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author | Casey Schaufler <casey@schaufler-ca.com> | 2020-02-03 18:15:00 +0100 |
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committer | Casey Schaufler <casey@schaufler-ca.com> | 2020-02-05 23:16:27 +0100 |
commit | 87fbfffcc89b92a4281b0aa53bd06af714087889 (patch) | |
tree | 5d3f406243737483afeed91d15fb7740ec99197d /security/smack/smack_lsm.c | |
parent | Linux 5.5 (diff) | |
download | linux-87fbfffcc89b92a4281b0aa53bd06af714087889.tar.xz linux-87fbfffcc89b92a4281b0aa53bd06af714087889.zip |
broken ping to ipv6 linklocal addresses on debian buster
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>
security/smack/smack_lsm.c | 41 +++++++++++++++++++----------------------
1 file changed, 19 insertions(+), 22 deletions(-)
Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r-- | security/smack/smack_lsm.c | 41 |
1 files changed, 19 insertions, 22 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index ecea41ce919b..8bc7b04769a8 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2831,42 +2831,39 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 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; } |