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From 697cb1880b624f83bc9e926c3614d070eb365f06 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Mon, 2 Dec 2019 12:31:47 +0100
Subject: [PATCH 3/9] CryptoPkg/Crt: turn strchr() into a function
 (CVE-2019-14553)
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RH-Author: Laszlo Ersek <lersek@redhat.com>
Message-id: <20191117220052.15700-4-lersek@redhat.com>
Patchwork-id: 92458
O-Subject: [RHEL-8.2.0 edk2 PATCH 3/9] CryptoPkg/Crt: turn strchr() into a function (CVE-2019-14553)
Bugzilla: 1536624
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>

According to the ISO C standard, strchr() is a function. We #define it as
a macro. Unfortunately, our macro evaluates the first argument ("str")
twice. If the expression passed for "str" has side effects, the behavior
may be undefined.

In a later patch in this series, we're going to resurrect "inet_pton.c"
(originally from the StdLib package), which calls strchr() just like that:

  strchr((xdigits = xdigits_l), ch)
  strchr((xdigits = xdigits_u), ch)

To enable this kind of function call, turn strchr() into a function.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Sivaraman Nainar <sivaramann@amiindia.co.in>
Cc: Xiaoyu Lu <xiaoyux.lu@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=960
CVE: CVE-2019-14553
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
(cherry picked from commit eb520d94dba7369d1886cd5522d5a2c36fb02209)
---
 CryptoPkg/Library/BaseCryptLib/SysCall/CrtWrapper.c | 5 +++++
 CryptoPkg/Library/Include/CrtLibSupport.h           | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CryptoPkg/Library/BaseCryptLib/SysCall/CrtWrapper.c b/CryptoPkg/Library/BaseCryptLib/SysCall/CrtWrapper.c
index 71a2ef3..42235ab 100644
--- a/CryptoPkg/Library/BaseCryptLib/SysCall/CrtWrapper.c
+++ b/CryptoPkg/Library/BaseCryptLib/SysCall/CrtWrapper.c
@@ -115,6 +115,11 @@ QuickSortWorker (
 // -- String Manipulation Routines --
 //
 
+char *strchr(const char *str, int ch)
+{
+  return ScanMem8 (str, AsciiStrSize (str), (UINT8)ch);
+}
+
 /* Scan a string for the last occurrence of a character */
 char *strrchr (const char *str, int c)
 {
diff --git a/CryptoPkg/Library/Include/CrtLibSupport.h b/CryptoPkg/Library/Include/CrtLibSupport.h
index 5806f50..b90da20 100644
--- a/CryptoPkg/Library/Include/CrtLibSupport.h
+++ b/CryptoPkg/Library/Include/CrtLibSupport.h
@@ -147,6 +147,7 @@ int            isupper     (int);
 int            tolower     (int);
 int            strcmp      (const char *, const char *);
 int            strncasecmp (const char *, const char *, size_t);
+char           *strchr     (const char *, int);
 char           *strrchr    (const char *, int);
 unsigned long  strtoul     (const char *, char **, int);
 long           strtol      (const char *, char **, int);
@@ -188,7 +189,6 @@ void           abort       (void);
 #define strcpy(strDest,strSource)         AsciiStrCpyS(strDest,MAX_STRING_SIZE,strSource)
 #define strncpy(strDest,strSource,count)  AsciiStrnCpyS(strDest,MAX_STRING_SIZE,strSource,(UINTN)count)
 #define strcat(strDest,strSource)         AsciiStrCatS(strDest,MAX_STRING_SIZE,strSource)
-#define strchr(str,ch)                    ScanMem8((VOID *)(str),AsciiStrSize(str),(UINT8)ch)
 #define strncmp(string1,string2,count)    (int)(AsciiStrnCmp(string1,string2,(UINTN)(count)))
 #define strcasecmp(str1,str2)             (int)AsciiStriCmp(str1,str2)
 #define sprintf(buf,...)                  AsciiSPrint(buf,MAX_STRING_SIZE,__VA_ARGS__)
-- 
1.8.3.1