995bcc5329
In GNU patch through 2.7.6, the following of symlinks is mishandled in certain cases other than input files. This affects inp.c and util.c. https://nvd.nist.gov/vuln/detail/CVE-2019-13636 Signed-off-by: Russell Senior <russell@personaltelco.net>
109 lines
3.7 KiB
Diff
109 lines
3.7 KiB
Diff
From dce4683cbbe107a95f1f0d45fabc304acfb5d71a Mon Sep 17 00:00:00 2001
|
|
From: Andreas Gruenbacher <agruen@gnu.org>
|
|
Date: Mon, 15 Jul 2019 16:21:48 +0200
|
|
Subject: Don't follow symlinks unless --follow-symlinks is given
|
|
|
|
* src/inp.c (plan_a, plan_b), src/util.c (copy_to_fd, copy_file,
|
|
append_to_file): Unless the --follow-symlinks option is given, open files with
|
|
the O_NOFOLLOW flag to avoid following symlinks. So far, we were only doing
|
|
that consistently for input files.
|
|
* src/util.c (create_backup): When creating empty backup files, (re)create them
|
|
with O_CREAT | O_EXCL to avoid following symlinks in that case as well.
|
|
---
|
|
src/inp.c | 12 ++++++++++--
|
|
src/util.c | 14 +++++++++++---
|
|
2 files changed, 21 insertions(+), 5 deletions(-)
|
|
|
|
diff --git a/src/inp.c b/src/inp.c
|
|
index 32d0919..22d7473 100644
|
|
--- a/src/inp.c
|
|
+++ b/src/inp.c
|
|
@@ -238,8 +238,13 @@ plan_a (char const *filename)
|
|
{
|
|
if (S_ISREG (instat.st_mode))
|
|
{
|
|
- int ifd = safe_open (filename, O_RDONLY|binary_transput, 0);
|
|
+ int flags = O_RDONLY | binary_transput;
|
|
size_t buffered = 0, n;
|
|
+ int ifd;
|
|
+
|
|
+ if (! follow_symlinks)
|
|
+ flags |= O_NOFOLLOW;
|
|
+ ifd = safe_open (filename, flags, 0);
|
|
if (ifd < 0)
|
|
pfatal ("can't open file %s", quotearg (filename));
|
|
|
|
@@ -340,6 +345,7 @@ plan_a (char const *filename)
|
|
static void
|
|
plan_b (char const *filename)
|
|
{
|
|
+ int flags = O_RDONLY | binary_transput;
|
|
int ifd;
|
|
FILE *ifp;
|
|
int c;
|
|
@@ -353,7 +359,9 @@ plan_b (char const *filename)
|
|
|
|
if (instat.st_size == 0)
|
|
filename = NULL_DEVICE;
|
|
- if ((ifd = safe_open (filename, O_RDONLY | binary_transput, 0)) < 0
|
|
+ if (! follow_symlinks)
|
|
+ flags |= O_NOFOLLOW;
|
|
+ if ((ifd = safe_open (filename, flags, 0)) < 0
|
|
|| ! (ifp = fdopen (ifd, binary_transput ? "rb" : "r")))
|
|
pfatal ("Can't open file %s", quotearg (filename));
|
|
if (TMPINNAME_needs_removal)
|
|
diff --git a/src/util.c b/src/util.c
|
|
index 1cc08ba..fb38307 100644
|
|
--- a/src/util.c
|
|
+++ b/src/util.c
|
|
@@ -388,7 +388,7 @@ create_backup (char const *to, const struct stat *to_st, bool leave_original)
|
|
|
|
try_makedirs_errno = ENOENT;
|
|
safe_unlink (bakname);
|
|
- while ((fd = safe_open (bakname, O_CREAT | O_WRONLY | O_TRUNC, 0666)) < 0)
|
|
+ while ((fd = safe_open (bakname, O_CREAT | O_EXCL | O_WRONLY | O_TRUNC, 0666)) < 0)
|
|
{
|
|
if (errno != try_makedirs_errno)
|
|
pfatal ("Can't create file %s", quotearg (bakname));
|
|
@@ -579,10 +579,13 @@ create_file (char const *file, int open_flags, mode_t mode,
|
|
static void
|
|
copy_to_fd (const char *from, int tofd)
|
|
{
|
|
+ int from_flags = O_RDONLY | O_BINARY;
|
|
int fromfd;
|
|
ssize_t i;
|
|
|
|
- if ((fromfd = safe_open (from, O_RDONLY | O_BINARY, 0)) < 0)
|
|
+ if (! follow_symlinks)
|
|
+ from_flags |= O_NOFOLLOW;
|
|
+ if ((fromfd = safe_open (from, from_flags, 0)) < 0)
|
|
pfatal ("Can't reopen file %s", quotearg (from));
|
|
while ((i = read (fromfd, buf, bufsize)) != 0)
|
|
{
|
|
@@ -625,6 +628,8 @@ copy_file (char const *from, char const *to, struct stat *tost,
|
|
else
|
|
{
|
|
assert (S_ISREG (mode));
|
|
+ if (! follow_symlinks)
|
|
+ to_flags |= O_NOFOLLOW;
|
|
tofd = create_file (to, O_WRONLY | O_BINARY | to_flags, mode,
|
|
to_dir_known_to_exist);
|
|
copy_to_fd (from, tofd);
|
|
@@ -640,9 +645,12 @@ copy_file (char const *from, char const *to, struct stat *tost,
|
|
void
|
|
append_to_file (char const *from, char const *to)
|
|
{
|
|
+ int to_flags = O_WRONLY | O_APPEND | O_BINARY;
|
|
int tofd;
|
|
|
|
- if ((tofd = safe_open (to, O_WRONLY | O_BINARY | O_APPEND, 0)) < 0)
|
|
+ if (! follow_symlinks)
|
|
+ to_flags |= O_NOFOLLOW;
|
|
+ if ((tofd = safe_open (to, to_flags, 0)) < 0)
|
|
pfatal ("Can't reopen file %s", quotearg (to));
|
|
copy_to_fd (from, tofd);
|
|
if (close (tofd) != 0)
|
|
--
|
|
cgit v1.0-41-gc330
|
|
|