commit e3ebae48040b9ed3946e65dbc6a24e8f5e48ff6b Author: Nick Mathewson nickm@torproject.org Date: Mon Jun 5 10:09:39 2017 -0400

Fix undefined behavior in geoip_parse_entry().

Fixes bug 22490; bugfix on 6a241ff3ffe7dc1 in 0.2.4.6-alpha.

Found by teor using clang-5.0's AddressSanitizer stack-use-after-scope. --- changes/bug22490 | 3 +++ src/or/geoip.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/changes/bug22490 b/changes/bug22490 new file mode 100644 index 0000000..244dd50 --- /dev/null +++ b/changes/bug22490 @@ -0,0 +1,3 @@ + o Minor bugfixes (correctness): + - Avoid undefined behavior when parsing IPv6 entries from the geoip6 + file. Fixes bug 22490; bugfix on 0.2.4.6-alpha. diff --git a/src/or/geoip.c b/src/or/geoip.c index e2e98e8..4abd519 100644 --- a/src/or/geoip.c +++ b/src/or/geoip.c @@ -145,6 +145,7 @@ geoip_parse_entry(const char *line, sa_family_t family) if (*line == '#') return 0;

+ char buf[512]; if (family == AF_INET) { unsigned int low, high; if (tor_sscanf(line,"%u,%u,%2s", &low, &high, c) == 3 || @@ -155,7 +156,6 @@ geoip_parse_entry(const char *line, sa_family_t family) goto fail; country = c; } else { /* AF_INET6 */ - char buf[512]; char *low_str, *high_str; struct in6_addr low, high; char *strtok_state;