[PATCH] net: netlink: fix error return code of netlink_proto_init()

[PATCH] net: netlink: fix error return code of netlink_proto_init()

[Jia-Ju Bai]

When kcalloc() returns NULL to nl_table, no error return code of
netlink_proto_init() is assigned.
To fix this bug, err is assigned with -ENOMEM in this case.

Fixes: fab2caf62ed0 ("[NETLINK]: Call panic if nl_table allocation fails")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 net/netlink/af_netlink.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index dd488938447f..9ab66cfb1037 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2880,8 +2880,10 @@ static int __init netlink_proto_init(void)
 	BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb));
 
 	nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
-	if (!nl_table)
+	if (!nl_table) {
+		err = -ENOMEM;
 		goto panic;
+	}
 
 	for (i = 0; i < MAX_LINKS; i++) {
 		if (rhashtable_init(&nl_table[i].hash,
-- 
2.17.1

Re: [PATCH] net: netlink: fix error return code of netlink_proto_init()

[Heiner Kallweit]

On 09.03.2021 09:33, Jia-Ju Bai wrote:
> When kcalloc() returns NULL to nl_table, no error return code of
> netlink_proto_init() is assigned.
> To fix this bug, err is assigned with -ENOMEM in this case.
> 

Didn't we talk enough about your incorrect patches yesterday?
This one is incorrect again. panic() never returns.
Stop sending patches until you understand the code you're changing!


> Fixes: fab2caf62ed0 ("[NETLINK]: Call panic if nl_table allocation fails")
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
>  net/netlink/af_netlink.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
> index dd488938447f..9ab66cfb1037 100644
> --- a/net/netlink/af_netlink.c
> +++ b/net/netlink/af_netlink.c
> @@ -2880,8 +2880,10 @@ static int __init netlink_proto_init(void)
>  	BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb));
>  
>  	nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
> -	if (!nl_table)
> +	if (!nl_table) {
> +		err = -ENOMEM;
>  		goto panic;
> +	}
>  
>  	for (i = 0; i < MAX_LINKS; i++) {
>  		if (rhashtable_init(&nl_table[i].hash,
> 

Re: [PATCH] net: netlink: fix error return code of netlink_proto_init()

[Jia-Ju Bai]

On 2021/3/9 16:47, Heiner Kallweit wrote:
> On 09.03.2021 09:33, Jia-Ju Bai wrote:
>> When kcalloc() returns NULL to nl_table, no error return code of
>> netlink_proto_init() is assigned.
>> To fix this bug, err is assigned with -ENOMEM in this case.
>>
> Didn't we talk enough about your incorrect patches yesterday?
> This one is incorrect again. panic() never returns.
> Stop sending patches until you understand the code you're changing!

Ah, sorry, I was too confident about this bug report...
Thanks for your reply.
Following your advice, now I am sending the patches only for the bug 
reports that I am confident about after careful code review.
Some of the patches have been applied, but some of them are still wrong, 
like this patch...
I am sorry for the false positives...


Best wishes,
Jia-Ju Bai