From patchwork Tue Feb 27 00:41:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 10244019 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 02D2560384 for ; Tue, 27 Feb 2018 00:43:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E4E0A2A43D for ; Tue, 27 Feb 2018 00:43:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D666D2A4EF; Tue, 27 Feb 2018 00:43:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id A9CE32A43D for ; Tue, 27 Feb 2018 00:43:25 +0000 (UTC) Received: (qmail 5998 invoked by uid 550); 27 Feb 2018 00:42:30 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 5924 invoked from network); 27 Feb 2018 00:42:29 -0000 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= To: linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= , Alexei Starovoitov , Andy Lutomirski , Arnaldo Carvalho de Melo , Casey Schaufler , Daniel Borkmann , David Drysdale , "David S . Miller" , "Eric W . Biederman" , James Morris , Jann Horn , Jonathan Corbet , Michael Kerrisk , Kees Cook , Paul Moore , Sargun Dhillon , "Serge E . Hallyn" , Shuah Khan , Tejun Heo , Thomas Graf , Tycho Andersen , Will Drewry , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, netdev@vger.kernel.org, Alexander Viro , James Morris , John Johansen , Stephen Smalley , Tetsuo Handa , linux-fsdevel@vger.kernel.org Subject: [PATCH bpf-next v8 02/11] fs, security: Add a new file access type: MAY_CHROOT Date: Tue, 27 Feb 2018 01:41:12 +0100 Message-Id: <20180227004121.3633-3-mic@digikod.net> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180227004121.3633-1-mic@digikod.net> References: <20180227004121.3633-1-mic@digikod.net> MIME-Version: 1.0 X-Antivirus: Dr.Web (R) for Unix mail servers drweb plugin ver.6.0.2.8 X-Antivirus-Code: 0x100000 X-Virus-Scanned: ClamAV using ClamSMTP For compatibility reason, MAY_CHROOT is always set with MAY_CHDIR. However, this new flag enable to differentiate a chdir form a chroot. This is needed for the Landlock LSM to be able to evaluate a new root directory. Signed-off-by: Mickaël Salaün Cc: Alexander Viro Cc: Casey Schaufler Cc: James Morris Cc: John Johansen Cc: Kees Cook Cc: Paul Moore Cc: "Serge E. Hallyn" Cc: Stephen Smalley Cc: Tetsuo Handa Cc: linux-fsdevel@vger.kernel.org --- fs/open.c | 3 ++- include/linux/fs.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/open.c b/fs/open.c index 7ea118471dce..084d147c0e96 100644 --- a/fs/open.c +++ b/fs/open.c @@ -489,7 +489,8 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename) if (error) goto out; - error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); + error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR | + MAY_CHROOT); if (error) goto dput_and_out; diff --git a/include/linux/fs.h b/include/linux/fs.h index 2a815560fda0..67c62374446c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -90,6 +90,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, #define MAY_CHDIR 0x00000040 /* called from RCU mode, don't block */ #define MAY_NOT_BLOCK 0x00000080 +#define MAY_CHROOT 0x00000100 /* * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond