[PATCH] selftests/net/ipsec: Fix Null pointer dereference in rtattr_pack()

[PATCH] selftests/net/ipsec: Fix Null pointer dereference in rtattr_pack()

[liuye]

    Fix the following warning.

    tools/testing/selftests/net/ipsec.c:230:25: warning: Possible null pointer
    dereference: payload [nullPointer]
    memcpy(RTA_DATA(attr), payload, size);
                           ^
    tools/testing/selftests/net/ipsec.c:1618:54: note: Calling function 'rtattr_pack',
    4th argument 'NULL' value is 0
    if (rtattr_pack(&req.nh, sizeof(req), XFRMA_IF_ID, NULL, 0)) {
                                                       ^
    tools/testing/selftests/net/ipsec.c:230:25: note: Null pointer dereference
    memcpy(RTA_DATA(attr), payload, size);
                           ^

Signed-off-by: liuye <liuye@kylinos.cn>
---
 tools/testing/selftests/net/ipsec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/ipsec.c b/tools/testing/selftests/net/ipsec.c
index be4a30a0d02a..725310ac26a9 100644
--- a/tools/testing/selftests/net/ipsec.c
+++ b/tools/testing/selftests/net/ipsec.c
@@ -227,7 +227,8 @@ static int rtattr_pack(struct nlmsghdr *nh, size_t req_sz,
 
 	attr->rta_len = RTA_LENGTH(size);
 	attr->rta_type = rta_type;
-	memcpy(RTA_DATA(attr), payload, size);
+	if (payload != NULL)
+		memcpy(RTA_DATA(attr), payload, size);
 
 	return 0;
 }
-- 
2.25.1

Re: [PATCH] selftests/net/ipsec: Fix Null pointer dereference in rtattr_pack()

[Simon Horman]

On Tue, Jan 14, 2025 at 03:43:29PM +0800, liuye wrote:
>     Fix the following warning.

I think it is a bit more than a warning, I'd phrase this more like,
even as it repeats the subject. Also, it would be nice to cite
the tool that generates the warning.

Address Null pointer dereference in rtattr_pack.

Flagged by ??? as:

> 
>     tools/testing/selftests/net/ipsec.c:230:25: warning: Possible null pointer
>     dereference: payload [nullPointer]
>     memcpy(RTA_DATA(attr), payload, size);
>                            ^
>     tools/testing/selftests/net/ipsec.c:1618:54: note: Calling function 'rtattr_pack',
>     4th argument 'NULL' value is 0
>     if (rtattr_pack(&req.nh, sizeof(req), XFRMA_IF_ID, NULL, 0)) {
>                                                        ^
>     tools/testing/selftests/net/ipsec.c:230:25: note: Null pointer dereference
>     memcpy(RTA_DATA(attr), payload, size);
>                            ^
> 

And I wonder if a fixes tag is appropriate, and if so this one:

70bfdf62e93a ("selftests/net/ipsec: Add test for xfrm_spdattr_type_t")

And, accordingly if this patch should be targeted at net:

	[PATCH net] ...

> Signed-off-by: liuye <liuye@kylinos.cn>

Please consider separating out your family and given name in hte
signed-off-by line. Perhaps Lin Ye (apologies if that is incorrect).

The above not withstanding, the code change looks good to me.
So feel free to include the following in a v2 with an updated patch
description.

