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authorPaolo Abeni <pabeni@redhat.com>2021-04-01 19:57:44 +0300
committerDavid S. Miller <davem@davemloft.net>2021-04-02 02:02:50 +0300
commit86581852d7710990d8af9dadfe9a661f0abf2114 (patch)
treee373efb54913fde9658b128757e4d89b3bbe8ef5 /net/mptcp
parenta0b96b4a62745397aee662670cfc2157bac03f55 (diff)
downloadlinux-86581852d7710990d8af9dadfe9a661f0abf2114.tar.xz
mptcp: forbit mcast-related sockopt on MPTCP sockets
Unrolling mcast state at msk dismantel time is bug prone, as syzkaller reported: ====================================================== WARNING: possible circular locking dependency detected 5.11.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor905/8822 is trying to acquire lock: ffffffff8d678fe8 (rtnl_mutex){+.+.}-{3:3}, at: ipv6_sock_mc_close+0xd7/0x110 net/ipv6/mcast.c:323 but task is already holding lock: ffff888024390120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1600 [inline] ffff888024390120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp6_release+0x57/0x130 net/mptcp/protocol.c:3507 which lock already depends on the new lock. Instead we can simply forbit any mcast-related setsockopt Fixes: 717e79c867ca5 ("mptcp: Add setsockopt()/getsockopt() socket operations") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/protocol.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1590b9d4cde2..e06cea0a3c54 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2878,6 +2878,48 @@ static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname,
return ret;
}
+static bool mptcp_unsupported(int level, int optname)
+{
+ if (level == SOL_IP) {
+ switch (optname) {
+ case IP_ADD_MEMBERSHIP:
+ case IP_ADD_SOURCE_MEMBERSHIP:
+ case IP_DROP_MEMBERSHIP:
+ case IP_DROP_SOURCE_MEMBERSHIP:
+ case IP_BLOCK_SOURCE:
+ case IP_UNBLOCK_SOURCE:
+ case MCAST_JOIN_GROUP:
+ case MCAST_LEAVE_GROUP:
+ case MCAST_JOIN_SOURCE_GROUP:
+ case MCAST_LEAVE_SOURCE_GROUP:
+ case MCAST_BLOCK_SOURCE:
+ case MCAST_UNBLOCK_SOURCE:
+ case MCAST_MSFILTER:
+ return true;
+ }
+ return false;
+ }
+ if (level == SOL_IPV6) {
+ switch (optname) {
+ case IPV6_ADDRFORM:
+ case IPV6_ADD_MEMBERSHIP:
+ case IPV6_DROP_MEMBERSHIP:
+ case IPV6_JOIN_ANYCAST:
+ case IPV6_LEAVE_ANYCAST:
+ case MCAST_JOIN_GROUP:
+ case MCAST_LEAVE_GROUP:
+ case MCAST_JOIN_SOURCE_GROUP:
+ case MCAST_LEAVE_SOURCE_GROUP:
+ case MCAST_BLOCK_SOURCE:
+ case MCAST_UNBLOCK_SOURCE:
+ case MCAST_MSFILTER:
+ return true;
+ }
+ return false;
+ }
+ return false;
+}
+
static int mptcp_setsockopt(struct sock *sk, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
@@ -2886,6 +2928,9 @@ static int mptcp_setsockopt(struct sock *sk, int level, int optname,
pr_debug("msk=%p", msk);
+ if (mptcp_unsupported(level, optname))
+ return -ENOPROTOOPT;
+
if (level == SOL_SOCKET)
return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen);