From: David Drysdale <drysdale@google.com>
To: linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Kees Cook <keescook@chromium.org>,
"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Meredydd Luff <meredydd@senatehouse.org>,
Will Drewry <wad@chromium.org>,
Jorge Lucangeli Obes <jorgelo@google.com>,
Ricky Zhou <rickyz@google.com>, Lee Campbell <leecam@google.com>,
Julien Tinnes <jln@google.com>,
Mike Depinet <mdepinet@google.com>,
James Morris <james.l.morris@oracle.com>,
Andy Lutomirski <luto@amacapital.net>,
Paolo Bonzini <pbonzini@redhat.com>,
Paul Moore <paul@paul-moore.com>,
Christoph Hellwig <hch@infradead.org>,
linux-api@vger.kernel.org, linux-security-module@vger.kernel.org,
David Drysdale <drysdale@google.com>
Subject: [PATCHv2 man-pages 3/3] open.2: describe O_BENEATH flag
Date: Tue, 4 Nov 2014 09:54:44 +0000 [thread overview]
Message-ID: <1415094884-18349-4-git-send-email-drysdale@google.com> (raw)
In-Reply-To: <1415094884-18349-1-git-send-email-drysdale@google.com>
Signed-off-by: David Drysdale <drysdale@google.com>
---
man2/open.2 | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/man2/open.2 b/man2/open.2
index abc3c35b8b3a..f06edc4aa843 100644
--- a/man2/open.2
+++ b/man2/open.2
@@ -716,6 +716,31 @@ XFS support was added
.\" commit ab29743117f9f4c22ac44c13c1647fb24fb2bafe
in Linux 3.15.
.TP
+.B O_BENEATH " (since Linux 3.??)"
+Ensure that the
+.I pathname
+is beneath the current working directory (for
+.BR open (2))
+or the
+.I dirfd
+(for
+.BR openat (2)).
+If the
+.I pathname
+is absolute or contains a path component of "..", the
+.BR open ()
+fails with the error
+.BR EPERM.
+This occurs even if ".." path component would not actually
+escape the original directory; for example, a
+.I pathname
+of "subdir/../filename" would be rejected.
+Path components that are symbolic links to absolute paths, or that are
+relative paths containing a ".." component, will also cause the
+.BR open ()
+operation to fail with the error
+.BR EPERM.
+.TP
.B O_TRUNC
If the file already exists and is a regular file and the access mode allows
writing (i.e., is
@@ -976,6 +1001,13 @@ flag was specified, but the effective user ID of the caller
did not match the owner of the file and the caller was not privileged
.RB ( CAP_FOWNER ).
.TP
+.B EPERM
+The
+.B O_BENEATH
+flag was specified and the
+.I pathname
+was not beneath the relevant directory.
+.TP
.B EROFS
.I pathname
refers to a file on a read-only filesystem and write access was
--
2.1.0.rc2.206.gedb03e5
prev parent reply other threads:[~2014-11-04 10:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-04 9:54 [PATCHv2 0/3] fs: add O_BENEATH flag to openat(2) David Drysdale
2014-11-04 9:54 ` [PATCHv2 1/3] " David Drysdale
2014-11-04 9:54 ` [PATCHv2 2/3] selftests: Add test of O_BENEATH & openat(2) David Drysdale
2014-11-04 18:47 ` Kees Cook
2014-11-11 5:36 ` Dave Chinner
2014-11-21 14:19 ` David Drysdale
2014-12-12 0:05 ` Dave Chinner
2014-11-04 9:54 ` David Drysdale [this message]
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