Skip to content

Commit

Permalink
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
Blub authored and Markus Armbruster committed Feb 3, 2016
1 parent c65db77 commit 64ffbe0
Show file tree
Hide file tree
Showing 3 changed files with 12 additions and 13 deletions.
18 changes: 8 additions & 10 deletions hmp.c
Expand Up @@ -1731,21 +1731,18 @@ 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));
Expand All @@ -1758,16 +1755,17 @@ 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;
}
Expand All @@ -1789,7 +1787,7 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict)
return;

err_out:
monitor_printf(mon, "invalid parameter: %s\n", keyname_buf);
monitor_printf(mon, "invalid parameter: %.*s\n", keyname_len, keys);
goto out;
}

Expand Down
2 changes: 1 addition & 1 deletion include/ui/console.h
Expand Up @@ -448,7 +448,7 @@ 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);
Expand Down
5 changes: 3 additions & 2 deletions ui/input-legacy.c
Expand Up @@ -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;
}
}
Expand Down

0 comments on commit 64ffbe0

Please sign in to comment.