2023-12-08 09:00:10

by Kunwu Chan

[permalink] [raw]
Subject: [PATCH] powerpc/powernv: Add a null pointer check to scom_debug_init_one

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.
Add a null pointer check, and release 'ent' to avoid memory leaks.

Fixes: bfd2f0d49aef ("powerpc/powernv: Get rid of old scom_controller abstraction")
Cc: Kunwu Chan <[email protected]>
Signed-off-by: Kunwu Chan <[email protected]>
---
arch/powerpc/platforms/powernv/opal-xscom.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c
index 262cd6fac907..748c2b97fa53 100644
--- a/arch/powerpc/platforms/powernv/opal-xscom.c
+++ b/arch/powerpc/platforms/powernv/opal-xscom.c
@@ -165,6 +165,11 @@ static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
ent->chip = chip;
snprintf(ent->name, 16, "%08x", chip);
ent->path.data = (void *)kasprintf(GFP_KERNEL, "%pOF", dn);
+ if (!ent->path.data) {
+ kfree(ent);
+ return -ENOMEM;
+ }
+
ent->path.size = strlen((char *)ent->path.data);

dir = debugfs_create_dir(ent->name, root);
--
2.39.2


2023-12-18 04:58:05

by Andrew Donnellan

[permalink] [raw]
Subject: Re: [PATCH] powerpc/powernv: Add a null pointer check to scom_debug_init_one

On Fri, 2023-12-08 at 16:59 +0800, Kunwu Chan wrote:
> kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
> Add a null pointer check, and release 'ent' to avoid memory leaks.
>
> Fixes: bfd2f0d49aef ("powerpc/powernv: Get rid of old scom_controller
> abstraction")

[+ robh]

This commit just reshuffled around some existing code. The commit that
appears to have added this is actually b7c670d673d1 ("powerpc: Convert
to using %pOF instead of full_name").

> Cc: Kunwu Chan <[email protected]>
> Signed-off-by: Kunwu Chan <[email protected]>
> ---
>  arch/powerpc/platforms/powernv/opal-xscom.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c
> b/arch/powerpc/platforms/powernv/opal-xscom.c
> index 262cd6fac907..748c2b97fa53 100644
> --- a/arch/powerpc/platforms/powernv/opal-xscom.c
> +++ b/arch/powerpc/platforms/powernv/opal-xscom.c
> @@ -165,6 +165,11 @@ static int scom_debug_init_one(struct dentry
> *root, struct device_node *dn,
>   ent->chip = chip;
>   snprintf(ent->name, 16, "%08x", chip);
>   ent->path.data = (void *)kasprintf(GFP_KERNEL, "%pOF", dn);
> + if (!ent->path.data) {
> + kfree(ent);
> + return -ENOMEM;

The caller of this function (scom_debug_init()) uses a bitwise OR to
aggregate the return codes of multiple calls to scom_debug_init_one().
This doesn't really work for returning specific error codes, so I'd
just return -1 here (or change the way the return codes are handled on
the caller side).

> + }
> +
>   ent->path.size = strlen((char *)ent->path.data);
>  
>   dir = debugfs_create_dir(ent->name, root);

--
Andrew Donnellan OzLabs, ADL Canberra
[email protected] IBM Australia Limited

2023-12-21 10:42:07

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH] powerpc/powernv: Add a null pointer check to scom_debug_init_one

On Fri, 08 Dec 2023 16:59:37 +0800, Kunwu Chan wrote:
> kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
> Add a null pointer check, and release 'ent' to avoid memory leaks.
>
>

Applied to powerpc/next.

[1/1] powerpc/powernv: Add a null pointer check to scom_debug_init_one
https://git.kernel.org/powerpc/c/9a260f2dd827bbc82cc60eb4f4d8c22707d80742

cheers