2022-03-28 21:52:09

by QintaoShen

Subject: [PATCH v1] MIPS: ip22-gio: Add check for the return value of kzalloc()

Since the memory allocation function kzalloc() may return a NULL pointer,
the use of 'gio_dev' may lead to NULL pointer dereference.

So it is better to check the return value of kzalloc().

Signed-off-by: QintaoShen <[email protected]>
---
arch/mips/sgi-ip22/ip22-gio.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
index dfc52f6..df7ca21 100644
--- a/arch/mips/sgi-ip22/ip22-gio.c
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -363,7 +363,11 @@ static void ip22_check_gio(int slotno, unsigned long addr, int irq)
printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
slotno, name, id);
gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
- gio_dev->name = name;
+
+ if (!gio_dev)
+ return ;
+
+ gio_dev->name = name;
gio_dev->slotno = slotno;
gio_dev->id.id = id;
gio_dev->resource.start = addr;
--
2.7.4

2022-03-29 15:09:25

by Sergey Shtylyov

Subject: Re: [PATCH v1] MIPS: ip22-gio: Add check for the return value of kzalloc()

Hello!

On 3/28/22 11:04 AM, QintaoShen wrote:

> Since the memory allocation function kzalloc() may return a NULL pointer,
> the use of 'gio_dev' may lead to NULL pointer dereference.
>
> So it is better to check the return value of kzalloc().
>
> Signed-off-by: QintaoShen <[email protected]>
> ---
> arch/mips/sgi-ip22/ip22-gio.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
> index dfc52f6..df7ca21 100644
> --- a/arch/mips/sgi-ip22/ip22-gio.c
> +++ b/arch/mips/sgi-ip22/ip22-gio.c
> @@ -363,7 +363,11 @@ static void ip22_check_gio(int slotno, unsigned long addr, int irq)
> printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
> slotno, name, id);
> gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
> - gio_dev->name = name;
> +
> + if (!gio_dev)

Indented too little. And indent with tabs please, not spaces.

> + return ;

No need for space before ';'.

[...]

MBR, Sergey

2022-04-01 16:29:40

by Sergey Shtylyov

Subject: Re: [PATCH v1] MIPS: ip22-gio: Add check for the return value of kzalloc()

On 3/30/22 7:03 AM, unSimple wrote:

> OK, here is the new version.

That won't do, your original patch description should be here.
And it should be a fresh posting with [PATCH v2] in the subject.

> Signed-off-by: QintaoShen <[email protected]>
> ---

You need to describe what changes between v1 and v2 here...

>  arch/mips/sgi-ip22/ip22-gio.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
> index dfc52f6..f94f58b 100644
> --- a/arch/mips/sgi-ip22/ip22-gio.c
> +++ b/arch/mips/sgi-ip22/ip22-gio.c
> @@ -363,6 +363,10 @@ static void ip22_check_gio(int slotno, unsigned long addr, int irq)
>  printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
>         slotno, name, id);
>  gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
> +

No need for empty line here.

> +if (!gio_dev)
> +return;

Hm, the tabs were there but they got eaten when I replied.
Your mail seems to be base64-encoded which I don't think is
acceptable for patches -- they should be posted as plain text.

[...]

MBR, Sergey