From 36b47377c2d1a8d141d1ef810102748f27384f5c Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 25 May 2022 10:09:53 +0200
Subject: [PATCH 1/3] fopen: add Curl_fopen() for better overwriting of files
Bug: https://curl.se/docs/CVE-2022-32207.html
CVE-2022-32207
Reported-by: Harry Sintonen
Closes #9050
Upstream-commit: 20f9dd6bae50b7223171b17ba7798946e74f877f
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
CMakeLists.txt | 1 +
configure.ac | 1 +
lib/Makefile.inc | 2 +
lib/cookie.c | 17 ++----
lib/curl_config.h.cmake | 3 ++
lib/fopen.c | 113 ++++++++++++++++++++++++++++++++++++++++
lib/fopen.h | 30 +++++++++++
7 files changed, 154 insertions(+), 13 deletions(-)
create mode 100644 lib/fopen.c
create mode 100644 lib/fopen.h
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b77de6d..a0bfaad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -982,6 +982,7 @@ elseif(HAVE_LIBSOCKET)
set(CMAKE_REQUIRED_LIBRARIES socket)
endif()
+check_symbol_exists(fchmod "${CURL_INCLUDES}" HAVE_FCHMOD)
check_symbol_exists(basename "${CURL_INCLUDES}" HAVE_BASENAME)
check_symbol_exists(socket "${CURL_INCLUDES}" HAVE_SOCKET)
check_symbol_exists(select "${CURL_INCLUDES}" HAVE_SELECT)
diff --git a/configure.ac b/configure.ac
index d431870..7433bb9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4516,6 +4516,7 @@ AC_CHECK_DECLS([getpwuid_r], [], [AC_DEFINE(HAVE_DECL_GETPWUID_R_MISSING, 1, "Se
AC_CHECK_FUNCS([fnmatch \
+ fchmod \
geteuid \
getpass_r \
getppid \
diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index e8f110f..5139b03 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -130,6 +130,7 @@ LIB_CFILES = \
escape.c \
file.c \
fileinfo.c \
+ fopen.c \
formdata.c \
ftp.c \
ftplistparser.c \
@@ -261,6 +262,7 @@ LIB_HFILES = \
escape.h \
file.h \
fileinfo.h \
+ fopen.h \
formdata.h \
ftp.h \
ftplistparser.h \
diff --git a/lib/cookie.c b/lib/cookie.c
index 8a6aa1a..cb0c03b 100644
--- a/lib/cookie.c
+++ b/lib/cookie.c
@@ -97,8 +97,8 @@ Example set of cookies:
#include "curl_memrchr.h"
#include "inet_pton.h"
#include "parsedate.h"
-#include "rand.h"
#include "rename.h"
+#include "fopen.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
@@ -1537,17 +1537,8 @@ static int cookie_output(struct Curl_easy *data,
use_stdout = TRUE;
}
else {
- unsigned char randsuffix[9];
-
- if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
- return 2;
-
- tempstore = aprintf("%s.%s.tmp", filename, randsuffix);
- if(!tempstore)
- return 1;
-
- out = fopen(tempstore, FOPEN_WRITETEXT);
- if(!out)
+ error = Curl_fopen(data, filename, &out, &tempstore);
+ if(error)
goto error;
}
@@ -1594,7 +1585,7 @@ static int cookie_output(struct Curl_easy *data,
if(!use_stdout) {
fclose(out);
out = NULL;
- if(Curl_rename(tempstore, filename)) {
+ if(tempstore && Curl_rename(tempstore, filename)) {
unlink(tempstore);
goto error;
}
diff --git a/lib/curl_config.h.cmake b/lib/curl_config.h.cmake
index d2a0f43..c254359 100644
--- a/lib/curl_config.h.cmake
+++ b/lib/curl_config.h.cmake
@@ -148,6 +148,9 @@
/* Define to 1 if you have the <assert.h> header file. */
#cmakedefine HAVE_ASSERT_H 1
+/* Define to 1 if you have the `fchmod' function. */
+#cmakedefine HAVE_FCHMOD 1
+
/* Define to 1 if you have the `basename' function. */
#cmakedefine HAVE_BASENAME 1
diff --git a/lib/fopen.c b/lib/fopen.c
new file mode 100644
index 0000000..ad3691b
--- /dev/null
+++ b/lib/fopen.c
@@ -0,0 +1,113 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * SPDX-License-Identifier: curl
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if !defined(CURL_DISABLE_COOKIES) || !defined(CURL_DISABLE_ALTSVC) || \
+ defined(USE_HSTS)
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#include "urldata.h"
+#include "rand.h"
+#include "fopen.h"
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * Curl_fopen() opens a file for writing with a temp name, to be renamed
+ * to the final name when completed. If there is an existing file using this
+ * name at the time of the open, this function will clone the mode from that
+ * file. if 'tempname' is non-NULL, it needs a rename after the file is
+ * written.
