From 0d60d8df6f493bb46bf5db40d39dd60a1bafdd4e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 23 Feb 2024 12:32:08 +0000 Subject: dpll: rely on rcu for netdev_dpll_pin() This fixes a possible UAF in if_nlmsg_size(), which can run without RTNL. Add rcu protection to "struct dpll_pin" Move netdev_dpll_pin() from netdevice.h to dpll.h to decrease name pollution. Note: This looks possible to no longer acquire RTNL in netdev_dpll_pin_assign() later in net-next. v2: do not force rcu_read_lock() in rtnl_dpll_pin_size() (Jiri Pirko) Fixes: 5f1842692880 ("netdev: expose DPLL pin handle for netdevice") Signed-off-by: Eric Dumazet Cc: Arkadiusz Kubalewski Cc: Vadim Fedorenko Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20240223123208.3543319-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 73a021973007..0230391c78f7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9078,7 +9078,7 @@ static void netdev_dpll_pin_assign(struct net_device *dev, struct dpll_pin *dpll { #if IS_ENABLED(CONFIG_DPLL) rtnl_lock(); - dev->dpll_pin = dpll_pin; + rcu_assign_pointer(dev->dpll_pin, dpll_pin); rtnl_unlock(); #endif } -- cgit From 743ad091fb46e622f1b690385bb15e3cd3daf874 Mon Sep 17 00:00:00 2001 From: Lin Ma Date: Tue, 27 Feb 2024 20:11:28 +0800 Subject: rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic in the function `rtnl_bridge_setlink` to enable the loop to also check the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment removed the `break` statement and led to an error logic of the flags writing back at the end of this function. if (have_flags) memcpy(nla_data(attr), &flags, sizeof(flags)); // attr should point to IFLA_BRIDGE_FLAGS NLA !!! Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS. However, this is not necessarily true fow now as the updated loop will let the attr point to the last NLA, even an invalid NLA which could cause overflow writes. This patch introduces a new variable `br_flag` to save the NLA pointer that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned error logic. Fixes: d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length") Signed-off-by: Lin Ma Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20240227121128.608110-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski --- net/core/rtnetlink.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'net/core') diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9c4f427f3a50..ae86f751efc3 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -5169,10 +5169,9 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, struct net *net = sock_net(skb->sk); struct ifinfomsg *ifm; struct net_device *dev; - struct nlattr *br_spec, *attr = NULL; + struct nlattr *br_spec, *attr, *br_flags_attr = NULL; int rem, err = -EOPNOTSUPP; u16 flags = 0; - bool have_flags = false; if (nlmsg_len(nlh) < sizeof(*ifm)) return -EINVAL; @@ -5190,11 +5189,11 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC); if (br_spec) { nla_for_each_nested(attr, br_spec, rem) { - if (nla_type(attr) == IFLA_BRIDGE_FLAGS && !have_flags) { + if (nla_type(attr) == IFLA_BRIDGE_FLAGS && !br_flags_attr) { if (nla_len(attr) < sizeof(flags)) return -EINVAL; - have_flags = true; + br_flags_attr = attr; flags = nla_get_u16(attr); } @@ -5238,8 +5237,8 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, } } - if (have_flags) - memcpy(nla_data(attr), &flags, sizeof(flags)); + if (br_flags_attr) + memcpy(nla_data(br_flags_attr), &flags, sizeof(flags)); out: return err; } -- cgit