2022-03-25 19:05:22

by Xiaoke Wang

Subject: [PATCH] MIPS: lantiq: check the return value of kzalloc()

From: Xiaoke Wang <[email protected]>

kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to check the
return value of it to prevent potential wrong memory access or
memory leak.

Signed-off-by: Xiaoke Wang <[email protected]>
---
arch/mips/lantiq/falcon/sysctrl.c | 2 ++
arch/mips/lantiq/xway/gptu.c | 2 ++
arch/mips/lantiq/xway/sysctrl.c | 46 ++++++++++++++++++++-----------
3 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/arch/mips/lantiq/falcon/sysctrl.c b/arch/mips/lantiq/falcon/sysctrl.c
index 42222f8..446a253 100644
--- a/arch/mips/lantiq/falcon/sysctrl.c
+++ b/arch/mips/lantiq/falcon/sysctrl.c
@@ -167,6 +167,8 @@ static inline void clkdev_add_sys(const char *dev, unsigned int module,
{
struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);

+ if (!clk)
+ return;
clk->cl.dev_id = dev;
clk->cl.con_id = NULL;
clk->cl.clk = clk;
diff --git a/arch/mips/lantiq/xway/gptu.c b/arch/mips/lantiq/xway/gptu.c
index 3d5683e..200fe9f 100644
--- a/arch/mips/lantiq/xway/gptu.c
+++ b/arch/mips/lantiq/xway/gptu.c
@@ -122,6 +122,8 @@ static inline void clkdev_add_gptu(struct device *dev, const char *con,
{
struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);

+ if (!clk)
+ return;
clk->cl.dev_id = dev_name(dev);
clk->cl.con_id = con;
clk->cl.clk = clk;
diff --git a/arch/mips/lantiq/xway/sysctrl.c b/arch/mips/lantiq/xway/sysctrl.c
index 917fac1..084f6ca 100644
--- a/arch/mips/lantiq/xway/sysctrl.c
+++ b/arch/mips/lantiq/xway/sysctrl.c
@@ -315,6 +315,8 @@ static void clkdev_add_pmu(const char *dev, const char *con, bool deactivate,
{
struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);

+ if (!clk)
+ return;
clk->cl.dev_id = dev;
clk->cl.con_id = con;
clk->cl.clk = clk;
@@ -338,6 +340,8 @@ static void clkdev_add_cgu(const char *dev, const char *con,
{
struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);

+ if (!clk)
+ return;
clk->cl.dev_id = dev;
clk->cl.con_id = con;
clk->cl.clk = clk;
@@ -356,24 +360,28 @@ static void clkdev_add_pci(void)
struct clk *clk_ext = kzalloc(sizeof(struct clk), GFP_KERNEL);

/* main pci clock */
- clk->cl.dev_id = "17000000.pci";
- clk->cl.con_id = NULL;
- clk->cl.clk = clk;
- clk->rate = CLOCK_33M;
- clk->rates = valid_pci_rates;
- clk->enable = pci_enable;
- clk->disable = pmu_disable;
- clk->module = 0;
- clk->bits = PMU_PCI;
- clkdev_add(&clk->cl);
+ if (clk) {
+ clk->cl.dev_id = "17000000.pci";
+ clk->cl.con_id = NULL;
+ clk->cl.clk = clk;
+ clk->rate = CLOCK_33M;
+ clk->rates = valid_pci_rates;
+ clk->enable = pci_enable;
+ clk->disable = pmu_disable;
+ clk->module = 0;
+ clk->bits = PMU_PCI;
+ clkdev_add(&clk->cl);
+ }

/* use internal/external bus clock */
- clk_ext->cl.dev_id = "17000000.pci";
- clk_ext->cl.con_id = "external";
- clk_ext->cl.clk = clk_ext;
- clk_ext->enable = pci_ext_enable;
- clk_ext->disable = pci_ext_disable;
- clkdev_add(&clk_ext->cl);
+ if (clk_ext) {
+ clk_ext->cl.dev_id = "17000000.pci";
+ clk_ext->cl.con_id = "external";
+ clk_ext->cl.clk = clk_ext;
+ clk_ext->enable = pci_ext_enable;
+ clk_ext->disable = pci_ext_disable;
+ clkdev_add(&clk_ext->cl);
+ }
}

/* xway socs can generate clocks on gpio pins */
@@ -393,9 +401,15 @@ static void clkdev_add_clkout(void)
char *name;

name = kzalloc(sizeof("clkout0"), GFP_KERNEL);
+ if (!name)
+ continue;
sprintf(name, "clkout%d", i);

clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+ if (!clk) {
+ kfree(name);
+ continue;
+ }
clk->cl.dev_id = "1f103000.cgu";
clk->cl.con_id = name;
clk->cl.clk = clk;
--

2022-03-31 04:47:27

by Thomas Bogendoerfer

Subject: Re: [PATCH] MIPS: lantiq: check the return value of kzalloc()

On Fri, Mar 25, 2022 at 07:49:41PM +0800, [email protected] wrote:
> From: Xiaoke Wang <[email protected]>
>
> kzalloc() is a memory allocation function which can return NULL when
> some internal memory errors happen. So it is better to check the
> return value of it to prevent potential wrong memory access or
> memory leak.
>
> Signed-off-by: Xiaoke Wang <[email protected]>
> ---
> arch/mips/lantiq/falcon/sysctrl.c | 2 ++
> arch/mips/lantiq/xway/gptu.c | 2 ++
> arch/mips/lantiq/xway/sysctrl.c | 46 ++++++++++++++++++++-----------
> 3 files changed, 34 insertions(+), 16 deletions(-)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]