From 5088d3b38775f8ac12d7f77636775b16059b67ef Mon Sep 17 00:00:00 2001 From: Jeff King Date: Tue, 22 Sep 2015 18:03:49 -0400 Subject: [PATCH] transport: refactor protocol whitelist code The current callers only want to die when their transport is prohibited. But future callers want to query the mechanism without dying. Let's break out a few query functions, and also save the results in a static list so we don't have to re-parse for each query. Based-on-a-patch-by: Blake Burkhart Signed-off-by: Jeff King Signed-off-by: Junio C Hamano Upstream-Status: Backport https://kernel.googlesource.com/pub/scm/git/git/+/5088d3b38775f8ac12d7f77636775b16059b67ef%5E%21/ CVE: CVE-2015-7545 patch #1 Signed-off-by: Armin Kuster --- transport.c | 38 ++++++++++++++++++++++++++++++-------- transport.h | 15 +++++++++++++-- 2 files changed, 43 insertions(+), 10 deletions(-) Index: git-2.3.0/transport.c =================================================================== --- git-2.3.0.orig/transport.c +++ git-2.3.0/transport.c @@ -907,18 +907,40 @@ static int external_specification_len(co return strchr(url, ':') - url; } -void transport_check_allowed(const char *type) +static const struct string_list *protocol_whitelist(void) { - struct string_list allowed = STRING_LIST_INIT_DUP; - const char *v = getenv("GIT_ALLOW_PROTOCOL"); + static int enabled = -1; + static struct string_list allowed = STRING_LIST_INIT_DUP; + + if (enabled < 0) { + const char *v = getenv("GIT_ALLOW_PROTOCOL"); + if (v) { + string_list_split(&allowed, v, ':', -1); + string_list_sort(&allowed); + enabled = 1; + } else { + enabled = 0; + } + } + + return enabled ? &allowed : NULL; +} - if (!v) - return; +int is_transport_allowed(const char *type) +{ + const struct string_list *allowed = protocol_whitelist(); + return !allowed || string_list_has_string(allowed, type); +} - string_list_split(&allowed, v, ':', -1); - if (!unsorted_string_list_has_string(&allowed, type)) +void transport_check_allowed(const char *type) +{ + if (!is_transport_allowed(type)) die("transport '%s' not allowed", type); - string_list_clear(&allowed, 0); +} + +int transport_restrict_protocols(void) +{ + return !!protocol_whitelist(); } struct transport *transport_get(struct remote *remote, const char *url) Index: git-2.3.0/transport.h =================================================================== --- git-2.3.0.orig/transport.h +++ git-2.3.0/transport.h @@ -133,12 +133,23 @@ struct transport { struct transport *transport_get(struct remote *, const char *); /* + * Check whether a transport is allowed by the environment. Type should + * generally be the URL scheme, as described in Documentation/git.txt + */ +int is_transport_allowed(const char *type); + +/* * Check whether a transport is allowed by the environment, - * and die otherwise. type should generally be the URL scheme, - * as described in Documentation/git.txt + * and die otherwise. */ void transport_check_allowed(const char *type); +/* + * Returns true if the user has attempted to turn on protocol + * restrictions at all. + */ +int transport_restrict_protocols(void); + /* Transport options which apply to git:// and scp-style URLs */ /* The program to use on the remote side to send a pack */