2023-08-04 01:47:14

by Su Hui

Subject: [PATCH v2] fs: lockd: avoid possible wrong NULL parameter

clang's static analysis warning: fs/lockd/mon.c: line 293, column 2:
Null pointer passed as 2nd argument to memory copy function.

Assuming 'hostname' is NULL and calling 'nsm_create_handle()', this will
pass NULL as 2nd argument to memory copy function 'memcpy()'. So return
NULL if 'hostname' is invalid.

Fixes: 77a3ef33e2de ("NSM: More clean up of nsm_get_handle()")
Signed-off-by: Su Hui <[email protected]>
---
v2:
- move NULL check to the callee "nsm_create_handle()"
fs/lockd/mon.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 1d9488cf0534..87a0f207df0b 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -276,6 +276,9 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
{
struct nsm_handle *new;

+ if (!hostname)
+ return NULL;
+
new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
if (unlikely(new == NULL))
return NULL;
--
2.30.2

2023-08-04 10:39:52

by Jeff Layton

Subject: Re: [PATCH v2] fs: lockd: avoid possible wrong NULL parameter

On Fri, 2023-08-04 at 09:26 +0800, Su Hui wrote:
> clang's static analysis warning: fs/lockd/mon.c: line 293, column 2:
> Null pointer passed as 2nd argument to memory copy function.
>
> Assuming 'hostname' is NULL and calling 'nsm_create_handle()', this will
> pass NULL as 2nd argument to memory copy function 'memcpy()'. So return
> NULL if 'hostname' is invalid.
>
> Fixes: 77a3ef33e2de ("NSM: More clean up of nsm_get_handle()")
> Signed-off-by: Su Hui <[email protected]>
> ---
> v2:
> - move NULL check to the callee "nsm_create_handle()"
> fs/lockd/mon.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
> index 1d9488cf0534..87a0f207df0b 100644
> --- a/fs/lockd/mon.c
> +++ b/fs/lockd/mon.c
> @@ -276,6 +276,9 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
> {
> struct nsm_handle *new;
>
> + if (!hostname)
> + return NULL;
> +
> new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
> if (unlikely(new == NULL))
> return NULL;

Reviewed-by: Jeff Layton <[email protected]>

2023-08-04 19:07:54

by Chuck Lever III

Subject: Re: [PATCH v2] fs: lockd: avoid possible wrong NULL parameter

On Fri, Aug 04, 2023 at 09:26:57AM +0800, Su Hui wrote:
> clang's static analysis warning: fs/lockd/mon.c: line 293, column 2:
> Null pointer passed as 2nd argument to memory copy function.
>
> Assuming 'hostname' is NULL and calling 'nsm_create_handle()', this will
> pass NULL as 2nd argument to memory copy function 'memcpy()'. So return
> NULL if 'hostname' is invalid.
>
> Fixes: 77a3ef33e2de ("NSM: More clean up of nsm_get_handle()")
> Signed-off-by: Su Hui <[email protected]>

Applied to nfsd-next (for v6.6).


> ---
> v2:
> - move NULL check to the callee "nsm_create_handle()"
> fs/lockd/mon.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
> index 1d9488cf0534..87a0f207df0b 100644
> --- a/fs/lockd/mon.c
> +++ b/fs/lockd/mon.c
> @@ -276,6 +276,9 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
> {
> struct nsm_handle *new;
>
> + if (!hostname)
> + return NULL;
> +
> new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
> if (unlikely(new == NULL))
> return NULL;
> --
> 2.30.2
>

--
Chuck Lever