From fcbfb1c6ee2ccf3a69db34550e5fdbb48ae92b2a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?T=C3=B6r=C3=B6k=20Edvin?= <edwin@clamav.net>
Date: Thu, 9 Sep 2010 12:30:59 +0300
Subject: [PATCH] Properly skip bytecodes with long lines.

Prevent 'Line too long for provided buffer'.
We must skip using a buffer of length declared in cbc header, not 4096.
So perform the skip in bytecode.c rather than readdb.c (which doesn't know the
length). The skip in readdb.c is good for skipping the source code, so keep it.
---
 ChangeLog            |  4 ++++
 libclamav/bytecode.c | 33 ++++++++++++++++++++++++---------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a25b02599..c1e5d6077 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Sep  9 12:30:34 EEST 2010 (edwin)
+-------------------------------------
+ * libclamav/bytecode.c: properly skip bytecodes with long lines.
+
 Wed Sep  8 00:00:18 CEST 2010 (acab)
 ------------------------------------
  * unit_tests: add VI unit tests
diff --git a/libclamav/bytecode.c b/libclamav/bytecode.c
index 9f208273c..6c43ea84b 100644
--- a/libclamav/bytecode.c
+++ b/libclamav/bytecode.c
@@ -1392,7 +1392,8 @@ enum parse_state {
     PARSE_BC_LSIG,
     PARSE_MD_OPT_HEADER,
     PARSE_FUNC_HEADER,
-    PARSE_BB
+    PARSE_BB,
+    PARSE_SKIP
 };
 
 int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int trust)
@@ -1417,9 +1418,16 @@ int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int tru
     }
     cli_chomp(firstbuf);
     rc = parseHeader(bc, (unsigned char*)firstbuf, &linelength);
+    state = PARSE_BC_LSIG;
     if (rc == CL_BREAK) {
+	const char *len = strchr(firstbuf, ':');
 	bc->state = bc_skip;
-	return CL_SUCCESS;
+	if (!linelength) {
+	    linelength = len ? atoi(len+1) : 4096;
+	}
+	cli_dbgmsg("line: %d\n", linelength);
+	state = PARSE_SKIP;
+	rc = CL_SUCCESS;
     }
     if (rc != CL_SUCCESS) {
 	cli_errmsg("Error at bytecode line %u\n", row);
@@ -1430,7 +1438,6 @@ int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int tru
 	cli_errmsg("Out of memory allocating line of length %u\n", linelength);
 	return CL_EMEM;
     }
-    state = PARSE_BC_LSIG;
     while (cli_dbgets(buffer, linelength, f, dbio) && !end) {
 	cli_chomp(buffer);
 	row++;
@@ -1439,8 +1446,8 @@ int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int tru
 		rc = parseLSig(bc, buffer);
 		if (rc == CL_BREAK) /* skip */ {
 		    bc->state = bc_skip;
-		    free(buffer);
-		    return CL_SUCCESS;
+		    state = PARSE_SKIP;
+		    continue;
 		}
 		if (rc != CL_SUCCESS) {
 		    cli_errmsg("Error at bytecode line %u\n", row);
@@ -1462,8 +1469,8 @@ int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int tru
 		rc = parseApis(bc, (unsigned char*)buffer);
 		if (rc == CL_BREAK) /* skip */ {
 		    bc->state = bc_skip;
-		    free(buffer);
-		    return CL_SUCCESS;
+		    state = PARSE_SKIP;
+		    continue;
 		}
 		if (rc != CL_SUCCESS) {
 		    cli_errmsg("Error at bytecode line %u\n", row);
@@ -1476,8 +1483,8 @@ int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int tru
 		rc = parseGlobals(bc, (unsigned char*)buffer);
 		if (rc == CL_BREAK) /* skip */ {
 		    bc->state = bc_skip;
-		    free(buffer);
-		    return CL_SUCCESS;
+		    state = PARSE_SKIP;
+		    continue;
 		}
 		if (rc != CL_SUCCESS) {
 		    cli_errmsg("Error at bytecode line %u\n", row);
@@ -1531,6 +1538,14 @@ int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int tru
 		    current_func++;
 		}
 		break;
+	    case PARSE_SKIP:
+		/* stop at S (source code), readdb.c knows how to skip this one
+		 * */
+		if (buffer[0] == 'S')
+		    end = 1;
+		/* noop parse, but we need to use dbgets with dynamic buffer,
+		 * otherwise we get 'Line too long for provided buffer' */
+		break;
 	}
     }
     free(buffer);