[PATCH V2] IB/sa: Restrict SA Netlink to admin users

[PATCH V2] IB/sa: Restrict SA Netlink to admin users

[ira.weiny-ral2JQCrhuEAvxtiuMwx3w]

From: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

The recently added SA Netlink service requires admin privileges to receive
kernel requests.  This is only partially sufficient to protect the kernel from
malicious users.  This patch fixes two issues.

	1) Path responses from user space could be spoofed if the sequence
	   number was properly guessed.
	2) The set timeout request message could be issued by any user.

Ignore these messages if not submitted by an admin user.

Fixes: 6619209af36c ("IB/sa: Route SA pathrecord query through netlink")
Signed-off-by: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

---
Changes from V1:
	Use netlink_net_capable rather than ns_capable

Doug let me know if you would prefer that I get Kaike to squash this into the
original patch.

 drivers/infiniband/core/sa_query.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index 70ceec4df02a..6778644a6957 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -699,6 +699,12 @@ static int ib_nl_handle_set_timeout(struct sk_buff *skb,
 	struct nlattr *tb[LS_NLA_TYPE_MAX + 1];
 	int ret;
 
+	if (!netlink_net_capable(skb, CAP_NET_ADMIN)) {
+		pr_warn_ratelimited("SA netlink: invalid perm for set timeout: `%s'.\n",
+				    current->comm);
+		return -EPERM;
+	}
+
 	ret = nla_parse(tb, LS_NLA_TYPE_MAX, nlmsg_data(nlh), nlmsg_len(nlh),
 			NULL);
 	attr = (const struct nlattr *)tb[LS_NLA_TYPE_TIMEOUT];
@@ -706,6 +712,9 @@ static int ib_nl_handle_set_timeout(struct sk_buff *skb,
 		goto settimeout_out;
 
 	timeout = *(int *) nla_data(attr);
+
+	pr_info("SA netlink: timeout: %d\n", timeout);
+
 	if (timeout < IB_SA_LOCAL_SVC_TIMEOUT_MIN)
 		timeout = IB_SA_LOCAL_SVC_TIMEOUT_MIN;
 	if (timeout > IB_SA_LOCAL_SVC_TIMEOUT_MAX)
@@ -754,6 +763,12 @@ static int ib_nl_handle_resolve_resp(struct sk_buff *skb,
 	int found = 0;
 	int ret;
 
+	if (!netlink_net_capable(skb, CAP_NET_ADMIN)) {
+		pr_warn_ratelimited("SA netlink: invalid perm for response: `%s'.\n",
+				    current->comm);
+		return -EPERM;
+	}
+
 	spin_lock_irqsave(&ib_nl_request_lock, flags);
 	list_for_each_entry(query, &ib_nl_request_list, list) {
 		/*
@@ -770,6 +785,7 @@ static int ib_nl_handle_resolve_resp(struct sk_buff *skb,
 
 	if (!found) {
 		spin_unlock_irqrestore(&ib_nl_request_lock, flags);
+		pr_err_ratelimited("SA netlink: got unmatched response\n");
 		goto resp_out;
 	}
 
-- 
1.8.2

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Re: [PATCH V2] IB/sa: Restrict SA Netlink to admin users

[ira.weiny]

On Mon, Aug 10, 2015 at 10:46:55PM -0400, ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote:
> From: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> 
> The recently added SA Netlink service requires admin privileges to receive
> kernel requests.  This is only partially sufficient to protect the kernel from
> malicious users.  This patch fixes two issues.
> 
> 	1) Path responses from user space could be spoofed if the sequence
> 	   number was properly guessed.
> 	2) The set timeout request message could be issued by any user.
> 
> Ignore these messages if not submitted by an admin user.
> 
> Fixes: 6619209af36c ("IB/sa: Route SA pathrecord query through netlink")
> Signed-off-by: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> 
> ---
> Changes from V1:
> 	Use netlink_net_capable rather than ns_capable

Doug,

As per the thread with the V1 patch we are looking to merge this into a v9 of
Kaikes series once we do some more testing with the netlink_bind and
namespaces.