+ */
+CURLcode Curl_fopen(struct Curl_easy *data, const char *filename,
+ FILE **fh, char **tempname)
+{
+ CURLcode result = CURLE_WRITE_ERROR;
+ unsigned char randsuffix[9];
+ char *tempstore = NULL;
+ struct_stat sb;
+ int fd = -1;
+ *tempname = NULL;
+
+ if(stat(filename, &sb) == -1 || !S_ISREG(sb.st_mode)) {
+ /* a non-regular file, fallback to direct fopen() */
+ *fh = fopen(filename, FOPEN_WRITETEXT);
+ if(*fh)
+ return CURLE_OK;
+ goto fail;
+ }
+
+ result = Curl_rand_hex(data, randsuffix, sizeof(randsuffix));
+ if(result)
+ goto fail;
+
+ tempstore = aprintf("%s.%s.tmp", filename, randsuffix);
+ if(!tempstore) {
+ result = CURLE_OUT_OF_MEMORY;
+ goto fail;
+ }
+
+ result = CURLE_WRITE_ERROR;
+ fd = open(tempstore, O_WRONLY | O_CREAT | O_EXCL, 0600);
+ if(fd == -1)
+ goto fail;
+
+#ifdef HAVE_FCHMOD
+ {
+ struct_stat nsb;
+ if((fstat(fd, &nsb) != -1) &&
+ (nsb.st_uid == sb.st_uid) && (nsb.st_gid == sb.st_gid)) {
+ /* if the user and group are the same, clone the original mode */
+ if(fchmod(fd, sb.st_mode) == -1)
+ goto fail;
+ }
+ }
+#endif
+
+ *fh = fdopen(fd, FOPEN_WRITETEXT);
+ if(!*fh)
+ goto fail;
+
+ *tempname = tempstore;
+ return CURLE_OK;
+
+fail:
+ if(fd != -1) {
+ close(fd);
+ unlink(tempstore);
+ }
+
+ free(tempstore);
+
+ *tempname = NULL;
+ return result;
+}
+
+#endif /* ! disabled */
diff --git a/lib/fopen.h b/lib/fopen.h
new file mode 100644
index 0000000..289e55f
--- /dev/null
+++ b/lib/fopen.h
@@ -0,0 +1,30 @@
+#ifndef HEADER_CURL_FOPEN_H
+#define HEADER_CURL_FOPEN_H
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * SPDX-License-Identifier: curl
+ *
+ ***************************************************************************/
+
+CURLcode Curl_fopen(struct Curl_easy *data, const char *filename,
+ FILE **fh, char **tempname);
+
+#endif
--
2.35.3
From bd7af48238b058e9b46fdf2e1333b355920c341c Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 25 May 2022 10:09:53 +0200
Subject: [PATCH 2/3] altsvc: use Curl_fopen()
Upstream-commit: fab970a5d19c1faa2052239ec1e2602b892cbeb2
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/altsvc.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/lib/altsvc.c b/lib/altsvc.c
index 242733b..4dc4078 100644
--- a/lib/altsvc.c
+++ b/lib/altsvc.c
@@ -34,7 +34,7 @@
#include "parsedate.h"
#include "sendf.h"
#include "warnless.h"
-#include "rand.h"
+#include "fopen.h"
#include "rename.h"
/* The last 3 #include files should be in this order */
@@ -329,8 +329,7 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
struct Curl_llist_element *n;
CURLcode result = CURLE_OK;
FILE *out;
- char *tempstore;
- unsigned char randsuffix[9];
+ char *tempstore = NULL;
if(!altsvc)
/* no cache activated */
@@ -344,17 +343,8 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
