From: Wayne Davison <wayne@opencoder.net>
Date: Mon, 13 Jul 2020 04:51:51 +0000 (-0700)
Subject: Check for overflow the right way.
X-Git-Tag: v3.2.3pre1~93
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=91fff802b9513cf0ed616d3aea170d561f899fae;p=thirdparty%2Frsync.git

Check for overflow the right way.
---

diff --git a/options.c b/options.c
index 9ed16405..0ecabe8d 100644
--- a/options.c
+++ b/options.c
@@ -119,7 +119,6 @@ size_t bwlimit_writemax = 0;
 int ignore_existing = 0;
 int ignore_non_existing = 0;
 int need_messages_from_generator = 0;
-time_t stop_at_utime = 0;
 int max_delete = INT_MIN;
 OFF_T max_size = -1;
 OFF_T min_size = -1;
@@ -130,6 +129,7 @@ int checksum_seed = 0;
 int inplace = 0;
 int delay_updates = 0;
 int32 block_size = 0;
+time_t stop_at_utime = 0;
 char *skip_compress = NULL;
 char *copy_as = NULL;
 item_list dparam_list = EMPTY_ITEM_LIST;
@@ -2051,7 +2051,7 @@ int parse_arguments(int *argc_p, const char ***argv_p)
 			long val;
 			arg = poptGetOptArg(pc);
 			stop_at_utime = time(NULL);
-			if ((val = atol(arg) * 60) <= 0 || val + (long)stop_at_utime < 0) {
+			if ((val = atol(arg) * 60) <= 0 || LONG_MAX - val < stop_at_utime || (long)(time_t)val != val) {
 				snprintf(err_buf, sizeof err_buf, "invalid --stop-after value: %s\n", arg);
 				return 0;
 			}
diff --git a/rsync.h b/rsync.h
index be4d8550..9942a705 100644
--- a/rsync.h
+++ b/rsync.h
@@ -711,6 +711,10 @@ struct ht_int64_node {
 #define NAME_MAX 255
 #endif
 
+#ifndef SIZE_MAX
+#define SIZE_MAX ((size_t)-1)
+#endif
+
 #ifndef INADDR_NONE
 #define INADDR_NONE 0xffffffff
 #endif
diff --git a/util.c b/util.c
index 3a50e44f..f5588324 100644
--- a/util.c
+++ b/util.c
@@ -1632,28 +1632,27 @@ void *expand_item_list(item_list *lp, size_t item_size, const char *desc, int in
 	/* First time through, 0 <= 0, so list is expanded. */
 	if (lp->malloced <= lp->count) {
 		void *new_ptr;
-		size_t new_size = lp->malloced;
+		size_t expand_size;
 		if (incr < 0)
-			new_size += -incr; /* increase slowly */
-		else if (new_size < (size_t)incr)
-			new_size = incr;
-		else if (new_size)
-			new_size *= 2;
+			expand_size = -incr; /* increase slowly */
+		else if (lp->malloced < (size_t)incr)
+			expand_size = incr - lp->malloced;
+		else if (lp->malloced)
+			expand_size = lp->malloced; /* double in size */
 		else
-			new_size = 1;
-		if (new_size <= lp->malloced)
+			expand_size = 1;
+		if (SIZE_MAX/item_size - expand_size < lp->malloced)
 			overflow_exit("expand_item_list");
-		new_ptr = realloc_buf(lp->items, new_size * item_size);
+		expand_size += lp->malloced;
+		new_ptr = realloc_buf(lp->items, expand_size * item_size);
 		if (DEBUG_GTE(FLIST, 3)) {
 			rprintf(FINFO, "[%s] expand %s to %s bytes, did%s move\n",
-				who_am_i(), desc, big_num(new_size * item_size),
+				who_am_i(), desc, big_num(expand_size * item_size),
 				new_ptr == lp->items ? " not" : "");
 		}
-		if (!new_ptr)
-			out_of_memory("expand_item_list");
 
 		lp->items = new_ptr;
-		lp->malloced = new_size;
+		lp->malloced = expand_size;
 	}
 	return (char*)lp->items + (lp->count++ * item_size);
 }
diff --git a/xattrs.c b/xattrs.c
index b10c2567..bcb4bcac 100644
--- a/xattrs.c
+++ b/xattrs.c
@@ -199,7 +199,7 @@ static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr
 
 	if (!datum_len && !extra_len)
 		extra_len = 1; /* request non-zero amount of memory */
-	if (datum_len + extra_len < datum_len)
+	if (SIZE_MAX - datum_len < extra_len)
 		overflow_exit("get_xattr_data");
 	ptr = new_array(char, datum_len + extra_len);
 
@@ -748,7 +748,7 @@ int recv_xattr_request(struct file_struct *file, int f_in)
 		old_datum = rxa->datum;
 		rxa->datum_len = read_varint(f_in);
 
-		if (rxa->name_len + rxa->datum_len < rxa->name_len)
+		if (SIZE_MAX - rxa->name_len < rxa->datum_len)
 			overflow_exit("recv_xattr_request");
 		rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
 		name = rxa->datum + rxa->datum_len;
@@ -799,8 +799,7 @@ void receive_xattr(int f, struct file_struct *file)
 		size_t datum_len = read_varint(f);
 		size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + MAX_DIGEST_LEN : datum_len;
 		size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
-		if ((dget_len + extra_len < dget_len)
-		 || (dget_len + extra_len + name_len < dget_len + extra_len))
+		if (SIZE_MAX - dget_len < extra_len || SIZE_MAX - dget_len - extra_len < name_len)
 			overflow_exit("receive_xattr");
 		ptr = new_array(char, dget_len + extra_len + name_len);
 		name = ptr + dget_len + extra_len;