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Message-Id: <20200401161546.256704789@linuxfoundation.org>
Date: Wed, 1 Apr 2020 18:16:46 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Taehee Yoo <ap420073@...il.com>,
"David S. Miller" <davem@...emloft.net>
Subject: [PATCH 4.19 030/116] hsr: use rcu_read_lock() in hsr_get_node_{list/status}()
From: Taehee Yoo <ap420073@...il.com>
[ Upstream commit 173756b86803655d70af7732079b3aa935e6ab68 ]
hsr_get_node_{list/status}() are not under rtnl_lock() because
they are callback functions of generic netlink.
But they use __dev_get_by_index() without rtnl_lock().
So, it would use unsafe data.
In order to fix it, rcu_read_lock() and dev_get_by_index_rcu()
are used instead of __dev_get_by_index().
Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Taehee Yoo <ap420073@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
net/hsr/hsr_framereg.c | 10 ++--------
net/hsr/hsr_netlink.c | 43 +++++++++++++++++++++----------------------
2 files changed, 23 insertions(+), 30 deletions(-)
--- a/net/hsr/hsr_framereg.c
+++ b/net/hsr/hsr_framereg.c
@@ -466,13 +466,9 @@ int hsr_get_node_data(struct hsr_priv *h
struct hsr_port *port;
unsigned long tdiff;
-
- rcu_read_lock();
node = find_node_by_AddrA(&hsr->node_db, addr);
- if (!node) {
- rcu_read_unlock();
- return -ENOENT; /* No such entry */
- }
+ if (!node)
+ return -ENOENT;
ether_addr_copy(addr_b, node->MacAddressB);
@@ -507,7 +503,5 @@ int hsr_get_node_data(struct hsr_priv *h
*addr_b_ifindex = -1;
}
- rcu_read_unlock();
-
return 0;
}
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -259,17 +259,16 @@ static int hsr_get_node_status(struct sk
if (!na)
goto invalid;
- hsr_dev = __dev_get_by_index(genl_info_net(info),
- nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+ rcu_read_lock();
+ hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
+ nla_get_u32(info->attrs[HSR_A_IFINDEX]));
if (!hsr_dev)
- goto invalid;
+ goto rcu_unlock;
if (!is_hsr_master(hsr_dev))
- goto invalid;
-
+ goto rcu_unlock;
/* Send reply */
-
- skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+ skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb_out) {
res = -ENOMEM;
goto fail;
@@ -321,12 +320,10 @@ static int hsr_get_node_status(struct sk
res = nla_put_u16(skb_out, HSR_A_IF1_SEQ, hsr_node_if1_seq);
if (res < 0)
goto nla_put_failure;
- rcu_read_lock();
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
if (port)
res = nla_put_u32(skb_out, HSR_A_IF1_IFINDEX,
port->dev->ifindex);
- rcu_read_unlock();
if (res < 0)
goto nla_put_failure;
@@ -336,20 +333,22 @@ static int hsr_get_node_status(struct sk
res = nla_put_u16(skb_out, HSR_A_IF2_SEQ, hsr_node_if2_seq);
if (res < 0)
goto nla_put_failure;
- rcu_read_lock();
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
if (port)
res = nla_put_u32(skb_out, HSR_A_IF2_IFINDEX,
port->dev->ifindex);
- rcu_read_unlock();
if (res < 0)
goto nla_put_failure;
+ rcu_read_unlock();
+
genlmsg_end(skb_out, msg_head);
genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
return 0;
+rcu_unlock:
+ rcu_read_unlock();
invalid:
netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
return 0;
@@ -359,6 +358,7 @@ nla_put_failure:
/* Fall through */
fail:
+ rcu_read_unlock();
return res;
}
@@ -385,17 +385,16 @@ static int hsr_get_node_list(struct sk_b
if (!na)
goto invalid;
- hsr_dev = __dev_get_by_index(genl_info_net(info),
- nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+ rcu_read_lock();
+ hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
+ nla_get_u32(info->attrs[HSR_A_IFINDEX]));
if (!hsr_dev)
- goto invalid;
+ goto rcu_unlock;
if (!is_hsr_master(hsr_dev))
- goto invalid;
-
+ goto rcu_unlock;
/* Send reply */
-
- skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+ skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb_out) {
res = -ENOMEM;
goto fail;
@@ -415,14 +414,11 @@ static int hsr_get_node_list(struct sk_b
hsr = netdev_priv(hsr_dev);
- rcu_read_lock();
pos = hsr_get_next_node(hsr, NULL, addr);
while (pos) {
res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr);
- if (res < 0) {
- rcu_read_unlock();
+ if (res < 0)
goto nla_put_failure;
- }
pos = hsr_get_next_node(hsr, pos, addr);
}
rcu_read_unlock();
@@ -432,6 +428,8 @@ static int hsr_get_node_list(struct sk_b
return 0;
+rcu_unlock:
+ rcu_read_unlock();
invalid:
netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
return 0;
@@ -441,6 +439,7 @@ nla_put_failure:
/* Fall through */
fail:
+ rcu_read_unlock();
return res;
}
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