[PATCH v2 4/4] drm/tests: hdmi: Fix memory leaks in drm_display_mode_from_cea_vic()

From: Jinjie Ruan
Date: Mon Oct 14 2024 - 08:53:30 EST


modprobe drm_hdmi_state_helper_test and then rmmod it, 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 0xffffff80ccd18100 (size 128):
comm "kunit_try_catch", pid 1851, jiffies 4295059695
hex dump (first 32 bytes):
57 62 00 00 80 02 90 02 f0 02 20 03 00 00 e0 01 Wb........ .....
ea 01 ec 01 0d 02 00 00 0a 00 00 00 00 00 00 00 ................
backtrace (crc c2f1aa95):
[<000000000f10b11b>] kmemleak_alloc+0x34/0x40
[<000000001cd4cf73>] __kmalloc_cache_noprof+0x26c/0x2f4
[<00000000f1f3cffa>] drm_mode_duplicate+0x44/0x19c
[<000000008cbeef13>] drm_display_mode_from_cea_vic+0x88/0x98
[<0000000019daaacf>] 0xffffffedc11ae69c
[<000000000aad0f85>] kunit_try_run_case+0x13c/0x3ac
[<00000000a9210bac>] kunit_generic_run_threadfn_adapter+0x80/0xec
[<000000000a0b2e9e>] kthread+0x2e8/0x374
[<00000000bd668858>] ret_from_fork+0x10/0x20
......

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

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 4af70f19e559 ("drm/tests: Add RGB Quantization 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_hdmi_state_helper_test.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
index 34ee95d41f29..bb9af542cb43 100644
--- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
@@ -441,7 +441,7 @@ static void drm_test_check_broadcast_rgb_auto_cea_mode_vic_1(struct kunit *test)
ctx = drm_kunit_helper_acquire_ctx_alloc(test);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

- 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);

drm = &priv->drm;
@@ -555,7 +555,7 @@ static void drm_test_check_broadcast_rgb_full_cea_mode_vic_1(struct kunit *test)
ctx = drm_kunit_helper_acquire_ctx_alloc(test);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

- 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);

drm = &priv->drm;
@@ -671,7 +671,7 @@ static void drm_test_check_broadcast_rgb_limited_cea_mode_vic_1(struct kunit *te
ctx = drm_kunit_helper_acquire_ctx_alloc(test);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

- 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);

drm = &priv->drm;
@@ -1263,7 +1263,7 @@ static void drm_test_check_output_bpc_format_vic_1(struct kunit *test)
ctx = drm_kunit_helper_acquire_ctx_alloc(test);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

- 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);

/*
--
2.34.1