From: Riccardo Paolo Bestetti pbl@bestov.io
commit b4a028c4d031c27704ad73b1195ca69a1206941e upstream.
Commit 8ff978b8b222 ("ipv4/raw: support binding to nonlocal addresses") introduced a helper function to fold duplicated validity checks of bind addresses into inet_addr_valid_or_nonlocal(). However, this caused an unintended regression in ping_check_bind_addr(), which previously would reject binding to multicast and broadcast addresses, but now these are both incorrectly allowed as reported in [1].
This patch restores the original check. A simple reordering is done to improve readability and make it evident that multicast and broadcast addresses should not be allowed. Also, add an early exit for INADDR_ANY which replaces lost behavior added by commit 0ce779a9f501 ("net: Avoid unnecessary inet_addr_type() call when addr is INADDR_ANY").
Furthermore, this patch introduces regression selftests to catch these specific cases.
[1] https://lore.kernel.org/netdev/CANP3RGdkAcDyAZoT1h8Gtuu0saq+eOrrTiWbxnOs+5zn...
Fixes: 8ff978b8b222 ("ipv4/raw: support binding to nonlocal addresses") Cc: Miaohe Lin linmiaohe@huawei.com Reported-by: Maciej Żenczykowski maze@google.com Signed-off-by: Carlos Llamas cmllamas@google.com Signed-off-by: Riccardo Paolo Bestetti pbl@bestov.io Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/ping.c | 10 ++++++--- tools/testing/selftests/net/fcnal-test.sh | 33 ++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 3 deletions(-)
--- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -319,12 +319,16 @@ static int ping_check_bind_addr(struct s pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
+ if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) + return 0; + tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id; chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
- if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), - addr->sin_addr.s_addr, - chk_addr_ret)) + if (chk_addr_ret == RTN_MULTICAST || + chk_addr_ret == RTN_BROADCAST || + (chk_addr_ret != RTN_LOCAL && + !inet_can_nonlocal_bind(net, isk))) return -EADDRNOTAVAIL;
#if IS_ENABLED(CONFIG_IPV6) --- a/tools/testing/selftests/net/fcnal-test.sh +++ b/tools/testing/selftests/net/fcnal-test.sh @@ -70,6 +70,10 @@ NSB_LO_IP6=2001:db8:2::2 NL_IP=172.17.1.1 NL_IP6=2001:db8:4::1
+# multicast and broadcast addresses +MCAST_IP=224.0.0.1 +BCAST_IP=255.255.255.255 + MD5_PW=abc123 MD5_WRONG_PW=abc1234
@@ -308,6 +312,9 @@ addr2str() 127.0.0.1) echo "loopback";; ::1) echo "IPv6 loopback";;
+ ${BCAST_IP}) echo "broadcast";; + ${MCAST_IP}) echo "multicast";; + ${NSA_IP}) echo "ns-A IP";; ${NSA_IP6}) echo "ns-A IPv6";; ${NSA_LO_IP}) echo "ns-A loopback IP";; @@ -1801,6 +1808,19 @@ ipv4_addr_bind_novrf() log_test_addr ${a} $? 0 "Raw socket bind to nonlocal address after device bind"
# + # check that ICMP sockets cannot bind to broadcast and multicast addresses + # + a=${BCAST_IP} + log_start + run_cmd nettest -s -R -P icmp -l ${a} -b + log_test_addr ${a} $? 1 "ICMP socket bind to broadcast address" + + a=${MCAST_IP} + log_start + run_cmd nettest -s -R -P icmp -f -l ${a} -b + log_test_addr ${a} $? 1 "ICMP socket bind to multicast address" + + # # tcp sockets # a=${NSA_IP} @@ -1858,6 +1878,19 @@ ipv4_addr_bind_vrf() log_test_addr ${a} $? 0 "Raw socket bind to nonlocal address after VRF bind"
# + # check that ICMP sockets cannot bind to broadcast and multicast addresses + # + a=${BCAST_IP} + log_start + run_cmd nettest -s -R -P icmp -l ${a} -I ${VRF} -b + log_test_addr ${a} $? 1 "ICMP socket bind to broadcast address after VRF bind" + + a=${MCAST_IP} + log_start + run_cmd nettest -s -R -P icmp -f -l ${a} -I ${VRF} -b + log_test_addr ${a} $? 1 "ICMP socket bind to multicast address after VRF bind" + + # # tcp sockets # for a in ${NSA_IP} ${VRF_IP}