diff mbox series

[PULL,05/25] vnc: avoid underflow when accessing user-provided address

Message ID 20230421093316.17941-6-pbonzini@redhat.com
State New
Headers show
Series [PULL,01/25] mtest2make.py: teach suite name that are just "PROJECT" | expand

Commit Message

Paolo Bonzini April 21, 2023, 9:32 a.m. UTC 
If hostlen is zero, there is a possibility that addrstr[hostlen - 1]
underflows and, if a closing bracked is there, hostlen - 2 is passed
to g_strndup() on the next line.  If websocket==false then
addrstr[0] would be a colon, but if websocket==true this could in
principle happen.

Fix it by checking hostlen.

Reported by Coverity.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 ui/vnc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/ui/vnc.c b/ui/vnc.c
index bbd8b6baaeca..9d8a24dd8a69 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3751,7 +3751,7 @@  static int vnc_display_get_address(const char *addrstr,
 
         addr->type = SOCKET_ADDRESS_TYPE_INET;
         inet = &addr->u.inet;
-        if (addrstr[0] == '[' && addrstr[hostlen - 1] == ']') {
+        if (hostlen && addrstr[0] == '[' && addrstr[hostlen - 1] == ']') {
             inet->host = g_strndup(addrstr + 1, hostlen - 2);
         } else {
             inet->host = g_strndup(addrstr, hostlen);