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-rw-r--r--tools/patch/patches/050-CVE-2019-13636.patch108
1 files changed, 108 insertions, 0 deletions
diff --git a/tools/patch/patches/050-CVE-2019-13636.patch b/tools/patch/patches/050-CVE-2019-13636.patch
new file mode 100644
index 0000000000..e62c3d4175
--- /dev/null
+++ b/tools/patch/patches/050-CVE-2019-13636.patch
@@ -0,0 +1,108 @@
+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
+