linux-kernel - [PATCH] ALSA: hda: cs35l41: fix double free in cs35l41_hda

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Date:   Sat,  8 Jan 2022 06:07:56 -0800
From:   trix@...hat.com
To:     james.schulman@...rus.com, david.rhodes@...rus.com,
        tanureal@...nsource.cirrus.com, perex@...ex.cz, tiwai@...e.com,
        nathan@...nel.org, ndesaulniers@...gle.com
Cc:     alsa-devel@...a-project.org, patches@...nsource.cirrus.com,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        Tom Rix <trix@...hat.com>
Subject: [PATCH] ALSA: hda: cs35l41: fix double free in cs35l41_hda_probe()

From: Tom Rix <trix@...hat.com>

Clang static analysis reports this problem
cs35l41_hda.c:501:2: warning: Attempt to free released memory
        kfree(acpi_hw_cfg);
        ^~~~~~~~~~~~~~~~~~

This second free happens in the function's error handler which
is normally ok but acpi_hw_cfg is freed in the non error case
when it is still possible to have an error.

Consolidate the frees.

Fixes: 7b2f3eb492da ("ALSA: hda: cs35l41: Add support for CS35L41 in HDA systems")
Signed-off-by: Tom Rix <trix@...hat.com>
---
 sound/pci/hda/cs35l41_hda.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/sound/pci/hda/cs35l41_hda.c b/sound/pci/hda/cs35l41_hda.c
index aa5bb6977792c..265ace98965f5 100644
--- a/sound/pci/hda/cs35l41_hda.c
+++ b/sound/pci/hda/cs35l41_hda.c
@@ -476,7 +476,6 @@ int cs35l41_hda_probe(struct device *dev, const char *device_name, int id, int i
 	ret = cs35l41_hda_apply_properties(cs35l41, acpi_hw_cfg);
 	if (ret)
 		goto err;
-	kfree(acpi_hw_cfg);
 
 	if (cs35l41->reg_seq->probe) {
 		ret = regmap_register_patch(cs35l41->regmap, cs35l41->reg_seq->probe,
@@ -495,13 +494,14 @@ int cs35l41_hda_probe(struct device *dev, const char *device_name, int id, int i
 
 	dev_info(cs35l41->dev, "Cirrus Logic CS35L41 (%x), Revision: %02X\n", regid, reg_revid);
 
-	return 0;
-
 err:
 	kfree(acpi_hw_cfg);
-	if (!cs35l41->vspk_always_on)
-		gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
-	gpiod_put(cs35l41->reset_gpio);
+
+	if (unlikely(ret)) {
+		if (!cs35l41->vspk_always_on)
+			gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
+		gpiod_put(cs35l41->reset_gpio);
+	}
 
 	return ret;
 }
-- 
2.26.3