commit d7ecdd645a68eeb7a5ab8c839479a05cc8a1e10e Author: Nick Mathewson nickm@torproject.org Date: Mon Dec 29 10:06:12 2014 -0500

Wipe all of the target space in tor_addr_{to,from}_sockaddr()

Otherwise we risk a subsequent memdup or memcpy copying uninitialized RAM into some other place that might eventually expose it. Let's make sure that doesn't happen.

Closes ticket 14041 --- changes/bug14041 | 5 +++++ src/common/address.c | 7 +++++-- 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/changes/bug14041 b/changes/bug14041 new file mode 100644 index 0000000..d3d6538 --- /dev/null +++ b/changes/bug14041 @@ -0,0 +1,5 @@ + o Minor features (security): + - Clear all memory targetted by tor_addr_{to,from}_sockaddr(), + not just the part that's used. This makes it harder for data leak + bugs to occur in the event of other programming failures. + Resolves ticket 14041. diff --git a/src/common/address.c b/src/common/address.c index b2431ee..267b4e3 100644 --- a/src/common/address.c +++ b/src/common/address.c @@ -89,13 +89,14 @@ tor_addr_to_sockaddr(const tor_addr_t *a, struct sockaddr *sa_out, socklen_t len) { + memset(sa_out, 0, len); + sa_family_t family = tor_addr_family(a); if (family == AF_INET) { struct sockaddr_in *sin; if (len < (int)sizeof(struct sockaddr_in)) return 0; sin = (struct sockaddr_in *)sa_out; - memset(sin, 0, sizeof(struct sockaddr_in)); #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN sin->sin_len = sizeof(struct sockaddr_in); #endif @@ -108,7 +109,6 @@ tor_addr_to_sockaddr(const tor_addr_t *a, if (len < (int)sizeof(struct sockaddr_in6)) return 0; sin6 = (struct sockaddr_in6 *)sa_out; - memset(sin6, 0, sizeof(struct sockaddr_in6)); #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_LEN sin6->sin6_len = sizeof(struct sockaddr_in6); #endif @@ -129,6 +129,9 @@ tor_addr_from_sockaddr(tor_addr_t *a, const struct sockaddr *sa, { tor_assert(a); tor_assert(sa); + + memset(a, 0, sizeof(*a)); + if (sa->sa_family == AF_INET) { struct sockaddr_in *sin = (struct sockaddr_in *) sa; tor_addr_from_ipv4n(a, sin->sin_addr.s_addr);