So you can safely ignore both v1 and this patch.

Thanks,
Ira

> 
> Doug let me know if you would prefer that I get Kaike to squash this into the
> original patch.
> 
>  drivers/infiniband/core/sa_query.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
> index 70ceec4df02a..6778644a6957 100644
> --- a/drivers/infiniband/core/sa_query.c
> +++ b/drivers/infiniband/core/sa_query.c
> @@ -699,6 +699,12 @@ static int ib_nl_handle_set_timeout(struct sk_buff *skb,
>  	struct nlattr *tb[LS_NLA_TYPE_MAX + 1];
>  	int ret;
>  
> +	if (!netlink_net_capable(skb, CAP_NET_ADMIN)) {
> +		pr_warn_ratelimited("SA netlink: invalid perm for set timeout: `%s'.\n",
> +				    current->comm);
> +		return -EPERM;
> +	}
> +
>  	ret = nla_parse(tb, LS_NLA_TYPE_MAX, nlmsg_data(nlh), nlmsg_len(nlh),
>  			NULL);
>  	attr = (const struct nlattr *)tb[LS_NLA_TYPE_TIMEOUT];
> @@ -706,6 +712,9 @@ static int ib_nl_handle_set_timeout(struct sk_buff *skb,
>  		goto settimeout_out;
>  
>  	timeout = *(int *) nla_data(attr);
> +
> +	pr_info("SA netlink: timeout: %d\n", timeout);
> +
>  	if (timeout < IB_SA_LOCAL_SVC_TIMEOUT_MIN)
>  		timeout = IB_SA_LOCAL_SVC_TIMEOUT_MIN;
>  	if (timeout > IB_SA_LOCAL_SVC_TIMEOUT_MAX)
> @@ -754,6 +763,12 @@ static int ib_nl_handle_resolve_resp(struct sk_buff *skb,
>  	int found = 0;
>  	int ret;
>  
> +	if (!netlink_net_capable(skb, CAP_NET_ADMIN)) {
> +		pr_warn_ratelimited("SA netlink: invalid perm for response: `%s'.\n",
> +				    current->comm);
> +		return -EPERM;
> +	}
> +
>  	spin_lock_irqsave(&ib_nl_request_lock, flags);
>  	list_for_each_entry(query, &ib_nl_request_list, list) {
>  		/*
> @@ -770,6 +785,7 @@ static int ib_nl_handle_resolve_resp(struct sk_buff *skb,
>  
>  	if (!found) {
>  		spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +		pr_err_ratelimited("SA netlink: got unmatched response\n");
>  		goto resp_out;
>  	}
>  
> -- 
> 1.8.2
> 
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Re: [PATCH V2] IB/sa: Restrict SA Netlink to admin users

[Doug Ledford]

[-- Attachment #1: Type: text/plain, Size: 1288 bytes --]

On 08/12/2015 03:43 PM, ira.weiny wrote:
> On Mon, Aug 10, 2015 at 10:46:55PM -0400, ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote:
>> From: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>>
>> The recently added SA Netlink service requires admin privileges to receive
>> kernel requests.  This is only partially sufficient to protect the kernel from
>> malicious users.  This patch fixes two issues.
>>
>> 	1) Path responses from user space could be spoofed if the sequence
>> 	   number was properly guessed.
>> 	2) The set timeout request message could be issued by any user.
>>
>> Ignore these messages if not submitted by an admin user.
>>
>> Fixes: 6619209af36c ("IB/sa: Route SA pathrecord query through netlink")
>> Signed-off-by: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>>
>> ---
>> Changes from V1:
>> 	Use netlink_net_capable rather than ns_capable
> 
> Doug,
> 
> As per the thread with the V1 patch we are looking to merge this into a v9 of
> Kaikes series once we do some more testing with the netlink_bind and
> namespaces.
> 
> So you can safely ignore both v1 and this patch.

Ok.


-- 
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
              GPG KeyID: 0E572FDD



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