From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755888Ab3AMRrX (ORCPT ); Sun, 13 Jan 2013 12:47:23 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35141 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755632Ab3AMRpt (ORCPT ); Sun, 13 Jan 2013 12:45:49 -0500 Message-Id: <20130113174300.443582270@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 13 Jan 2013 17:43:17 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Weston Andros Adamson , Trond Myklebust Subject: [ 22/49] NFS: Fix access to suid/sgid executables In-Reply-To: <20130113174255.736888844@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weston Andros Adamson commit f8d9a897d4384b77f13781ea813156568f68b83e upstream. nfs_open_permission_mask() should only check MAY_EXEC for files that are opened with __FMODE_EXEC. