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[PATCH 1/3] [D] libiberty: Remove stack buffer in dlang_parse_real
- From: Iain Buclaw <ibuclaw at gdcproject dot org>
- To: gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 26 May 2017 17:48:27 +0200
- Subject: [PATCH 1/3] [D] libiberty: Remove stack buffer in dlang_parse_real
- Authentication-results: sourceware.org; auth=none
Hi,
This patch fixes a problem in the D demangler where an abnormally long
mangled floating point literal would cause the program write past the
allocated stack buffer. This should never happen with a valid D
symbol, but we should be able to handle anything thrown at us.
---
commit 62d51a8de1fa6543f11ff0d9f97b3ce714023089
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date: Fri May 26 15:29:50 2017 +0200
libiberty/ChangeLog:
2017-05-26 Iain Buclaw <ibuclaw@gdcproject.org>
* d-demangle.c (dlang_parse_real): Remove stack buffer, write
the demangled hexadecimal directly to string.
* testsuite/d-demangle-expected: Add tests.
diff --git a/libiberty/d-demangle.c b/libiberty/d-demangle.c
index ec5508e2777..030cab3333f 100644
--- a/libiberty/d-demangle.c
+++ b/libiberty/d-demangle.c
@@ -1025,9 +1025,6 @@ dlang_parse_integer (string *decl, const char *mangled, char type)
static const char *
dlang_parse_real (string *decl, const char *mangled)
{
- char buffer[64];
- int len = 0;
-
/* Handle NAN and +-INF. */
if (strncmp (mangled, "NAN", 3) == 0)
{
@@ -1051,23 +1048,22 @@ dlang_parse_real (string *decl, const char *mangled)
/* Hexadecimal prefix and leading bit. */
if (*mangled == 'N')
{
- buffer[len++] = '-';
+ string_append (decl, "-");
mangled++;
}
if (!ISXDIGIT (*mangled))
return NULL;
- buffer[len++] = '0';
- buffer[len++] = 'x';
- buffer[len++] = *mangled;
- buffer[len++] = '.';
+ string_append (decl, "0x");
+ string_appendn (decl, mangled, 1);
+ string_append (decl, ".");
mangled++;
/* Significand. */
while (ISXDIGIT (*mangled))
{
- buffer[len++] = *mangled;
+ string_appendn (decl, mangled, 1);
mangled++;
}
@@ -1075,26 +1071,21 @@ dlang_parse_real (string *decl, const char *mangled)
if (*mangled != 'P')
return NULL;
- buffer[len++] = 'p';
+ string_append (decl, "p");
mangled++;
if (*mangled == 'N')
{
- buffer[len++] = '-';
+ string_append (decl, "-");
mangled++;
}
while (ISDIGIT (*mangled))
{
- buffer[len++] = *mangled;
+ string_appendn (decl, mangled, 1);
mangled++;
}
- /* Write out the demangled hexadecimal, rather than trying to
- convert the buffer into a floating-point value. */
- buffer[len] = '\0';
- len = strlen (buffer);
- string_appendn (decl, buffer, len);
return mangled;
}
diff --git a/libiberty/testsuite/d-demangle-expected b/libiberty/testsuite/d-demangle-expected
index 626d7c2d980..950d4955d8f 100644
--- a/libiberty/testsuite/d-demangle-expected
+++ b/libiberty/testsuite/d-demangle-expected
@@ -838,6 +838,10 @@ _D8demangle52__T4testVrcN0C4CCCCCCCCCCCCCDP4c0B666666666666666P6Zv
demangle.test!(-0x0.C4CCCCCCCCCCCCCDp4+0x0.B666666666666666p6i)
#
--format=dlang
+_D8demangle91__T4testVde000111222333444555666777888999AAABBBCCCDDDEEEFFFP000111222333444555666777888999Zv
+demangle.test!(0x0.00111222333444555666777888999AAABBBCCCDDDEEEFFFp000111222333444555666777888999)
+#
+--format=dlang
_D8demangle22__T4testVG3ua3_616263Zv
demangle.test!("abc")
#