6.6-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 58a4ff5d77b187086eb12d41d613749420947f19 ]
route_dumpit() already relies on RCU, RTNL is not needed.
Also change return value at the end of a dump. This allows NLMSG_DONE to be appended to the current skb at the end of a dump, saving a couple of recvmsg() system calls.
Signed-off-by: Eric Dumazet edumazet@google.com Cc: Remi Denis-Courmont courmisch@gmail.com Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/20240507121748.416287-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: b5e837c86041 ("phonet: Handle error of rtnl_register_module().") Signed-off-by: Sasha Levin sashal@kernel.org --- net/phonet/pn_netlink.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c index dd4c7e9a634fb..7008d402499d5 100644 --- a/net/phonet/pn_netlink.c +++ b/net/phonet/pn_netlink.c @@ -178,7 +178,7 @@ static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst, rtm->rtm_type = RTN_UNICAST; rtm->rtm_flags = 0; if (nla_put_u8(skb, RTA_DST, dst) || - nla_put_u32(skb, RTA_OIF, dev->ifindex)) + nla_put_u32(skb, RTA_OIF, READ_ONCE(dev->ifindex))) goto nla_put_failure; nlmsg_end(skb, nlh); return 0; @@ -263,6 +263,7 @@ static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); + int err = 0; u8 addr;
rcu_read_lock(); @@ -272,16 +273,16 @@ static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb) if (!dev) continue;
- if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, RTM_NEWROUTE) < 0) - goto out; + err = fill_route(skb, dev, addr << 2, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, RTM_NEWROUTE); + if (err < 0) + break; } - -out: rcu_read_unlock(); cb->args[0] = addr;
- return skb->len; + return err; }
int __init phonet_netlink_register(void) @@ -301,6 +302,6 @@ int __init phonet_netlink_register(void) rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_DELROUTE, route_doit, NULL, 0); rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_GETROUTE, - NULL, route_dumpit, 0); + NULL, route_dumpit, RTNL_FLAG_DUMP_UNLOCKED); return 0; }