201 lines
4.9 KiB
Diff
201 lines
4.9 KiB
Diff
From 4e9269a5fc1fe80a1095a92593dd85db871e1fd3 Mon Sep 17 00:00:00 2001
|
|
From: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
|
|
Date: Mon, 19 Jan 2015 23:18:30 +0100
|
|
Subject: [PATCH] Make sure symlinks don't point outside working directory
|
|
(CVE-2015-1196)
|
|
|
|
When creating symlinks from git-style patches, make sure the symlinks don't
|
|
point above the current working directory. Otherwise, a subsequent patch could
|
|
use the symlink to write outside the working directory.
|
|
|
|
* src/pch.c (symlink_target_is_valid): New function to check for valid symlink
|
|
targets.
|
|
* src/util.c (move_file): Use symlink_target_is_valid() here.
|
|
* tests/symlinks: Add valid and invalid symlink test cases.
|
|
|
|
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
|
|
|
|
Upstream-Status: Backport
|
|
|
|
---
|
|
NEWS | 3 ++
|
|
src/pch.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
src/pch.h | 1 +
|
|
src/util.c | 7 +++++++
|
|
tests/symlinks | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
5 files changed, 117 insertions(+)
|
|
|
|
diff --git a/NEWS b/NEWS
|
|
index 42afed7..d3f1c2d 100644
|
|
--- a/NEWS
|
|
+++ b/NEWS
|
|
@@ -1,3 +1,6 @@
|
|
+* With git-style patches, symlinks that point outside the working directory
|
|
+ will no longer be created.
|
|
+
|
|
Changes in version 2.7.1:
|
|
|
|
* Two critical bug fixes in the "diff --git" format support.
|
|
diff --git a/src/pch.c b/src/pch.c
|
|
index 55e1504..f05ef83 100644
|
|
--- a/src/pch.c
|
|
+++ b/src/pch.c
|
|
@@ -454,6 +454,60 @@ name_is_valid (char const *name)
|
|
return is_valid;
|
|
}
|
|
|
|
+bool
|
|
+symlink_target_is_valid (char const *target, char const *to)
|
|
+{
|
|
+ bool is_valid;
|
|
+
|
|
+ if (IS_ABSOLUTE_FILE_NAME (to))
|
|
+ is_valid = true;
|
|
+ else if (IS_ABSOLUTE_FILE_NAME (target))
|
|
+ is_valid = false;
|
|
+ else
|
|
+ {
|
|
+ unsigned int depth = 0;
|
|
+ char const *t;
|
|
+
|
|
+ is_valid = true;
|
|
+ t = to;
|
|
+ while (*t)
|
|
+ {
|
|
+ while (*t && ! ISSLASH (*t))
|
|
+ t++;
|
|
+ if (ISSLASH (*t))
|
|
+ {
|
|
+ while (ISSLASH (*t))
|
|
+ t++;
|
|
+ depth++;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ t = target;
|
|
+ while (*t)
|
|
+ {
|
|
+ if (*t == '.' && *++t == '.' && (! *++t || ISSLASH (*t)))
|
|
+ {
|
|
+ if (! depth--)
|
|
+ {
|
|
+ is_valid = false;
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+ else
|
|
+ {
|
|
+ while (*t && ! ISSLASH (*t))
|
|
+ t++;
|
|
+ depth++;
|
|
+ }
|
|
+ while (ISSLASH (*t))
|
|
+ t++;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ /* Allow any symlink target if we are in the filesystem root. */
|
|
+ return is_valid || cwd_is_root (to);
|
|
+}
|
|
+
|
|
/* Determine what kind of diff is in the remaining part of the patch file. */
