linux-kernel - Re: Crash in VirtualBox virtual machines running kernel 6.5

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <202307190835.752D710D@keescook>
Date:   Wed, 19 Jul 2023 08:36:53 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Larry Finger <Larry.Finger@...inger.net>
Cc:     Hans de Goede <hdegoede@...hat.com>,
        Azeem Shaikh <azeemshaikh38@...il.com>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-hardening@...r.kernel.org,
        "Gustavo A. R. Silva" <gustavoars@...nel.org>
Subject: Re: Crash in VirtualBox virtual machines running kernel 6.5

Okay, please try:

diff --git a/fs/vboxsf/shfl_hostintf.h b/fs/vboxsf/shfl_hostintf.h
index aca829062c12..902fe3224453 100644
--- a/fs/vboxsf/shfl_hostintf.h
+++ b/fs/vboxsf/shfl_hostintf.h
@@ -68,12 +68,11 @@ struct shfl_string {
 
 	/** UTF-8 or UTF-16 string. Nul terminated. */
 	union {
-		u8 utf8[2];
-		u16 utf16[1];
-		u16 ucs2[1]; /* misnomer, use utf16. */
+		DECLARE_FLEX_ARRAY(u8, utf8);
+		DECLARE_FLEX_ARRAY(u16, utf16);
 	} string;
 };
-VMMDEV_ASSERT_SIZE(shfl_string, 6);
+VMMDEV_ASSERT_SIZE(shfl_string, 4);
 
 /* The size of shfl_string w/o the string part. */
 #define SHFLSTRING_HEADER_SIZE  4


The size assert doesn't seem to be used anywhere else, but I can do a
more careful binary analysis later today...

-- 
Kees Cook