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| author | Di Zhu <zhudi21@huawei.com> | 2020-10-21 10:00:53 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-10-21 18:24:08 -0700 |
| commit | ebfe3c5183733f784264450a41646a482f964e5e (patch) | |
| tree | bd86f2a5823a70d137f0aec26d196d9f3fe0dfbf /net | |
| parent | 5403caf21648d739bf2b1266c33e34384c313379 (diff) | |
| download | linux-ebfe3c5183733f784264450a41646a482f964e5e.tar.bz2 | |
rtnetlink: fix data overflow in rtnl_calcit()
"ip addr show" command execute error when we have a physical
network card with a large number of VFs
The return value of if_nlmsg_size() in rtnl_calcit() will exceed
range of u16 data type when any network cards has a larger number of
VFs. rtnl_vfinfo_size() will significant increase needed dump size when
the value of num_vfs is larger.
Eventually we get a wrong value of min_ifinfo_dump_size because of overflow
which decides the memory size needed by netlink dump and netlink_dump()
will return -EMSGSIZE because of not enough memory was allocated.
So fix it by promoting min_dump_alloc data type to u32 to
avoid whole netlink message size overflow and it's also align
with the data type of struct netlink_callback{}.min_dump_alloc
which is assigned by return value of rtnl_calcit()
Signed-off-by: Di Zhu <zhudi21@huawei.com>
Link: https://lore.kernel.org/r/20201021020053.1401-1-zhudi21@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/rtnetlink.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 68e0682450c6..7d7223691783 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3709,13 +3709,13 @@ static int rtnl_dellinkprop(struct sk_buff *skb, struct nlmsghdr *nlh, return rtnl_linkprop(RTM_DELLINKPROP, skb, nlh, extack); } -static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) +static u32 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); - struct net_device *dev; + size_t min_ifinfo_dump_size = 0; struct nlattr *tb[IFLA_MAX+1]; u32 ext_filter_mask = 0; - u16 min_ifinfo_dump_size = 0; + struct net_device *dev; int hdrlen; /* Same kernel<->userspace interface hack as in rtnl_dump_ifinfo. */ @@ -3735,9 +3735,8 @@ static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) */ rcu_read_lock(); for_each_netdev_rcu(net, dev) { - min_ifinfo_dump_size = max_t(u16, min_ifinfo_dump_size, - if_nlmsg_size(dev, - ext_filter_mask)); + min_ifinfo_dump_size = max(min_ifinfo_dump_size, + if_nlmsg_size(dev, ext_filter_mask)); } rcu_read_unlock(); @@ -5494,7 +5493,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) { struct sock *rtnl; rtnl_dumpit_func dumpit; - u16 min_dump_alloc = 0; + u32 min_dump_alloc = 0; link = rtnl_get_link(family, type); if (!link || !link->dumpit) { |