[PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[Dan Carpenter]

The nla_len() is less than or equal to 16.  If it's less than 16 then
end of the "gid" buffer is uninitialized.

Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
I just spotted this in review.  I think it's a bug but I'm not 100%.

 drivers/infiniband/core/addr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index 0abce004a959..a037ba4424bf 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -98,7 +98,7 @@ static inline bool ib_nl_is_good_ip_resp(const struct nlmsghdr *nlh)
 static void ib_nl_process_good_ip_rsep(const struct nlmsghdr *nlh)
 {
 	const struct nlattr *head, *curr;
-	union ib_gid gid;
+	union ib_gid gid = {};
 	struct addr_req *req;
 	int len, rem;
 	int found = 0;
-- 
2.30.2

Re: [PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[Leon Romanovsky]

On Fri, Apr 02, 2021 at 02:47:23PM +0300, Dan Carpenter wrote:
> The nla_len() is less than or equal to 16.  If it's less than 16 then
> end of the "gid" buffer is uninitialized.
> 
> Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> I just spotted this in review.  I think it's a bug but I'm not 100%.

I tend to agree with you, that it is a bug.

LS_NLA_TYPE_DGID is declared as NLA_BINARY which doesn't complain if
data is less than declared ".len". However, the fix needs to be in
ib_nl_is_good_ip_resp(), it shouldn't return "true" if length not equal
to 16.

Thanks

Re: [PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[Mark Bloch]

On 4/4/21 1:33 PM, Leon Romanovsky wrote:
> On Fri, Apr 02, 2021 at 02:47:23PM +0300, Dan Carpenter wrote:
>> The nla_len() is less than or equal to 16.  If it's less than 16 then
>> end of the "gid" buffer is uninitialized.
>>
>> Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload")
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>> ---
>> I just spotted this in review.  I think it's a bug but I'm not 100%.
> 
> I tend to agree with you, that it is a bug.
> 
> LS_NLA_TYPE_DGID is declared as NLA_BINARY which doesn't complain if
> data is less than declared ".len". However, the fix needs to be in
> ib_nl_is_good_ip_resp(), it shouldn't return "true" if length not equal
> to 16.

What about just updating the policy? The bellow diff should work I believe.

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index 0abce004a959..65e3e7df8a4b 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -76,7 +76,9 @@ static struct workqueue_struct *addr_wq;
 
 static const struct nla_policy ib_nl_addr_policy[LS_NLA_TYPE_MAX] = {
        [LS_NLA_TYPE_DGID] = {.type = NLA_BINARY,
-               .len = sizeof(struct rdma_nla_ls_gid)},
+               .len = sizeof(struct rdma_nla_ls_gid),
+               .validation_type = NLA_VALIDATE_MIN,
+               .min = sizeof(struct rdma_nla_ls_gid)},
 };
 
 static inline bool ib_nl_is_good_ip_resp(const struct nlmsghdr *nlh)

> 
> Thanks
> 

Mark

Re: [PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[Leon Romanovsky]

On Sun, Apr 04, 2021 at 04:13:17PM +0300, Mark Bloch wrote:
> On 4/4/21 1:33 PM, Leon Romanovsky wrote:
> > On Fri, Apr 02, 2021 at 02:47:23PM +0300, Dan Carpenter wrote:
> >> The nla_len() is less than or equal to 16.  If it's less than 16 then
> >> end of the "gid" buffer is uninitialized.
> >>
> >> Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload")
> >> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >> ---
> >> I just spotted this in review.  I think it's a bug but I'm not 100%.
> > 
> > I tend to agree with you, that it is a bug.
> > 
> > LS_NLA_TYPE_DGID is declared as NLA_BINARY which doesn't complain if
> > data is less than declared ".len". However, the fix needs to be in
> > ib_nl_is_good_ip_resp(), it shouldn't return "true" if length not equal
> > to 16.
> 
> What about just updating the policy? The bellow diff should work I believe.

I didn't know about ".validation_type", but yes this change will be enough.

> 
> diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
> index 0abce004a959..65e3e7df8a4b 100644
> --- a/drivers/infiniband/core/addr.c
> +++ b/drivers/infiniband/core/addr.c
> @@ -76,7 +76,9 @@ static struct workqueue_struct *addr_wq;
>  
>  static const struct nla_policy ib_nl_addr_policy[LS_NLA_TYPE_MAX] = {
>         [LS_NLA_TYPE_DGID] = {.type = NLA_BINARY,
> -               .len = sizeof(struct rdma_nla_ls_gid)},
> +               .len = sizeof(struct rdma_nla_ls_gid),
> +               .validation_type = NLA_VALIDATE_MIN,
> +               .min = sizeof(struct rdma_nla_ls_gid)},
>  };
>  
>  static inline bool ib_nl_is_good_ip_resp(const struct nlmsghdr *nlh)
> 
> > 
> > Thanks
> > 
> 
> Mark

Re: [PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[Dan Carpenter]

Could you send that and give me a reported-by?  I'm going AFK for a
week.

regards,
dan carpenter

Re: [PATCH] RDMA/addr: potential uninitialized variable in ib_nl_process_good_ip_rsep()

[Leon Romanovsky]

On Mon, Apr 05, 2021 at 08:41:41AM +0300, Dan Carpenter wrote:
> Could you send that and give me a reported-by?  I'm going AFK for a
> week.

Sure, we will handle it.

Thanks for the report.

> 
> regards,
> dan carpenter
>