bb #6478: better return code for truncated ARJ

libclamav/scanners.c

@@ -378,6 +378,7 @@ static int cli_scanarj(cli_ctx *ctx, off_t sfx_offset, uint32_t *sfx_check)
         metadata.filename = NULL;
 	ret = cli_unarj_prepare_file(dir, &metadata);
 	if (ret != CL_SUCCESS) {
+	   cli_dbgmsg("ARJ: cli_unarj_prepare_file Error: %s\n", cl_strerror(ret));
 	   break;
 	}
 	file++;
@@ -391,6 +392,9 @@ static int cli_scanarj(cli_ctx *ctx, off_t sfx_offset, uint32_t *sfx_check)
 	    continue;
 	}
 	ret = cli_unarj_extract_file(dir, &metadata);
+	if (ret != CL_SUCCESS) {
+	   cli_dbgmsg("ARJ: cli_unarj_extract_file Error: %s\n", cl_strerror(ret));
+	}
 	if (metadata.ofd >= 0) {
 	    lseek(metadata.ofd, 0, SEEK_SET);
 	    rc = cli_magic_scandesc(metadata.ofd, ctx);

libclamav/unarj.c

@@ -761,7 +761,7 @@ static int decode_f(arj_metadata_t *metadata)
 	return CL_SUCCESS;
 }
 
-static uint32_t arj_unstore(arj_metadata_t *metadata, int ofd, uint32_t len)
+static int arj_unstore(arj_metadata_t *metadata, int ofd, uint32_t len)
 {
 	const unsigned char *data;
 	uint32_t rem;
@@ -774,15 +774,18 @@ static uint32_t arj_unstore(arj_metadata_t *metadata, int ofd, uint32_t len)
 	while (rem > 0) {
 		todo = (unsigned int) MIN(8192, rem);
 		data = fmap_need_off_once_len(metadata->map, metadata->offset, todo, &count);
-		if (!data || !count)
-		    return len - rem;
+		if (!data || !count) {
+			/* Truncated file, not enough bytes available */
+			return CL_EFORMAT;
+                }
 		metadata->offset += count;
 		if (cli_writen(ofd, data, count) != count) {
-			return len-rem-count;
+			/* File writing problem */
+			return CL_EWRITE;
 		}
 		rem -= count;
 	}
-	return len;
+	return CL_SUCCESS;
 }
 
 static int is_arj_archive(arj_metadata_t *metadata)
@@ -1028,11 +1031,6 @@ int cli_unarj_extract_file(const char *dirname, arj_metadata_t *metadata)
 	switch (metadata->method) {
 		case 0:
 			ret = arj_unstore(metadata, metadata->ofd, metadata->comp_size);
-			if (ret != metadata->comp_size) {
-				ret = CL_EWRITE;
-			} else {
-				ret = CL_SUCCESS;
-			}
 			break;
 		case 1:
 		case 2: