Module Name: src
Committed By: riastradh
Date: Mon Jun 27 04:06:48 UTC 2022
Modified Files:
src/sys/kern: uipc_syscalls.c
Log Message:
sendmsg(2): Avoid buffer overrun in ktrace of invalid cmsghdr.
Reported-by: syzbot+efded148140b23425...@syzkaller.appspotmail.com
To generate a diff of this commit:
cvs rdiff -u -r1.202 -r1.203 src/sys/kern/uipc_syscalls.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/uipc_syscalls.c
diff -u src/sys/kern/uipc_syscalls.c:1.202 src/sys/kern/uipc_syscalls.c:1.203
--- src/sys/kern/uipc_syscalls.c:1.202 Sat Oct 2 17:37:21 2021
+++ src/sys/kern/uipc_syscalls.c Mon Jun 27 04:06:48 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: uipc_syscalls.c,v 1.202 2021/10/02 17:37:21 thorpej Exp $ */
+/* $NetBSD: uipc_syscalls.c,v 1.203 2022/06/27 04:06:48 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -61,7 +61,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_syscalls.c,v 1.202 2021/10/02 17:37:21 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_syscalls.c,v 1.203 2022/06/27 04:06:48 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_pipe.h"
@@ -1627,6 +1627,10 @@ sockargs(struct mbuf **mp, const void *b
mhdr.msg_controllen = buflen;
for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&mhdr); cmsg;
cmsg = CMSG_NXTHDR(&mhdr, cmsg)) {
+ KASSERT(((char *)cmsg - mtod(m, char *)) <= buflen);
+ if (cmsg->cmsg_len >
+ buflen - ((char *)cmsg - mtod(m, char *)))
+ break;
ktrkuser(mbuftypes[type], cmsg, cmsg->cmsg_len);
}
return 0;
