Mercurial > hg
changeset 43494:5d40317d42b7
dirs: reject consecutive slashes in paths
We shouldn't ever see those, and the fuzzer go really excited that if
it gives us a 65k string with 55k slashes in it we use a lot of RAM.
This is a better fix than what I tried in D7105. It was suggested by
Yuya, and I verified it does in fact cause the fuzzer to not OOM.
This is a revision of D7234, but with the missing set of an error
added. I added a unit test of the dirs behavior because I needed to
reason more carefully about the failure modes around consecutive
slashes.
Differential Revision: https://phab.mercurial-scm.org/D7252
author | Augie Fackler <augie@google.com> |
---|---|
date | Thu, 17 Oct 2019 19:29:22 -0400 |
parents | 3a463e5e470b |
children | daade078f1f0 |
files | mercurial/cext/dirs.c mercurial/util.py tests/test-dirs.py |
diffstat | 3 files changed, 39 insertions(+), 0 deletions(-) [+] |
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--- a/mercurial/cext/dirs.c Tue Nov 05 22:56:12 2019 -0500 +++ b/mercurial/cext/dirs.c Thu Oct 17 19:29:22 2019 -0400 @@ -66,6 +66,14 @@ while ((pos = _finddir(cpath, pos - 1)) != -1) { PyObject *val; + /* Sniff for trailing slashes, a marker of an invalid input. */ + if (pos > 0 && cpath[pos - 1] == '/') { + PyErr_SetString( + PyExc_ValueError, + "found invalid consecutive slashes in path"); + goto bail; + } + key = PyBytes_FromStringAndSize(cpath, pos); if (key == NULL) goto bail;
--- a/mercurial/util.py Tue Nov 05 22:56:12 2019 -0500 +++ b/mercurial/util.py Thu Oct 17 19:29:22 2019 -0400 @@ -3515,6 +3515,10 @@ def addpath(self, path): dirs = self._dirs for base in finddirs(path): + if base.endswith(b'/'): + raise ValueError( + "found invalid consecutive slashes in path: %r" % base + ) if base in dirs: dirs[base] += 1 return
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tests/test-dirs.py Thu Oct 17 19:29:22 2019 -0400 @@ -0,0 +1,27 @@ +from __future__ import absolute_import + +import unittest + +import silenttestrunner + +from mercurial import util + + +class dirstests(unittest.TestCase): + def testdirs(self): + for case, want in [ + (b'a/a/a', [b'a', b'a/a', b'']), + (b'alpha/beta/gamma', [b'', b'alpha', b'alpha/beta']), + ]: + d = util.dirs({}) + d.addpath(case) + self.assertEqual(sorted(d), sorted(want)) + + def testinvalid(self): + with self.assertRaises(ValueError): + d = util.dirs({}) + d.addpath(b'a//b') + + +if __name__ == '__main__': + silenttestrunner.main(__name__)