigned long long rate;
struct drm_device *drm = &priv->drm;

- mode = drm_display_mode_from_cea_vic(drm, 1);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 1);
KUNIT_ASSERT_NOT_NULL(test, mode);

rate = drm_hdmi_compute_mode_clock(mode, 12, HDMI_COLORSPACE_RGB);
@@ -1095,7 +1095,7 @@ static void drm_test_drm_hdmi_compute_mode_clock_rgb_double(struct kunit *test)
unsigned long long rate;
struct drm_device *drm = &priv->drm;

- mode = drm_display_mode_from_cea_vic(drm, 6);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 6);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_TRUE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1118,7 +1118,7 @@ static void drm_test_connector_hdmi_compute_mode_clock_yuv420_valid(struct kunit
unsigned long long rate;
unsigned int vic = *(unsigned int *)test->param_value;

- mode = drm_display_mode_from_cea_vic(drm, vic);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, vic);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1155,7 +1155,7 @@ static void drm_test_connector_hdmi_compute_mode_clock_yuv420_10_bpc(struct kuni
drm_hdmi_compute_mode_clock_yuv420_vic_valid_tests[0];
unsigned long long rate;

- mode = drm_display_mode_from_cea_vic(drm, vic);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, vic);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1180,7 +1180,7 @@ static void drm_test_connector_hdmi_compute_mode_clock_yuv420_12_bpc(struct kuni
drm_hdmi_compute_mode_clock_yuv420_vic_valid_tests[0];
unsigned long long rate;

- mode = drm_display_mode_from_cea_vic(drm, vic);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, vic);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1203,7 +1203,7 @@ static void drm_test_connector_hdmi_compute_mode_clock_yuv422_8_bpc(struct kunit
struct drm_device *drm = &priv->drm;
unsigned long long rate;

- mode = drm_display_mode_from_cea_vic(drm, 16);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 16);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1225,7 +1225,7 @@ static void drm_test_connector_hdmi_compute_mode_clock_yuv422_10_bpc(struct kuni
struct drm_device *drm = &priv->drm;
unsigned long long rate;

- mode = drm_display_mode_from_cea_vic(drm, 16);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 16);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
@@ -1247,7 +1247,7 @@ static void drm_test_connector_hdmi_compute_mode_clock_yuv422_12_bpc(struct kuni
struct drm_device *drm = &priv->drm;
unsigned long long rate;

- mode = drm_display_mode_from_cea_vic(drm, 16);
+ mode = drm_kunit_helper_display_mode_from_cea_vic(test, drm, 16);
KUNIT_ASSERT_NOT_NULL(test, mode);

KUNIT_ASSERT_FALSE(test, mode->flags & DRM_MODE_FLAG_DBLCLK);
--
2.34.1