diff --git a/SOURCES/0001-evdev-strip-the-device-name-of-format-directives.patch b/SOURCES/0001-evdev-strip-the-device-name-of-format-directives.patch new file mode 100644 index 0000000..ef25b1b --- /dev/null +++ b/SOURCES/0001-evdev-strip-the-device-name-of-format-directives.patch @@ -0,0 +1,358 @@ +From d16e13645c11a4acdd6ed5f0bcbd486fcc2324f5 Mon Sep 17 00:00:00 2001 +From: Peter Hutterer +Date: Wed, 30 Mar 2022 09:25:22 +1000 +Subject: [PATCH] evdev: strip the device name of format directives +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +This fixes a format string vulnerabilty. + +evdev_log_message() composes a format string consisting of a fixed +prefix (including the rendered device name) and the passed-in format +buffer. This format string is then passed with the arguments to the +actual log handler, which usually and eventually ends up being printf. + +If the device name contains a printf-style format directive, these ended +up in the format string and thus get interpreted correctly, e.g. for a +device "Foo%sBar" the log message vs printf invocation ends up being: + evdev_log_message(device, "some message %s", "some argument"); + printf("event9 - Foo%sBar: some message %s", "some argument"); + +This can enable an attacker to execute malicious code with the +privileges of the process using libinput. + +To exploit this, an attacker needs to be able to create a kernel device +with a malicious name, e.g. through /dev/uinput or a Bluetooth device. + +To fix this, convert any potential format directives in the device name +by duplicating percentages. + +Pre-rendering the device to avoid the issue altogether would be nicer +but the current log level hooks do not easily allow for this. The device +name is the only user-controlled part of the format string. + +A second potential issue is the sysname of the device which is also +sanitized. + +This issue was found by Albin Eldstål-Ahrens and Benjamin Svensson from +Assured AB, and independently by Lukas Lamster. + +Fixes #752 + +Signed-off-by: Peter Hutterer +(cherry picked from commit a423d7d3269dc32a87384f79e29bb5ac021c83d1) +--- + meson.build | 1 + + src/evdev.c | 31 +++++++++++------ + src/evdev.h | 6 ++-- + src/util-strings.h | 30 ++++++++++++++++ + test/litest-device-format-string.c | 56 ++++++++++++++++++++++++++++++ + test/litest.h | 1 + + test/test-utils.c | 26 ++++++++++++++ + 7 files changed, 139 insertions(+), 12 deletions(-) + create mode 100644 test/litest-device-format-string.c + +diff --git a/meson.build b/meson.build +index 040e3f1f..05e405fe 100644 +--- a/meson.build ++++ b/meson.build +@@ -776,6 +776,7 @@ if get_option('tests') + 'test/litest-device-dell-canvas-totem-touch.c', + 'test/litest-device-elantech-touchpad.c', + 'test/litest-device-elan-tablet.c', ++ 'test/litest-device-format-string.c', + 'test/litest-device-generic-singletouch.c', + 'test/litest-device-gpio-keys.c', + 'test/litest-device-huion-pentablet.c', +diff --git a/src/evdev.c b/src/evdev.c +index 44d01711..3f674ba2 100644 +--- a/src/evdev.c ++++ b/src/evdev.c +@@ -2218,19 +2218,19 @@ evdev_device_create(struct libinput_seat *seat, + struct libinput *libinput = seat->libinput; + struct evdev_device *device = NULL; + int rc; +- int fd; ++ int fd = -1; + int unhandled_device = 0; + const char *devnode = udev_device_get_devnode(udev_device); +- const char *sysname = udev_device_get_sysname(udev_device); ++ char *sysname = str_sanitize(udev_device_get_sysname(udev_device)); + + if (!devnode) { + log_info(libinput, "%s: no device node associated\n", sysname); +- return NULL; ++ goto err; + } + + if (udev_device_should_be_ignored(udev_device)) { + log_debug(libinput, "%s: device is ignored\n", sysname); +- return NULL; ++ goto err; + } + + /* Use non-blocking mode so that we can loop on read on +@@ -2244,13 +2244,15 @@ evdev_device_create(struct libinput_seat *seat, + sysname, + devnode, + strerror(-fd)); +- return NULL; ++ goto err; + } + + if (!evdev_device_have_same_syspath(udev_device, fd)) + goto err; + + device = zalloc(sizeof *device); ++ device->sysname = sysname; ++ sysname = NULL; + + libinput_device_init(&device->base, seat); + libinput_seat_ref(seat); +@@ -2273,6 +2275,9 @@ evdev_device_create(struct libinput_seat *seat, + device->dispatch = NULL; + device->fd = fd; + device->devname = libevdev_get_name(device->evdev); ++ /* the log_prefix_name is used as part of a printf format string and ++ * must not contain % directives, see evdev_log_msg */ ++ device->log_prefix_name = str_sanitize(device->devname); + device->scroll.threshold = 5.0; /* Default may be overridden */ + device->scroll.direction_lock_threshold = 5.0; /* Default may be overridden */ + device->scroll.direction = 0; +@@ -2313,12 +2318,16 @@ evdev_device_create(struct libinput_seat *seat, + return device; + + err: +- close_restricted(libinput, fd); +- if (device) { +- unhandled_device = device->seat_caps == 0; +- evdev_device_destroy(device); ++ if (fd >= 0) { ++ close_restricted(libinput, fd); ++ if (device) { ++ unhandled_device = device->seat_caps == 0; ++ evdev_device_destroy(device); ++ } + } + ++ free(sysname); ++ + return unhandled_device ? EVDEV_UNHANDLED_DEVICE : NULL; + } + +@@ -2331,7 +2340,7 @@ evdev_device_get_output(struct evdev_device *device) + const char * + evdev_device_get_sysname(struct evdev_device *device) + { +- return udev_device_get_sysname(device->udev_device); ++ return device->sysname; + } + + const char * +@@ -2909,6 +2918,8 @@ evdev_device_destroy(struct evdev_device *device) + if (device->base.group) + libinput_device_group_unref(device->base.group); + ++ free(device->log_prefix_name); ++ free(device->sysname); + free(device->output_name); + filter_destroy(device->pointer.filter); + libinput_timer_destroy(&device->scroll.timer); +diff --git a/src/evdev.h b/src/evdev.h +index b0b1b8c6..785ba9ae 100644 +--- a/src/evdev.h ++++ b/src/evdev.h +@@ -169,6 +169,8 @@ struct evdev_device { + struct udev_device *udev_device; + char *output_name; + const char *devname; ++ char *log_prefix_name; ++ char *sysname; + bool was_removed; + int fd; + enum evdev_device_seat_capability seat_caps; +@@ -770,7 +772,7 @@ evdev_log_msg(struct evdev_device *device, + sizeof(buf), + "%-7s - %s%s%s", + evdev_device_get_sysname(device), +- (priority > LIBINPUT_LOG_PRIORITY_DEBUG) ? device->devname : "", ++ (priority > LIBINPUT_LOG_PRIORITY_DEBUG) ? device->log_prefix_name : "", + (priority > LIBINPUT_LOG_PRIORITY_DEBUG) ? ": " : "", + format); + +@@ -805,7 +807,7 @@ evdev_log_msg_ratelimit(struct evdev_device *device, + sizeof(buf), + "%-7s - %s%s%s", + evdev_device_get_sysname(device), +- (priority > LIBINPUT_LOG_PRIORITY_DEBUG) ? device->devname : "", ++ (priority > LIBINPUT_LOG_PRIORITY_DEBUG) ? device->log_prefix_name : "", + (priority > LIBINPUT_LOG_PRIORITY_DEBUG) ? ": " : "", + format); + +diff --git a/src/util-strings.h b/src/util-strings.h +index 80e88aeb..5a0711d0 100644 +--- a/src/util-strings.h ++++ b/src/util-strings.h +@@ -43,6 +43,8 @@ + #include + #endif + ++#include "util-macros.h" ++ + #define streq(s1, s2) (strcmp((s1), (s2)) == 0) + #define strneq(s1, s2, n) (strncmp((s1), (s2), (n)) == 0) + +@@ -376,3 +378,31 @@ strstartswith(const char *str, const char *prefix) + + return prefixlen > 0 ? strneq(str, prefix, strlen(prefix)) : false; + } ++ ++/** ++ * Return a copy of str with all % converted to %% to make the string ++ * acceptable as printf format. ++ */ ++static inline char * ++str_sanitize(const char *str) ++{ ++ if (!str) ++ return NULL; ++ ++ if (!strchr(str, '%')) ++ return strdup(str); ++ ++ size_t slen = min(strlen(str), 512); ++ char *sanitized = zalloc(2 * slen + 1); ++ const char *src = str; ++ char *dst = sanitized; ++ ++ for (size_t i = 0; i < slen; i++) { ++ if (*src == '%') ++ *dst++ = '%'; ++ *dst++ = *src++; ++ } ++ *dst = '\0'; ++ ++ return sanitized; ++} +diff --git a/test/litest-device-format-string.c b/test/litest-device-format-string.c +new file mode 100644 +index 00000000..aed15db4 +--- /dev/null ++++ b/test/litest-device-format-string.c +@@ -0,0 +1,56 @@ ++ ++/* ++ * Copyright © 2013 Red Hat, Inc. ++ * ++ * Permission is hereby granted, free of charge, to any person obtaining a ++ * copy of this software and associated documentation