> ---
>  tools/testing/selftests/net/ipsec.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/net/ipsec.c b/tools/testing/selftests/net/ipsec.c
> index be4a30a0d02a..725310ac26a9 100644
> --- a/tools/testing/selftests/net/ipsec.c
> +++ b/tools/testing/selftests/net/ipsec.c
> @@ -227,7 +227,8 @@ static int rtattr_pack(struct nlmsghdr *nh, size_t req_sz,
>  
>  	attr->rta_len = RTA_LENGTH(size);
>  	attr->rta_type = rta_type;
> -	memcpy(RTA_DATA(attr), payload, size);
> +	if (payload != NULL)

I think it would be more idiomatic to express this as:

	if (payload)

> +		memcpy(RTA_DATA(attr), payload, size);
>  
>  	return 0;
>  }
> -- 
> 2.25.1
> 

[PATCH net V2] selftests/net/ipsec: Fix Null pointer dereference in rtattr_pack()

[Liu Ye]

From: liuye <liuye@kylinos.cn>

From: Liu Ye <liuye@kylinos.cn>

Address Null pointer dereference in rtattr_pack.

Flagged by cppcheck as:
    tools/testing/selftests/net/ipsec.c:230:25: warning: Possible null pointer
    dereference: payload [nullPointer]
    memcpy(RTA_DATA(attr), payload, size);
                           ^
    tools/testing/selftests/net/ipsec.c:1618:54: note: Calling function 'rtattr_pack',
    4th argument 'NULL' value is 0
    if (rtattr_pack(&req.nh, sizeof(req), XFRMA_IF_ID, NULL, 0)) {
                                                       ^
    tools/testing/selftests/net/ipsec.c:230:25: note: Null pointer dereference
    memcpy(RTA_DATA(attr), payload, size);
                           ^
Fixes: 70bfdf62e93a ("selftests/net/ipsec: Add test for xfrm_spdattr_type_t")
---
V2: Modify description.
    Add code checking tools.
    Separating family and given name in Signed-off-by line.
    Modify code format.
    Add fixes.
---

Signed-off-by: Liu Ye <liuye@kylinos.cn>
---
 tools/testing/selftests/net/ipsec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/ipsec.c b/tools/testing/selftests/net/ipsec.c
index be4a30a0d02a..9b44a091802c 100644
--- a/tools/testing/selftests/net/ipsec.c
+++ b/tools/testing/selftests/net/ipsec.c
@@ -227,7 +227,8 @@ static int rtattr_pack(struct nlmsghdr *nh, size_t req_sz,
 
 	attr->rta_len = RTA_LENGTH(size);
 	attr->rta_type = rta_type;
-	memcpy(RTA_DATA(attr), payload, size);
+	if (payload)
+		memcpy(RTA_DATA(attr), payload, size);
 
 	return 0;
 }
-- 
2.25.1

Re: [PATCH net V2] selftests/net/ipsec: Fix Null pointer dereference in rtattr_pack()

[Jakub Kicinski]

On Wed, 15 Jan 2025 11:13:22 +0800 Liu Ye wrote:
> From: liuye <liuye@kylinos.cn>
> 
> From: Liu Ye <liuye@kylinos.cn>

too many From lines.

> Address Null pointer dereference in rtattr_pack.

I think size is 0 in the bad case, so it's more of an undefinied
behavior.

> Flagged by cppcheck as:
>     tools/testing/selftests/net/ipsec.c:230:25: warning: Possible null pointer
>     dereference: payload [nullPointer]
>     memcpy(RTA_DATA(attr), payload, size);
>                            ^
>     tools/testing/selftests/net/ipsec.c:1618:54: note: Calling function 'rtattr_pack',
>     4th argument 'NULL' value is 0
>     if (rtattr_pack(&req.nh, sizeof(req), XFRMA_IF_ID, NULL, 0)) {
>                                                        ^
>     tools/testing/selftests/net/ipsec.c:230:25: note: Null pointer dereference
>     memcpy(RTA_DATA(attr), payload, size);
>                            ^
> Fixes: 70bfdf62e93a ("selftests/net/ipsec: Add test for xfrm_spdattr_type_t")

Your Sign-off needs to be right after fixes.

> ---
> V2: Modify description.
>     Add code checking tools.
>     Separating family and given name in Signed-off-by line.
>     Modify code format.
>     Add fixes.
> ---

Please post v3 as a new thread (not in reply to).
-- 
pw-bot: cr