From baf606d9c9b12517e47e0d1370e8aa9f7323f210 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Wed, 18 Mar 2015 14:50:42 -0300 Subject: [PATCH] ipv4,ipv6: grab rtnl before locking the socket There are some setsockopt operations in ipv4 and ipv6 that are grabbing rtnl after having grabbed the socket lock. Yet this makes it impossible to do operations that have to lock the socket when already within a rtnl protected scope, like ndo dev_open and dev_stop. We normally take coarse grained locks first but setsockopt inverted that. So this patch invert the lock logic for these operations and makes setsockopt grab rtnl if it will be needed prior to grabbing socket lock. Signed-off-by: Marcelo Ricardo Leitner Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv4/ip_sockglue.c | 31 +++++++++++++++++++++++++------ net/ipv6/ipv6_sockglue.c | 35 +++++++++++++++++++++++++++-------- 2 files changed, 52 insertions(+), 14 deletions(-) diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 5cd99271d3a6..5171709199f4 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -536,12 +536,25 @@ out: * Socket option code for IP. This is the end of the line after any * TCP,UDP etc options on an IP socket. */ +static bool setsockopt_needs_rtnl(int optname) +{ + switch (optname) { + case IP_ADD_MEMBERSHIP: + case IP_ADD_SOURCE_MEMBERSHIP: + case IP_DROP_MEMBERSHIP: + case MCAST_JOIN_GROUP: + case MCAST_LEAVE_GROUP: + return true; + } + return false; +} static int do_ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen) { struct inet_sock *inet = inet_sk(sk); int val = 0, err; + bool needs_rtnl = setsockopt_needs_rtnl(optname); switch (optname) { case IP_PKTINFO: @@ -584,6 +597,8 @@ static int do_ip_setsockopt(struct sock *sk, int level, return ip_mroute_setsockopt(sk, optname, optval, optlen); err = 0; + if (needs_rtnl) + rtnl_lock(); lock_sock(sk); switch (optname) { @@ -846,9 +861,9 @@ static int do_ip_setsockopt(struct sock *sk, int level, } if (optname == IP_ADD_MEMBERSHIP) - err = ip_mc_join_group(sk, &mreq); + err = __ip_mc_join_group(sk, &mreq); else - err = ip_mc_leave_group(sk, &mreq); + err = __ip_mc_leave_group(sk, &mreq); break; } case IP_MSFILTER: @@ -913,7 +928,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr; mreq.imr_address.s_addr = mreqs.imr_interface; mreq.imr_ifindex = 0; - err = ip_mc_join_group(sk, &mreq); + err = __ip_mc_join_group(sk, &mreq); if (err && err != -EADDRINUSE) break; omode = MCAST_INCLUDE; @@ -945,9 +960,9 @@ static int do_ip_setsockopt(struct sock *sk, int level, mreq.imr_ifindex = greq.gr_interface; if (optname == MCAST_JOIN_GROUP) - err = ip_mc_join_group(sk, &mreq); + err = __ip_mc_join_group(sk, &mreq); else - err = ip_mc_leave_group(sk, &mreq); + err = __ip_mc_leave_group(sk, &mreq); break; } case MCAST_JOIN_SOURCE_GROUP: @@ -990,7 +1005,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, mreq.imr_multiaddr = psin->sin_addr; mreq.imr_address.s_addr = 0; mreq.imr_ifindex = greqs.gsr_interface; - err = ip_mc_join_group(sk, &mreq); + err = __ip_mc_join_group(sk, &mreq); if (err && err != -EADDRINUSE) break; greqs.gsr_interface = mreq.imr_ifindex; @@ -1118,10 +1133,14 @@ mc_msf_out: break; } release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); return err; e_inval: release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); return -EINVAL; } diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 8d766d9100cb..f2b731df8d77 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -117,6 +117,18 @@ struct ipv6_txoptions *ipv6_update_options(struct sock *sk, return opt; } +static bool setsockopt_needs_rtnl(int optname) +{ + switch (optname) { + case IPV6_ADD_MEMBERSHIP: + case IPV6_DROP_MEMBERSHIP: + case MCAST_JOIN_GROUP: + case MCAST_LEAVE_GROUP: + return true; + } + return false; +} + static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen) { @@ -124,6 +136,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, struct net *net = sock_net(sk); int val, valbool; int retv = -ENOPROTOOPT; + bool needs_rtnl = setsockopt_needs_rtnl(optname); if (optval == NULL) val = 0; @@ -140,6 +153,8 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, if (ip6_mroute_opt(optname)) return ip6_mroute_setsockopt(sk, optname, optval, optlen); + if (needs_rtnl) + rtnl_lock(); lock_sock(sk); switch (optname) { @@ -582,9 +597,9 @@ done: break; if (optname == IPV6_ADD_MEMBERSHIP) - retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr); + retv = __ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr); else - retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr); + retv = __ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr); break; } case IPV6_JOIN_ANYCAST: @@ -623,11 +638,11 @@ done: } psin6 = (struct sockaddr_in6 *)&greq.gr_group; if (optname == MCAST_JOIN_GROUP) - retv = ipv6_sock_mc_join(sk, greq.gr_interface, - &psin6->sin6_addr); + retv = __ipv6_sock_mc_join(sk, greq.gr_interface, + &psin6->sin6_addr); else - retv = ipv6_sock_mc_drop(sk, greq.gr_interface, - &psin6->sin6_addr); + retv = __ipv6_sock_mc_drop(sk, greq.gr_interface, + &psin6->sin6_addr); break; } case MCAST_JOIN_SOURCE_GROUP: @@ -659,8 +674,8 @@ done: struct sockaddr_in6 *psin6; psin6 = (struct sockaddr_in6 *)&greqs.gsr_group; - retv = ipv6_sock_mc_join(sk, greqs.gsr_interface, - &psin6->sin6_addr); + retv = __ipv6_sock_mc_join(sk, greqs.gsr_interface, + &psin6->sin6_addr); /* prior join w/ different source is ok */ if (retv && retv != -EADDRINUSE) break; @@ -837,11 +852,15 @@ pref_skip_coa: } release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); return retv; e_inval: release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); return -EINVAL; } -- 2.30.2