/* marked as read-only, no file or zero length file name */
return CURLE_OK;
- if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
- return CURLE_FAILED_INIT;
-
- tempstore = aprintf("%s.%s.tmp", file, randsuffix);
- if(!tempstore)
- return CURLE_OUT_OF_MEMORY;
-
- out = fopen(tempstore, FOPEN_WRITETEXT);
- if(!out)
- result = CURLE_WRITE_ERROR;
- else {
+ result = Curl_fopen(data, file, &out, &tempstore);
+ if(!result) {
fputs("# Your alt-svc cache. https://curl.se/docs/alt-svc.html\n"
"# This file was generated by libcurl! Edit at your own risk.\n",
out);
@@ -366,10 +356,10 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
break;
}
fclose(out);
- if(!result && Curl_rename(tempstore, file))
+ if(!result && tempstore && Curl_rename(tempstore, file))
result = CURLE_WRITE_ERROR;
- if(result)
+ if(result && tempstore)
unlink(tempstore);
}
free(tempstore);
--
2.35.3
From 2011622a36fa715f38277422241e77e25dfdf0d0 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 25 May 2022 10:09:54 +0200
Subject: [PATCH 3/3] hsts: use Curl_fopen()
Upstream-commit: d64115d7bb8ae4c136b620912da523c063f1d2ee
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/hsts.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/lib/hsts.c b/lib/hsts.c
index b9fa6f7..9d54c82 100644
--- a/lib/hsts.c
+++ b/lib/hsts.c
@@ -35,7 +35,7 @@
#include "sendf.h"
#include "strtoofft.h"
#include "parsedate.h"
-#include "rand.h"
+#include "fopen.h"
#include "rename.h"
/* The last 3 #include files should be in this order */
@@ -316,8 +316,7 @@ CURLcode Curl_hsts_save(struct Curl_easy *data, struct hsts *h,
struct Curl_llist_element *n;
CURLcode result = CURLE_OK;
FILE *out;
- char *tempstore;
- unsigned char randsuffix[9];
+ char *tempstore = NULL;
if(!h)
/* no cache activated */
@@ -331,17 +330,8 @@ CURLcode Curl_hsts_save(struct Curl_easy *data, struct hsts *h,
/* marked as read-only, no file or zero length file name */
goto skipsave;
- if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
- return CURLE_FAILED_INIT;
-
- tempstore = aprintf("%s.%s.tmp", file, randsuffix);
- if(!tempstore)
- return CURLE_OUT_OF_MEMORY;
-
- out = fopen(tempstore, FOPEN_WRITETEXT);
- if(!out)
- result = CURLE_WRITE_ERROR;
- else {
+ result = Curl_fopen(data, file, &out, &tempstore);
+ if(!result) {
fputs("# Your HSTS cache. https://curl.se/docs/hsts.html\n"
"# This file was generated by libcurl! Edit at your own risk.\n",
out);
@@ -353,10 +343,10 @@ CURLcode Curl_hsts_save(struct Curl_easy *data, struct hsts *h,
break;
}
fclose(out);
- if(!result && Curl_rename(tempstore, file))
+ if(!result && tempstore && Curl_rename(tempstore, file))
result = CURLE_WRITE_ERROR;
- if(result)
+ if(result && tempstore)
unlink(tempstore);
}
free(tempstore);
--
2.35.3