From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2155) id 402EE386FC2B; Mon, 19 Apr 2021 12:55:00 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 402EE386FC2B Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Corinna Vinschen To: cygwin-cvs@sourceware.org Subject: [newlib-cygwin] Cygwin: path_conv: Try to handle native symlinks more sanely X-Act-Checkin: newlib-cygwin X-Git-Author: Corinna Vinschen X-Git-Refname: refs/heads/master X-Git-Oldrev: 183e5f0a15f44f9a1d5d69ef0ffcfcce1ce1e680 X-Git-Newrev: 456c3a46386f38887407603b2c64b7f63a4871c5 Message-Id: <20210419125500.402EE386FC2B@sourceware.org> Date: Mon, 19 Apr 2021 12:55:00 +0000 (GMT) X-BeenThere: cygwin-cvs@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Cygwin core component git logs List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 Apr 2021 12:55:00 -0000 https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=456c3a46386f38887407603b2c64b7f63a4871c5 commit 456c3a46386f38887407603b2c64b7f63a4871c5 Author: Corinna Vinschen Date: Mon Apr 19 14:49:14 2021 +0200 Cygwin: path_conv: Try to handle native symlinks more sanely For local paths, add a check if the inner path components contain native symlinks or junctions. Compare the incoming path with the path returned by NtQueryInformationFile(FileNameInformation). If they differ, there must be at least one native symlink or junction in the path. If so, treat the currently evaluated file as non-existant. This forces path_conv::check to backtrack inner path components until we eliminated all native symlinks or junctions and have a normalized path. Signed-off-by: Corinna Vinschen Diff: --- winsup/cygwin/path.cc | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc index 1d6bcbe48..2248b564b 100644 --- a/winsup/cygwin/path.cc +++ b/winsup/cygwin/path.cc @@ -3179,6 +3179,32 @@ restart: status = conv_hdl.get_finfo (h, fs.is_nfs ()); if (NT_SUCCESS (status)) fileattr = conv_hdl.get_dosattr (fs.is_nfs ()); + + /* For local paths, check if the inner path components contain + native symlinks or junctions. Compare incoming path with + path returned by NtQueryInformationFile(FileNameInformation). + If they differ, bail out as if the file doesn't exist. This + forces path_conv::check to backtrack inner path components. */ + if (!fs.is_remote_drive ()) + { + PFILE_NAME_INFORMATION pfni = (PFILE_NAME_INFORMATION) + tp.c_get (); + + if (NT_SUCCESS (NtQueryInformationFile (h, &io, pfni, NT_MAX_PATH, + FileNameInformation))) + { + UNICODE_STRING npath; + + RtlInitCountedUnicodeString (&npath, pfni->FileName, + pfni->FileNameLength); + if (!RtlEqualUnicodePathSuffix (&upath, &npath, !!ci_flag)) + { + fileattr = INVALID_FILE_ATTRIBUTES; + set_error (ENOENT); + break; + } + } + } } if (!NT_SUCCESS (status)) {