* [Qemu-devel] [PULL 1/1] hmp: fix sendkey out of bounds write (CVE-2015-8619)
2016-02-03 9:51 [Qemu-devel] [PULL 0/1] Monitor patches for 2016-02-03 Markus Armbruster
@ 2016-02-03 9:51 ` Markus Armbruster
2016-02-03 12:23 ` [Qemu-devel] [PULL 0/1] Monitor patches for 2016-02-03 Peter Maydell
1 sibling, 0 replies; 3+ messages in thread
From: Markus Armbruster @ 2016-02-03 9:51 UTC (permalink / raw)
To: qemu-devel; +Cc: Wolfgang Bumiller
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
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>
---
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 54f2620..9c571f5 100644
--- a/hmp.c
+++ b/hmp.c
@@ -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));
@@ -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;
}
@@ -1789,7 +1787,7 @@ 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 adac36d..116bc2b 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -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);
diff --git a/ui/input-legacy.c b/ui/input-legacy.c
index 35dfc27..3454055 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;
}
}
--
2.4.3
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