Module Name:    src
Committed By:   martin
Date:           Tue Aug  8 16:12:57 UTC 2017

Modified Files:
        src/sys/dev [netbsd-8]: vnd.c

Log Message:
Pull up following revision(s) (requested by spz in ticket #190):
        sys/dev/vnd.c: revision 1.260
        sys/dev/vnd.c: revision 1.262
Put in a litany of judicious bounds checks around vnd headers.
Thought I was done with this crap after I rewrote vndcompress(1)!
>From Ilja Van Sprundel.
Appease toxic bullshit warning from gcc.
If you have a better way to write a useful bounds check that happens
to always pass on LP64 but doesn't always on LP32, without making it
fail to compile on LP64 or making it an #ifdef conditional on LP32,
please put it in here instead.


To generate a diff of this commit:
cvs rdiff -u -r1.259 -r1.259.6.1 src/sys/dev/vnd.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/dev/vnd.c
diff -u src/sys/dev/vnd.c:1.259 src/sys/dev/vnd.c:1.259.6.1
--- src/sys/dev/vnd.c:1.259	Sat Mar 25 07:00:33 2017
+++ src/sys/dev/vnd.c	Tue Aug  8 16:12:56 2017
@@ -1,4 +1,4 @@
-/*	$NetBSD: vnd.c,v 1.259 2017/03/25 07:00:33 pgoyette Exp $	*/
+/*	$NetBSD: vnd.c,v 1.259.6.1 2017/08/08 16:12:56 martin Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2008 The NetBSD Foundation, Inc.
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.259 2017/03/25 07:00:33 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.259.6.1 2017/08/08 16:12:56 martin Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_vnd.h"
@@ -1284,6 +1284,13 @@ vndioctl(dev_t dev, u_long cmd, void *da
 				goto close_and_exit;
 			}
 
+			if (ntohl(ch->block_size) == 0 ||
+			    ntohl(ch->num_blocks) > UINT32_MAX - 1) {
+				free(ch, M_TEMP);
+				VOP_UNLOCK(nd.ni_vp);
+				goto close_and_exit;
+			}
+
 			/* save some header info */
 			vnd->sc_comp_blksz = ntohl(ch->block_size);
 			/* note last offset is the file byte size */
@@ -1294,20 +1301,40 @@ vndioctl(dev_t dev, u_long cmd, void *da
 				error = EINVAL;
 				goto close_and_exit;
 			}
-			if (sizeof(struct vnd_comp_header) +
-			  sizeof(u_int64_t) * vnd->sc_comp_numoffs >
-			  vattr.va_size) {
+			KASSERT(0 < vnd->sc_comp_blksz);
+			KASSERT(0 < vnd->sc_comp_numoffs);
+			/*
+			 * @#^@!$& gcc -Wtype-limits refuses to let me
+			 * write SIZE_MAX/sizeof(uint64_t) < numoffs,
+			 * because the range of the type on amd64 makes
+			 * the comparisons always false.
+			 */
+#if SIZE_MAX <= UINT32_MAX*(64/CHAR_BIT)
+			if (SIZE_MAX/sizeof(uint64_t) < vnd->sc_comp_numoffs) {
+				VOP_UNLOCK(nd.ni_vp);
+				error = EINVAL;
+				goto close_and_exit;
+			}
+#endif
+			if ((vattr.va_size < sizeof(struct vnd_comp_header)) ||
+			    (vattr.va_size - sizeof(struct vnd_comp_header) <
+				sizeof(uint64_t)*vnd->sc_comp_numoffs) ||
+			    (UQUAD_MAX/vnd->sc_comp_blksz <
+				vnd->sc_comp_numoffs - 1)) {
 				VOP_UNLOCK(nd.ni_vp);
 				error = EINVAL;
 				goto close_and_exit;
 			}
 
 			/* set decompressed file size */
+			KASSERT(vnd->sc_comp_numoffs - 1 <=
+			    UQUAD_MAX/vnd->sc_comp_blksz);
 			vattr.va_size =
 			    ((u_quad_t)vnd->sc_comp_numoffs - 1) *
 			     (u_quad_t)vnd->sc_comp_blksz;
 
 			/* allocate space for all the compressed offsets */
+			__CTASSERT(UINT32_MAX <= UQUAD_MAX/sizeof(uint64_t));
 			vnd->sc_comp_offsets =
 			malloc(sizeof(u_int64_t) * vnd->sc_comp_numoffs,
 			M_DEVBUF, M_WAITOK);

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