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ipv4: ping: fix bind address validity check 

Commit 8ff978b8b2 ("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 0ce779a9f5 ("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+cpyKg@mail.gmail.com/

Fixes: 8ff978b8b2 ("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>
This commit is contained in:
Riccardo Paolo Bestetti 2022-06-17 10:54:35 +02:00 committed by David S. Miller
parent 2b04495e21
commit b4a028c4d0
2 changed files with 40 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/ipv4/ping.c
View File

@ -319,12 +319,16 @@ static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
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)

33
tools/testing/selftests/net/fcnal-test.sh
View File

@ -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";;
@ -1800,6 +1807,19 @@ ipv4_addr_bind_novrf()
run_cmd nettest -s -R -P icmp -f -l ${a} -I ${NSA_DEV} -b
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
#
@ -1857,6 +1877,19 @@ ipv4_addr_bind_vrf()
run_cmd nettest -s -R -P icmp -f -l ${a} -I ${VRF} -b
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
#