commit 837eefae26c209cb0204f376ed23f5b339e63424 Author: Tomas Hozza thozza@redhat.com Date: Tue Jan 22 17:40:49 2013 +0100
Fix for CVE-2013-0198 (checking of TCP connection interfaces)
Resolves: rhbz#901555 Signed-off-by: Tomas Hozza thozza@redhat.com
...aviour-for-TCP-queries-to-allowed-address.patch | 189 ++++++++++++++++++++ dnsmasq.spec | 10 +- 2 files changed, 198 insertions(+), 1 deletions(-) --- diff --git a/dnsmasq-2.65-Correct-behaviour-for-TCP-queries-to-allowed-address.patch b/dnsmasq-2.65-Correct-behaviour-for-TCP-queries-to-allowed-address.patch new file mode 100644 index 0000000..4b08fdc --- /dev/null +++ b/dnsmasq-2.65-Correct-behaviour-for-TCP-queries-to-allowed-address.patch @@ -0,0 +1,189 @@ +diff -up dnsmasq-2.65/src/dnsmasq.c.CVE-2013-0198 dnsmasq-2.65/src/dnsmasq.c +--- dnsmasq-2.65/src/dnsmasq.c.CVE-2013-0198 2012-12-14 12:48:26.000000000 +0100 ++++ dnsmasq-2.65/src/dnsmasq.c 2013-01-22 16:32:30.387640907 +0100 +@@ -1384,7 +1384,7 @@ static void check_dns_listeners(fd_set * + + if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) + { +- int confd; ++ int confd, client_ok = 1; + struct irec *iface = NULL; + pid_t p; + union mysockaddr tcp_addr; +@@ -1395,25 +1395,49 @@ static void check_dns_listeners(fd_set * + if (confd == -1 || + getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) + continue; +- +- if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) ++ ++ if (option_bool(OPT_NOWILD)) + iface = listener->iface; /* May be NULL */ +- else +- { +- /* Check for allowed interfaces when binding the wildcard address: +- we do this by looking for an interface with the same address as +- the local address of the TCP connection, then looking to see if that's +- an allowed interface. As a side effect, we get the netmask of the +- interface too, for localisation. */ +- +- /* interface may be new since startup */ +- if (enumerate_interfaces()) +- for (iface = daemon->interfaces; iface; iface = iface->next) +- if (sockaddr_isequal(&iface->addr, &tcp_addr)) +- break; +- } +- +- if (!iface && !(option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND))) ++ else ++ { ++ int if_index; ++ ++ /* In full wildcard mode, need to refresh interface list. ++ This happens automagically in CLEVERBIND */ ++ if (!option_bool(OPT_CLEVERBIND)) ++ enumerate_interfaces(); ++ ++ /* if we can find the arrival interface, check it's one that's allowed */ ++ if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0) ++ { ++ for (iface = daemon->interfaces; iface; iface = iface->next) ++ if (iface->index == if_index) ++ break; ++ ++ if (!iface) ++ client_ok = 0; ++ } ++ ++ if (option_bool(OPT_CLEVERBIND)) ++ iface = listener->iface; /* May be NULL */ ++ else ++ { ++ /* Check for allowed interfaces when binding the wildcard address: ++ we do this by looking for an interface with the same address as ++ the local address of the TCP connection, then looking to see if that's ++ an allowed interface. As a side effect, we get the netmask of the ++ interface too, for localisation. */ ++ ++ for (iface = daemon->interfaces; iface; iface = iface->next) ++ if (sockaddr_isequal(&iface->addr, &tcp_addr)) ++ break; ++ ++ if (!iface) ++ client_ok = 0; ++ } ++ } ++ ++ if (!client_ok) + { + shutdown(confd, SHUT_RDWR); + close(confd); +diff -up dnsmasq-2.65/src/dnsmasq.h.CVE-2013-0198 dnsmasq-2.65/src/dnsmasq.h +--- dnsmasq-2.65/src/dnsmasq.h.CVE-2013-0198 2012-12-14 12:48:26.000000000 +0100 ++++ dnsmasq-2.65/src/dnsmasq.h 2013-01-22 16:32:30.387640907 +0100 +@@ -412,7 +412,7 @@ struct server { + struct irec { + union mysockaddr addr; + struct in_addr netmask; /* only valid for IPv4 */ +- int tftp_ok, dhcp_ok, mtu, done, dad; ++ int tftp_ok, dhcp_ok, mtu, done, dad, index; + char *name; + struct irec *next; + }; +@@ -955,6 +955,7 @@ void create_bound_listeners(int die); + int is_dad_listeners(void); + int iface_check(int family, struct all_addr *addr, char *name); + int fix_fd(int fd); ++int tcp_interface(int fd, int af); + struct in_addr get_ifaddr(char *intr); + #ifdef HAVE_IPV6 + int set_ipv6pktinfo(int fd); +diff -up dnsmasq-2.65/src/network.c.CVE-2013-0198 dnsmasq-2.65/src/network.c +--- dnsmasq-2.65/src/network.c.CVE-2013-0198 2012-12-14 12:48:26.000000000 +0100 ++++ dnsmasq-2.65/src/network.c 2013-01-22 17:33:00.349128334 +0100 +@@ -239,6 +239,7 @@ static int iface_allowed(struct irec **i + iface->mtu = mtu; + iface->dad = dad; + iface->done = 0; ++ iface->index = if_index; + if ((iface->name = whine_malloc(strlen(ifr.ifr_name)+1))) + { + strcpy(iface->name, ifr.ifr_name); +@@ -420,6 +421,77 @@ int set_ipv6pktinfo(int fd) + return 0; + } + #endif ++ ++ ++/* Find the interface on which a TCP connection arrived, if possible, or zero otherwise. */ ++int tcp_interface(int fd, int af) ++{ ++ int if_index = 0; ++ ++#ifdef HAVE_LINUX_NETWORK ++ int opt = 1; ++ struct cmsghdr *cmptr; ++ struct msghdr msg; ++ ++ /* use mshdr do that the CMSDG_* macros are available */ ++ msg.msg_control = daemon->packet; ++ msg.msg_controllen = daemon->packet_buff_sz; ++ ++ /* we overwrote the buffer... */ ++ daemon->srv_save = NULL; ++ ++ if (af == AF_INET) ++ { ++ if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt)) != -1 && ++ getsockopt(fd, IPPROTO_IP, IP_PKTOPTIONS, msg.msg_control, (socklen_t *)&msg.msg_controllen) != -1) ++ for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) ++ if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO) ++ { ++ union { ++ unsigned char *c; ++ struct in_pktinfo *p; ++ } p; ++ ++ p.c = CMSG_DATA(cmptr); ++ if_index = p.p->ipi_ifindex; ++ } ++ } ++#ifdef HAVE_IPV6 ++ else ++ { ++ /* Only the RFC-2292 API has the ability to find the interface for TCP connections, ++ it was removed in RFC-3542 !!!! ++ ++ Fortunately, Linux kept the 2292 ABI when it moved to 3542. The following code always ++ uses the old ABI, and should work with pre- and post-3542 kernel headers */ ++ ++#ifdef IPV6_2292PKTOPTIONS ++# define PKTOPTIONS IPV6_2292PKTOPTIONS ++#else ++# define PKTOPTIONS IPV6_PKTOPTIONS ++#endif ++ ++ if (set_ipv6pktinfo(fd) && ++ getsockopt(fd, IPPROTO_IPV6, PKTOPTIONS, msg.msg_control, (socklen_t *)&msg.msg_controllen) != -1) ++ { ++ for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) ++ if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo) ++ { ++ union { ++ unsigned char *c; ++ struct in6_pktinfo *p; ++ } p; ++ p.c = CMSG_DATA(cmptr); ++ ++ if_index = p.p->ipi6_ifindex; ++ } ++ } ++ } ++#endif /* IPV6 */ ++#endif /* Linux */ ++ ++ return if_index; ++} + + static struct listener *create_listeners(union mysockaddr *addr, int do_tftp, int dienow) + { diff --git a/dnsmasq.spec b/dnsmasq.spec index 40cc1b8..72a8be9 100644 --- a/dnsmasq.spec +++ b/dnsmasq.spec @@ -11,7 +11,7 @@
Name: dnsmasq Version: 2.65 -Release: 1%{?extraversion}%{?dist} +Release: 2%{?extraversion}%{?dist} Summary: A lightweight DHCP/caching DNS server
Group: System Environment/Daemons @@ -20,6 +20,9 @@ URL: http://www.thekelleys.org.uk/dnsmasq/ Source0: http://www.thekelleys.org.uk/dnsmasq/%%7B?extrapath%7D%%7Bname%7D-%%7Bversio... Source1: %{name}.service
+# http://www.thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=22ce550e534694... +Patch0: %{name}-2.65-Correct-behaviour-for-TCP-queries-to-allowed-address.patch + BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
BuildRequires: dbus-devel @@ -53,6 +56,8 @@ query/remove a DHCP server's leases. %prep %setup -q -n %{name}-%{version}%{?extraversion}
+%patch0 -p1 -b .CVE-2013-0198 + # use /var/lib/dnsmasq instead of /var/lib/misc for file in dnsmasq.conf.example man/dnsmasq.8 man/es/dnsmasq.8 src/config.h; do sed -i 's|/var/lib/misc/dnsmasq.leases|/var/lib/dnsmasq/dnsmasq.leases|g' "$file" @@ -131,6 +136,9 @@ rm -rf $RPM_BUILD_ROOT %{_mandir}/man1/dhcp_*
%changelog +* Tue Jan 22 2013 Tomas Hozza thozza@redhat.com - 2.65-2 +- Fix for CVE-2013-0198 (checking of TCP connection interfaces) (#901555) + * Sat Dec 15 2012 Tomas Hozza thozza@redhat.com - 2.65-1 - new version 2.65
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Tomas Hozza