From 13ca8fee0c897121ae79ae644a212418398dfea7 Mon Sep 17 00:00:00 2001
From: Amin Hassani <ahassani@chromium.org>
Date: Fri, 8 Mar 2019 09:58:20 -0800
Subject: [PATCH] Check for upper bounds of nselectors.

Currently there is no check for the upper bounds of the
nselectors. Hence, a corrupt input can cause a segfault.

This issue was discovered by one of our fuzzers. The actual error was:

../bzip2-1.0.6/decompress.c:299:10: runtime error: index 18002 out of bounds for type 'UChar [18002]'
---
 decompress.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/decompress.c b/decompress.c
index 311f566..391552d 100644
--- a/decompress.c
+++ b/decompress.c
@@ -288,6 +288,7 @@ Int32 BZ2_decompress ( DState* s )
       if (nGroups < 2 || nGroups > 6) RETURN(BZ_DATA_ERROR);
       GET_BITS(BZ_X_SELECTOR_2, nSelectors, 15);
       if (nSelectors < 1) RETURN(BZ_DATA_ERROR);
+      if (nSelectors > BZ_MAX_SELECTORS) RETURN(BZ_DATA_ERROR);
       for (i = 0; i < nSelectors; i++) {
          j = 0;
          while (True) {
-- 
2.21.0.360.g471c308f928-goog