bb#1968

ChangeLog

@@ -1,3 +1,7 @@
+Tue May  4 18:47:31 CEST 2010 (acab)
+------------------------------------
+ * libclamav: no ERROR on void mapping (bb#1968)
+
 Tue May  4 16:47:57 CEST 2010 (tk)
 ----------------------------------
  * libclamav/matcher-ac.c: fix counting of subsig matches (bb#2001)

libclamav/fmap.c

@@ -92,12 +92,18 @@ pthread_mutex_t fmap_mutex = PTHREAD_MUTEX_INITIALIZER;
 ssize_t pread(int fd, void *buf, size_t count, off_t offset);
 
 fmap_t *fmap(int fd, off_t offset, size_t len) {
+    int unused;
+    return fmap_check_empty(fd, offset, len, &unused);
+}
+
+fmap_t *fmap_check_empty(int fd, off_t offset, size_t len, int *empty) {
     unsigned int pages, mapsz, hdrsz;
     unsigned short dumb = 1;
     int pgsz = cli_getpagesize();
     struct stat st;
     fmap_t *m;
 
+    *empty = 0;
     if(fstat(fd, &st)) {
 	cli_warnmsg("fmap: fstat failed\n");
 	return NULL;
@@ -108,7 +114,8 @@ fmap_t *fmap(int fd, off_t offset, size_t len) {
     }
     if(!len) len = st.st_size - offset; /* bound checked later */
     if(!len) {
-	cli_warnmsg("fmap: attempted void mapping\n");
+	cli_dbgmsg("fmap: attempted void mapping\n");
+	*empty = 1;
 	return NULL;
     }
     if(!CLI_ISCONTAINED(0, st.st_size, offset, len)) {

libclamav/fmap.h

@@ -48,6 +48,7 @@ typedef struct {
 } fmap_t;
 
 fmap_t *fmap(int fd, off_t offset, size_t len);
+fmap_t *fmap_check_empty(int fd, off_t offset, size_t len, int *empty);
 void funmap(fmap_t *m);
 void *fmap_need_off(fmap_t *m, size_t at, size_t len);
 void *fmap_need_off_once(fmap_t *m, size_t at, size_t len);

libclamav/matcher.c

@@ -402,15 +402,17 @@ static int matchicon(cli_ctx *ctx, const char *grp1, const char *grp2)
 
 int cli_scandesc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struct cli_matched_type **ftoffset, unsigned int acmode)
 {
-    int ret = CL_EMEM;
+    int ret = CL_EMEM, empty;
     fmap_t *map = *ctx->fmap;
 
-    if((*ctx->fmap = fmap(desc, 0, 0))) {
+    if((*ctx->fmap = fmap_check_empty(desc, 0, 0, &empty))) {
 	ret = cli_fmap_scandesc(ctx, ftype, ftonly, ftoffset, acmode, NULL);
 	map->dont_cache_flag = (*ctx->fmap)->dont_cache_flag;
 	funmap(*ctx->fmap);
     }
     *ctx->fmap = map;
+    if(empty)
+	return CL_CLEAN;
     return ret;
 }