files (the "Software"), ++ * to deal in the Software without restriction, including without limitation ++ * the rights to use, copy, modify, merge, publish, distribute, sublicense, ++ * and/or sell copies of the Software, and to permit persons to whom the ++ * Software is furnished to do so, subject to the following conditions: ++ * ++ * The above copyright notice and this permission notice (including the next ++ * paragraph) shall be included in all copies or substantial portions of the ++ * Software. ++ * ++ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR ++ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, ++ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL ++ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER ++ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING ++ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER ++ * DEALINGS IN THE SOFTWARE. ++ */ ++ ++#include "config.h" ++ ++#include "litest.h" ++#include "litest-int.h" ++ ++static struct input_id input_id = { ++ .bustype = 0x3, ++ .vendor = 0x0123, ++ .product = 0x0456, ++}; ++ ++static int events[] = { ++ EV_KEY, BTN_LEFT, ++ EV_KEY, BTN_RIGHT, ++ EV_KEY, BTN_MIDDLE, ++ EV_REL, REL_X, ++ EV_REL, REL_Y, ++ EV_REL, REL_WHEEL, ++ EV_REL, REL_WHEEL_HI_RES, ++ -1 , -1, ++}; ++ ++TEST_DEVICE("mouse-format-string", ++ .type = LITEST_MOUSE_FORMAT_STRING, ++ .features = LITEST_RELATIVE | LITEST_BUTTON | LITEST_WHEEL, ++ .interface = NULL, ++ ++ .name = "Evil %s %d %x Mouse %p %", ++ .id = &input_id, ++ .absinfo = NULL, ++ .events = events, ++) +diff --git a/test/litest.h b/test/litest.h +index 25dc9eed..8b6d1ea3 100644 +--- a/test/litest.h ++++ b/test/litest.h +@@ -307,6 +307,7 @@ enum litest_device_type { + LITEST_KEYBOARD_LOGITECH_MEDIA_KEYBOARD_ELITE, + LITEST_SONY_VAIO_KEYS, + LITEST_KEYBOARD_QUIRKED, ++ LITEST_MOUSE_FORMAT_STRING, + }; + + #define LITEST_DEVICELESS -2 +diff --git a/test/test-utils.c b/test/test-utils.c +index 5955f56e..aa239092 100644 +--- a/test/test-utils.c ++++ b/test/test-utils.c +@@ -1196,6 +1196,31 @@ START_TEST(strstartswith_test) + } + END_TEST + ++START_TEST(strsanitize_test) ++{ ++ struct strsanitize_test { ++ const char *string; ++ const char *expected; ++ } tests[] = { ++ { "foobar", "foobar" }, ++ { "", "" }, ++ { "%", "%%" }, ++ { "%%%%", "%%%%%%%%" }, ++ { "x %s", "x %%s" }, ++ { "x %", "x %%" }, ++ { "%sx", "%%sx" }, ++ { "%s%s", "%%s%%s" }, ++ { NULL, NULL }, ++ }; ++ ++ for (struct strsanitize_test *t = tests; t->string; t++) { ++ char *sanitized = str_sanitize(t->string); ++ ck_assert_str_eq(sanitized, t->expected); ++ free(sanitized); ++ } ++} ++END_TEST ++ + START_TEST(list_test_insert) + { + struct list_test { +@@ -1305,6 +1330,7 @@ litest_utils_suite(void) + tcase_add_test(tc, strstrip_test); + tcase_add_test(tc, strendswith_test); + tcase_add_test(tc, strstartswith_test); ++ tcase_add_test(tc, strsanitize_test); + tcase_add_test(tc, time_conversion); + tcase_add_test(tc, human_time); + +-- +2.36.0 + diff --git a/SPECS/libinput.spec b/SPECS/libinput.spec index a99df04..76c212c 100644 --- a/SPECS/libinput.spec +++ b/SPECS/libinput.spec @@ -5,7 +5,7 @@ Name: libinput Version: 1.16.3 -Release: 2%{?gitdate:.%{gitdate}git%{gitversion}}%{?dist} +Release: 3%{?gitdate:.%{gitdate}git%{gitversion}}%{?dist} Summary: Input device library License: MIT @@ -32,6 +32,9 @@ Patch008: 0004-quirks-add-AttrInputPropEnable-and-Disable.patch Patch009: 0005-tools-print-the-AttrEventCodeEnable-and-AttrInputPro.patch Patch010: 0006-quirks-add-quirk-for-Dell-Precision-7550-7750-touchp.patch +# CVE-2022-1215: format string vulnerability (#2076815) +Patch011: 0001-evdev-strip-the-device-name-of-format-directives.patch + BuildRequires: git-core BuildRequires: gcc gcc-c++ BuildRequires: meson @@ -159,6 +162,10 @@ rm $RPM_BUILD_ROOT/%{_mandir}/man1/libinput-measure-touchpad-size.1* %{_mandir}/man1/libinput-test-suite.1* %changelog +* Thu Apr 28 2022 Peter Hutterer - 1.16.3-3 +- Fix a format string vulnerability in the device name logging (#2076815) + CVE-2022-1215 + * Tue May 25 2021 Peter Hutterer 1.16.3-2 - Add support for AddrInputPropDisable (#1951885)