[PATCH] ALSA: hda: cs35l41: fix double free in cs35l41_hda_probe()
From: Tom Rix trix@redhat.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@redhat.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; }
On Saturday, January 8, 2022, trix@redhat.com wrote:
From: Tom Rix trix@redhat.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@redhat.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)) {
This is double weird. First of all, wtf unlikely is here? Second, I commented on the patch that does something with this driver and pointed out to the return 0 in some cases. This one seems a band aid.
if (!cs35l41->vspk_always_on)gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);gpiod_put(cs35l41->reset_gpio);} return ret;}
2.26.3
On 1/9/22 2:33 PM, Andy Shevchenko wrote:
On Saturday, January 8, 2022, <trix@redhat.com mailto:trix@redhat.com> wrote:
From: Tom Rix <trix@redhat.com <mailto:trix@redhat.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@redhat.com <mailto:trix@redhat.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)) {This is double weird. First of all, wtf unlikely is here? Second, I commented on the patch that does something with this driver and pointed out to the return 0 in some cases. This one seems a band aid.
Unlikely to have an error.
+ if (!cs35l41->vspk_always_on) + gpiod_set_value_cansleep(cs35l41->reset_gpio, 0); + gpiod_put(cs35l41->reset_gpio); + } return ret; } -- 2.26.3-- With Best Regards, Andy Shevchenko
On Mon, Jan 10, 2022 at 2:37 AM Tom Rix trix@redhat.com wrote:
On 1/9/22 2:33 PM, Andy Shevchenko wrote: On Saturday, January 8, 2022, trix@redhat.com wrote:
...
if (unlikely(ret)) {This is double weird. First of all, wtf unlikely is here? Second, I commented on the patch that does something with this driver and pointed out to the return 0 in some cases. This one seems a band aid.
Unlikely to have an error.
We don't use likely() and unlikely() here and there, you need to provide a very good justification of its use.
For the record, I forwarded you my review against the code where you can find much more issues with it that are subject to fix / amend.
On Mon, 10 Jan 2022 11:21:11 +0100, Andy Shevchenko wrote:
On Mon, Jan 10, 2022 at 2:37 AM Tom Rix trix@redhat.com wrote:
On 1/9/22 2:33 PM, Andy Shevchenko wrote: On Saturday, January 8, 2022, trix@redhat.com wrote:
...
if (unlikely(ret)) {This is double weird. First of all, wtf unlikely is here? Second, I commented on the patch that does something with this driver and pointed out to the return 0 in some cases. This one seems a band aid.
Unlikely to have an error.
We don't use likely() and unlikely() here and there, you need to provide a very good justification of its use.
For the record, I forwarded you my review against the code where you can find much more issues with it that are subject to fix / amend.
For this particular bug fix, Dan submitted a simpler patch and I took it now: https://lore.kernel.org/r/20220111072232.GG11243@kili
thanks,
Takashi
participants (4)
-
Andy Shevchenko -
Takashi Iwai -
Tom Rix -
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