From c12b32ba46bf959d884af7340c24f3981a34693f Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Tue, 26 Feb 2019 20:15:34 +0200 Subject: [PATCH] package/systemd: add upstream security fixes CVE-2019-6454: systemd (PID1) crash with specially crafted D-Bus message from unprivileged user Cc: Maxime Hadjinlian Cc: Yann E. MORIN Signed-off-by: Baruch Siach Signed-off-by: Peter Korsgaard --- ...age-paths-longer-than-BUS_PATH_SIZE_.patch | 53 +++++ ...ry-strings-to-hold-dbus-paths-on-the.patch | 194 ++++++++++++++++++ 2 files changed, 247 insertions(+) create mode 100644 package/systemd/0018-Refuse-dbus-message-paths-longer-than-BUS_PATH_SIZE_.patch create mode 100644 package/systemd/0019-Allocate-temporary-strings-to-hold-dbus-paths-on-the.patch diff --git a/package/systemd/0018-Refuse-dbus-message-paths-longer-than-BUS_PATH_SIZE_.patch b/package/systemd/0018-Refuse-dbus-message-paths-longer-than-BUS_PATH_SIZE_.patch new file mode 100644 index 0000000000..2de3b71b5c --- /dev/null +++ b/package/systemd/0018-Refuse-dbus-message-paths-longer-than-BUS_PATH_SIZE_.patch @@ -0,0 +1,53 @@ +From febef5e18558c114f4fb7c94f6c8ed3520c50cdf Mon Sep 17 00:00:00 2001 +From: Riccardo Schirone +Date: Mon, 4 Feb 2019 14:29:09 +0100 +Subject: [PATCH] Refuse dbus message paths longer than BUS_PATH_SIZE_MAX + limit. + +Even though the dbus specification does not enforce any length limit on the +path of a dbus message, having to analyze too long strings in PID1 may be +time-consuming and it may have security impacts. + +In any case, the limit is set so high that real-life applications should not +have a problem with it. + +(cherry picked from commit 61397a60d98e368a5720b37e83f3169e3eb511c4) +Signed-off-by: Baruch Siach +--- +Upstream status: commit 61397a60d98 + + src/libsystemd/sd-bus/bus-internal.c | 2 +- + src/libsystemd/sd-bus/bus-internal.h | 4 ++++ + 2 files changed, 5 insertions(+), 1 deletion(-) + +diff --git a/src/libsystemd/sd-bus/bus-internal.c b/src/libsystemd/sd-bus/bus-internal.c +index 40acae213381..598b7f110c73 100644 +--- a/src/libsystemd/sd-bus/bus-internal.c ++++ b/src/libsystemd/sd-bus/bus-internal.c +@@ -43,7 +43,7 @@ bool object_path_is_valid(const char *p) { + if (slash) + return false; + +- return true; ++ return (q - p) <= BUS_PATH_SIZE_MAX; + } + + char* object_path_startswith(const char *a, const char *b) { +diff --git a/src/libsystemd/sd-bus/bus-internal.h b/src/libsystemd/sd-bus/bus-internal.h +index f208b294d8f1..a8d61bf72a4e 100644 +--- a/src/libsystemd/sd-bus/bus-internal.h ++++ b/src/libsystemd/sd-bus/bus-internal.h +@@ -332,6 +332,10 @@ struct sd_bus { + + #define BUS_MESSAGE_SIZE_MAX (128*1024*1024) + #define BUS_AUTH_SIZE_MAX (64*1024) ++/* Note that the D-Bus specification states that bus paths shall have no size limit. We enforce here one ++ * anyway, since truly unbounded strings are a security problem. The limit we pick is relatively large however, ++ * to not clash unnecessarily with real-life applications. */ ++#define BUS_PATH_SIZE_MAX (64*1024) + + #define BUS_CONTAINER_DEPTH 128 + +-- +2.20.1 + diff --git a/package/systemd/0019-Allocate-temporary-strings-to-hold-dbus-paths-on-the.patch b/package/systemd/0019-Allocate-temporary-strings-to-hold-dbus-paths-on-the.patch new file mode 100644 index 0000000000..bd09e60207 --- /dev/null +++ b/package/systemd/0019-Allocate-temporary-strings-to-hold-dbus-paths-on-the.patch @@ -0,0 +1,194 @@ +From 9e3f5a77226d5320270c92df001f6c79be735af3 Mon Sep 17 00:00:00 2001 +From: Riccardo Schirone +Date: Mon, 4 Feb 2019 14:29:28 +0100 +Subject: [PATCH] Allocate temporary strings to hold dbus paths on the heap + +Paths are limited to BUS_PATH_SIZE_MAX but the maximum size is anyway too big +to be allocated on the stack, so let's switch to the heap where there is a +clear way to understand if the allocation fails. + +(cherry picked from commit f519a19bcd5afe674a9b8fc462cd77d8bad403c1) +[baruch: backport to v240] +Signed-off-by: Baruch Siach +--- +Upstream status: commit f519a19bcd5 + + src/libsystemd/sd-bus/bus-objects.c | 68 +++++++++++++++++++++++------ + 1 file changed, 54 insertions(+), 14 deletions(-) + +diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c +index d0538104ae25..54b977418e03 100644 +--- a/src/libsystemd/sd-bus/bus-objects.c ++++ b/src/libsystemd/sd-bus/bus-objects.c +@@ -1133,7 +1133,8 @@ static int object_manager_serialize_path_and_fallbacks( + const