2023-01-19 03:25:17

by ye.xingchen

Subject: [PATCH] ARM: mvebu: potential dereference of null pointer

From: Minghao Chi <[email protected]>

The return value of kzalloc() needs to be checked.
To avoid use of null pointer in case of the failure of alloc.

Reported-by: Zeal Robot <[email protected]>
Signed-off-by: Minghao Chi <[email protected]>
Signed-off-by: ye xingchen <[email protected]>
---
arch/arm/mach-mvebu/board-v7.c | 4 ++++
arch/arm/mach-mvebu/coherency.c | 4 ++++
2 files changed, 8 insertions(+)

diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c
index fd5d0c8ff695..3c031b2efe16 100644
--- a/arch/arm/mach-mvebu/board-v7.c
+++ b/arch/arm/mach-mvebu/board-v7.c
@@ -125,11 +125,15 @@ static void __init i2c_quirk(void)
struct property *new_compat;

new_compat = kzalloc(sizeof(*new_compat), GFP_KERNEL);
+ if (!new_compat)
+ return;

new_compat->name = kstrdup("compatible", GFP_KERNEL);
new_compat->length = sizeof("marvell,mv78230-a0-i2c");
new_compat->value = kstrdup("marvell,mv78230-a0-i2c",
GFP_KERNEL);
+ if (!new_compat->name || !new_compat->value)
+ return;

of_update_property(np, new_compat);
}
diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index a6b621ff0b87..8291185c52cc 100644
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -191,7 +191,11 @@ static void __init armada_375_380_coherency_init(struct device_node *np)
struct property *p;

p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return;
p->name = kstrdup("arm,io-coherent", GFP_KERNEL);
+ if (!p->name)
+ return;
of_add_property(cache_dn, p);
}
}
--
2.25.1

2023-01-19 13:56:50

by Andrew Lunn

Subject: Re: [PATCH] ARM: mvebu: potential dereference of null pointer

On Thu, Jan 19, 2023 at 10:51:18AM +0800, [email protected] wrote:
> From: Minghao Chi <[email protected]>
>
> The return value of kzalloc() needs to be checked.
> To avoid use of null pointer in case of the failure of alloc.
>
> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Minghao Chi <[email protected]>
> Signed-off-by: ye xingchen <[email protected]>

Reviewed-by: Andrew Lunn <[email protected]>

Andrew

2023-01-19 19:06:30

by Russell King (Oracle)

Subject: Re: [PATCH] ARM: mvebu: potential dereference of null pointer

On Thu, Jan 19, 2023 at 10:51:18AM +0800, [email protected] wrote:
> From: Minghao Chi <[email protected]>
>
> The return value of kzalloc() needs to be checked.
> To avoid use of null pointer in case of the failure of alloc.
>
> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Minghao Chi <[email protected]>
> Signed-off-by: ye xingchen <[email protected]>
> ---
> arch/arm/mach-mvebu/board-v7.c | 4 ++++
> arch/arm/mach-mvebu/coherency.c | 4 ++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c
> index fd5d0c8ff695..3c031b2efe16 100644
> --- a/arch/arm/mach-mvebu/board-v7.c
> +++ b/arch/arm/mach-mvebu/board-v7.c
> @@ -125,11 +125,15 @@ static void __init i2c_quirk(void)
> struct property *new_compat;
>
> new_compat = kzalloc(sizeof(*new_compat), GFP_KERNEL);
> + if (!new_compat)
> + return;
>
> new_compat->name = kstrdup("compatible", GFP_KERNEL);
> new_compat->length = sizeof("marvell,mv78230-a0-i2c");
> new_compat->value = kstrdup("marvell,mv78230-a0-i2c",
> GFP_KERNEL);
> + if (!new_compat->name || !new_compat->value)
> + return;

... and then someone else comes along and spots that "new_compat"
gets leaked, so we get another patch to add a kfree() for new_compat.

Why not do the job properly first time around?

> of_update_property(np, new_compat);
> }
> diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
> index a6b621ff0b87..8291185c52cc 100644
> --- a/arch/arm/mach-mvebu/coherency.c
> +++ b/arch/arm/mach-mvebu/coherency.c
> @@ -191,7 +191,11 @@ static void __init armada_375_380_coherency_init(struct device_node *np)
> struct property *p;
>
> p = kzalloc(sizeof(*p), GFP_KERNEL);
> + if (!p)
> + return;
> p->name = kstrdup("arm,io-coherent", GFP_KERNEL);
> + if (!p->name)
> + return;

Same problem here.

--
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