From: Casey Schaufler casey@schaufler-ca.com
commit 87fbfffcc89b92a4281b0aa53bd06af714087889 upstream.
I am seeing ping failures to IPv6 linklocal addresses with Debian buster. Easiest example to reproduce is:
$ ping -c1 -w1 ff02::1%eth1 connect: Invalid argument
$ ping -c1 -w1 ff02::1%eth1 PING ff02::01%eth1(ff02::1%eth1) 56 data bytes 64 bytes from fe80::e0:f9ff:fe0c:37%eth1: icmp_seq=1 ttl=64 time=0.059 ms
git bisect traced the failure to commit b9ef5513c99b ("smack: Check address length before reading address family")
Arguably ping is being stupid since the buster version is not setting the address family properly (ping on stretch for example does):
$ strace -e connect ping6 -c1 -w1 ff02::1%eth1 connect(5, {sa_family=AF_UNSPEC, sa_data="\4\1\0\0\0\0\377\2\0\0\0\0\0\0\0\0\0\0\0\0\0\1\3\0\0\0"}, 28) = -1 EINVAL (Invalid argument)
but the command works fine on kernels prior to this commit, so this is breakage which goes against the Linux paradigm of "don't break userspace"
Cc: stable@vger.kernel.org Reported-by: David Ahern dsahern@gmail.com Suggested-by: Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp Signed-off-by: Casey Schaufler casey@schaufler-ca.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
security/smack/smack_lsm.c | 41 +++++++++++++++++++---------------------- security/smack/smack_lsm.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-)
--- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2831,42 +2831,39 @@ static int smack_socket_connect(struct s int addrlen) { int rc = 0; -#if IS_ENABLED(CONFIG_IPV6) - struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; -#endif -#ifdef SMACK_IPV6_SECMARK_LABELING - struct smack_known *rsp; - struct socket_smack *ssp; -#endif
if (sock->sk == NULL) return 0; - + if (sock->sk->sk_family != PF_INET && + (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6)) + return 0; + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return 0; + if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) { + struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; #ifdef SMACK_IPV6_SECMARK_LABELING - ssp = sock->sk->sk_security; + struct smack_known *rsp; #endif
- switch (sock->sk->sk_family) { - case PF_INET: - if (addrlen < sizeof(struct sockaddr_in) || - sap->sa_family != AF_INET) - return -EINVAL; - rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); - break; - case PF_INET6: - if (addrlen < SIN6_LEN_RFC2133 || sap->sa_family != AF_INET6) - return -EINVAL; + if (addrlen < SIN6_LEN_RFC2133) + return 0; #ifdef SMACK_IPV6_SECMARK_LABELING rsp = smack_ipv6host_label(sip); - if (rsp != NULL) + if (rsp != NULL) { + struct socket_smack *ssp = sock->sk->sk_security; + rc = smk_ipv6_check(ssp->smk_out, rsp, sip, - SMK_CONNECTING); + SMK_CONNECTING); + } #endif #ifdef SMACK_IPV6_PORT_LABELING rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); #endif - break; + return rc; } + if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in)) + return 0; + rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); return rc; }