|
|
|
|
static enum diff
|
|
diff --git a/src/pch.h b/src/pch.h
|
|
index 0c7ff62..58861b0 100644
|
|
--- a/src/pch.h
|
|
+++ b/src/pch.h
|
|
@@ -37,6 +37,7 @@ bool pch_write_line (lin, FILE *);
|
|
bool there_is_another_patch (bool, mode_t *);
|
|
char *pfetch (lin) _GL_ATTRIBUTE_PURE;
|
|
char pch_char (lin) _GL_ATTRIBUTE_PURE;
|
|
+bool symlink_target_is_valid (char const *, char const *);
|
|
int another_hunk (enum diff, bool);
|
|
int pch_says_nonexistent (bool) _GL_ATTRIBUTE_PURE;
|
|
size_t pch_line_len (lin) _GL_ATTRIBUTE_PURE;
|
|
diff --git a/src/util.c b/src/util.c
|
|
index 66ae90f..636eded 100644
|
|
--- a/src/util.c
|
|
+++ b/src/util.c
|
|
@@ -470,6 +470,13 @@ move_file (char const *from, bool *from_needs_removal,
|
|
read_fatal ();
|
|
buffer[size] = 0;
|
|
|
|
+ if (! symlink_target_is_valid (buffer, to))
|
|
+ {
|
|
+ fprintf (stderr, "symbolic link target '%s' is invalid\n",
|
|
+ buffer);
|
|
+ fatal_exit (0);
|
|
+ }
|
|
+
|
|
if (! backup)
|
|
{
|
|
if (unlink (to) == 0)
|
|
diff --git a/tests/symlinks b/tests/symlinks
|
|
index 96626b3..6211026 100644
|
|
--- a/tests/symlinks
|
|
+++ b/tests/symlinks
|
|
@@ -146,6 +146,59 @@ ncheck 'test ! -L symlink'
|
|
|
|
# --------------------------------------------------------------
|
|
|
|
+# Patch should not create symlinks which point outside the working directory.
|
|
+
|
|
+cat > symlink-target.diff <<EOF
|
|
+diff --git a/dir/foo b/dir/foo
|
|
+new file mode 120000
|
|
+index 0000000..cad2309
|
|
+--- /dev/null
|
|
++++ b/dir/foo
|
|
+@@ -0,0 +1 @@
|
|
++../foo
|
|
+\ No newline at end of file
|
|
+EOF
|
|
+
|
|
+check 'patch -p1 < symlink-target.diff || echo "Status: $?"' <<EOF
|
|
+patching symbolic link dir/foo
|
|
+EOF
|
|
+
|
|
+cat > bad-symlink-target1.diff <<EOF
|
|
+diff --git a/bar b/bar
|
|
+new file mode 120000
|
|
+index 0000000..cad2309
|
|
+--- /dev/null
|
|
++++ b/bar
|
|
+@@ -0,0 +1 @@
|
|
++/bar
|
|
+\ No newline at end of file
|
|
+EOF
|
|
+
|
|
+check 'patch -p1 < bad-symlink-target1.diff || echo "Status: $?"' <<EOF
|
|
+patching symbolic link bar
|
|
+symbolic link target '/bar' is invalid
|
|
+Status: 2
|
|
+EOF
|
|
+
|
|
+cat > bad-symlink-target2.diff <<EOF
|
|
+diff --git a/baz b/baz
|
|
+new file mode 120000
|
|
+index 0000000..cad2309
|
|
+--- /dev/null
|
|
++++ b/baz
|
|
+@@ -0,0 +1 @@
|
|
++../baz
|
|
+\ No newline at end of file
|
|
+EOF
|
|
+
|
|
+check 'patch -p1 < bad-symlink-target2.diff || echo "Status: $?"' <<EOF
|
|
+patching symbolic link baz
|
|
+symbolic link target '../baz' is invalid
|
|
+Status: 2
|
|
+EOF
|
|
+
|
|
+# --------------------------------------------------------------
|
|
+
|
|
# The backup file of a new symlink is an empty regular file.
|
|
|
|
check 'patch -p1 --backup < create-symlink.diff || echo "Status: $?"' <<EOF
|
|
--
|
|
2.1.4
|
|
|