From: Wolfgang Bumiller <w.bumiller@proxmox.com>

Date: Wed, 13 Jan 2016 09:09:58 +0100

Subject: [PATCH] hmp: fix sendkey out of bounds write (CVE-2015-8619)

When processing 'sendkey' command, hmp_sendkey routine null

terminates the 'keyname_buf' array. This results in an OOB

write issue, if 'keyname_len' was to fall outside of

'keyname_buf' array.

Since the keyname's length is known the keyname_buf can be

removed altogether by adding a length parameter to

index_from_key() and using it for the error output as well.

Reported-by: Ling Liu <liuling-it@360.cn>

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

Message-Id: <20160113080958.GA18934@olga>

[Comparison with "<" dumbed down, test for junk after strtoul()

tweaked]

Signed-off-by: Markus Armbruster <armbru@redhat.com>

(cherry picked from commit 64ffbe04eaafebf4045a3ace52a360c14959d196)

---

 hmp.c                | 18 ++++++++----------

 include/ui/console.h |  2 +-

 ui/input-legacy.c    |  5 +++--

 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/hmp.c b/hmp.c

index 2140605..1904203 100644

--- a/hmp.c

+++ b/hmp.c

@@ -1734,21 +1734,18 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict)

     int has_hold_time = qdict_haskey(qdict, "hold-time");

     int hold_time = qdict_get_try_int(qdict, "hold-time", -1);

     Error *err = NULL;

-    char keyname_buf[16];

     char *separator;

     int keyname_len;

     while (1) {

         separator = strchr(keys, '-');

         keyname_len = separator ? separator - keys : strlen(keys);

-        pstrcpy(keyname_buf, sizeof(keyname_buf), keys);

         /* Be compatible with old interface, convert user inputted "<" */

-        if (!strncmp(keyname_buf, "<", 1) && keyname_len == 1) {

-            pstrcpy(keyname_buf, sizeof(keyname_buf), "less");

+        if (keys[0] == '<' && keyname_len == 1) {

+            keys = "less";

             keyname_len = 4;

         }

-        keyname_buf[keyname_len] = 0;

         keylist = g_malloc0(sizeof(*keylist));

         keylist->value = g_malloc0(sizeof(*keylist->value));

@@ -1761,16 +1758,17 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict)

         }

         tmp = keylist;

-        if (strstart(keyname_buf, "0x", NULL)) {

+        if (strstart(keys, "0x", NULL)) {

             char *endp;

-            int value = strtoul(keyname_buf, &endp, 0);

-            if (*endp != '\0') {

+            int value = strtoul(keys, &endp, 0);

+            assert(endp <= keys + keyname_len);

+            if (endp != keys + keyname_len) {

                 goto err_out;

             }

             keylist->value->type = KEY_VALUE_KIND_NUMBER;

             keylist->value->u.number = value;

         } else {

-            int idx = index_from_key(keyname_buf);

+            int idx = index_from_key(keys, keyname_len);

             if (idx == Q_KEY_CODE_MAX) {

                 goto err_out;

             }

@@ -1792,7 +1790,7 @@ out:

     return;

 err_out:

-    monitor_printf(mon, "invalid parameter: %s\n", keyname_buf);

+    monitor_printf(mon, "invalid parameter: %.*s\n", keyname_len, keys);

     goto out;

 }

diff --git a/include/ui/console.h b/include/ui/console.h

index c249db4..5739bdd 100644

--- a/include/ui/console.h

+++ b/include/ui/console.h

@@ -433,7 +433,7 @@ static inline int vnc_display_pw_expire(const char *id, time_t expires)

 void curses_display_init(DisplayState *ds, int full_screen);

 /* input.c */

-int index_from_key(const char *key);

+int index_from_key(const char *key, size_t key_length);

 /* gtk.c */

 void early_gtk_display_init(int opengl);

diff --git a/ui/input-legacy.c b/ui/input-legacy.c

index e0a39f0..3f28bbc 100644

--- a/ui/input-legacy.c

+++ b/ui/input-legacy.c

@@ -57,12 +57,13 @@ struct QEMUPutLEDEntry {

 static QTAILQ_HEAD(, QEMUPutLEDEntry) led_handlers =

     QTAILQ_HEAD_INITIALIZER(led_handlers);

-int index_from_key(const char *key)

+int index_from_key(const char *key, size_t key_length)

 {

     int i;

     for (i = 0; QKeyCode_lookup[i] != NULL; i++) {

-        if (!strcmp(key, QKeyCode_lookup[i])) {

+        if (!strncmp(key, QKeyCode_lookup[i], key_length) &&

+            !QKeyCode_lookup[i][key_length]) {

             break;

         }

     }