char *path, + sd_bus_error *error) { + +- char *prefix; ++ _cleanup_free_ char *prefix = NULL; ++ size_t pl; + int r; + + assert(bus); +@@ -1149,7 +1150,12 @@ static int object_manager_serialize_path_and_fallbacks( + return 0; + + /* Second, add fallback vtables registered for any of the prefixes */ +- prefix = alloca(strlen(path) + 1); ++ pl = strlen(path); ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; ++ + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { + r = object_manager_serialize_path(bus, reply, prefix, path, true, error); + if (r < 0) +@@ -1345,6 +1351,7 @@ static int object_find_and_run( + } + + int bus_process_object(sd_bus *bus, sd_bus_message *m) { ++ _cleanup_free_ char *prefix = NULL; + int r; + size_t pl; + bool found_object = false; +@@ -1369,9 +1376,12 @@ int bus_process_object(sd_bus *bus, sd_bus_message *m) { + assert(m->member); + + pl = strlen(m->path); +- do { +- char prefix[pl+1]; ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; + ++ do { + bus->nodes_modified = false; + + r = object_find_and_run(bus, m, m->path, false, &found_object); +@@ -1498,9 +1508,15 @@ static int bus_find_parent_object_manager(sd_bus *bus, struct node **out, const + + n = hashmap_get(bus->nodes, path); + if (!n) { +- char *prefix; ++ _cleanup_free_ char *prefix = NULL; ++ size_t pl; ++ ++ pl = strlen(path); ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; + +- prefix = alloca(strlen(path) + 1); + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { + n = hashmap_get(bus->nodes, prefix); + if (n) +@@ -2083,8 +2099,9 @@ _public_ int sd_bus_emit_properties_changed_strv( + const char *interface, + char **names) { + ++ _cleanup_free_ char *prefix = NULL; + bool found_interface = false; +- char *prefix; ++ size_t pl; + int r; + + assert_return(bus, -EINVAL); +@@ -2105,6 +2122,12 @@ _public_ int sd_bus_emit_properties_changed_strv( + + BUS_DONT_DESTROY(bus); + ++ pl = strlen(path); ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; ++ + do { + bus->nodes_modified = false; + +@@ -2114,7 +2137,6 @@ _public_ int sd_bus_emit_properties_changed_strv( + if (bus->nodes_modified) + continue; + +- prefix = alloca(strlen(path) + 1); + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { + r = emit_properties_changed_on_interface(bus, prefix, path, interface, true, &found_interface, names); + if (r != 0) +@@ -2246,7 +2268,8 @@ static int object_added_append_all_prefix( + + static int object_added_append_all(sd_bus *bus, sd_bus_message *m, const char *path) { + _cleanup_set_free_ Set *s = NULL; +- char *prefix; ++ _cleanup_free_ char *prefix = NULL; ++ size_t pl; + int r; + + assert(bus); +@@ -2291,7 +2314,12 @@ static int object_added_append_all(sd_bus *bus, sd_bus_message *m, const char *p + if (bus->nodes_modified) + return 0; + +- prefix = alloca(strlen(path) + 1); ++ pl = strlen(path); ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; ++ + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { + r = object_added_append_all_prefix(bus, m, s, prefix, path, true); + if (r < 0) +@@ -2430,7 +2458,8 @@ static int object_removed_append_all_prefix( + + static int object_removed_append_all(sd_bus *bus, sd_bus_message *m, const char *path) { + _cleanup_set_free_ Set *s = NULL; +- char *prefix; ++ _cleanup_free_ char *prefix = NULL; ++ size_t pl; + int r; + + assert(bus); +@@ -2462,7 +2491,12 @@ static int object_removed_append_all(sd_bus *bus, sd_bus_message *m, const char + if (bus->nodes_modified) + return 0; + +- prefix = alloca(strlen(path) + 1); ++ pl = strlen(path); ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; ++ + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { + r = object_removed_append_all_prefix(bus, m, s, prefix, path, true); + if (r < 0) +@@ -2612,7 +2646,8 @@ static int interfaces_added_append_one( + const char *path, + const char *interface) { + +- char *prefix; ++ _cleanup_free_ char *prefix = NULL; ++ size_t pl; + int r; + + assert(bus); +@@ -2626,7 +2661,12 @@ static int interfaces_added_append_one( + if (bus->nodes_modified) + return 0; + +- prefix = alloca(strlen(path) + 1); ++ pl = strlen(path); ++ assert(pl <= BUS_PATH_SIZE_MAX); ++ prefix = new(char, pl + 1); ++ if (!prefix) ++ return -ENOMEM; ++ + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { + r = interfaces_added_append_one_prefix(bus, m, prefix, path, interface, true); + if (r != 0) +-- +2.20.1 + -- 2.30.2