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authorAndreas Jaeger <aj@suse.de>2000-05-18 05:35:38 +0000
committerAndreas Jaeger <aj@suse.de>2000-05-18 05:35:38 +0000
commit1261b97d10f60dfc7acc534a065bbe6ceef99f4f (patch)
treec25fe5bfa0e7dad407044c0519724702e874dca7
parentcc3f0ddb75ff6105a0fd869e6499c11e227bc787 (diff)
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Update.
	* sysdeps/generic/memmem.c (memmem): Check arguments to avoid
	possibly searching through the whole memory.
	Closes PR libc/1730, reported by Greg Hudson <ghudson@mit.edu>.
-rw-r--r--ChangeLog4
-rw-r--r--sysdeps/generic/memmem.c7
2 files changed, 10 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 086f8e4bdb..91e2c193fb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -21,6 +21,10 @@
 
 	* string/strings.h: Add pure and const attributes if possible.
 
+	* sysdeps/generic/memmem.c (memmem): Check arguments to avoid
+	possibly searching through the whole memory.
+	Closes PR libc/1730, reported by Greg Hudson <ghudson@mit.edu>.
+
 2000-05-17  Jakub Jelinek  <jakub@redhat.com>
 
 	* sysdeps/generic/dl-cache.h (_DL_CACHE_DEFAULT_ID): Only define if
diff --git a/sysdeps/generic/memmem.c b/sysdeps/generic/memmem.c
index 9e32f517b3..e9b270870a 100644
--- a/sysdeps/generic/memmem.c
+++ b/sysdeps/generic/memmem.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991, 92, 93, 94, 96, 97, 98 Free Software Foundation, Inc.
+/* Copyright (C) 1991,92,93,94,96,97,98,2000 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -38,6 +38,11 @@ memmem (haystack, haystack_len, needle, needle_len)
        the beginning of the string.  */
     return (void *) haystack;
 
+  /* Sanity check, otherwise the loop might search through the whole
+     memory.  */
+  if (__builtin_expect (haystack_len < needle_len, 0))
+    return NULL;
+
   for (begin = (const char *) haystack; begin <= last_possible; ++begin)
     if (begin[0] == ((const char *) needle)[0] &&
 	!memcmp ((const void *) &begin[1],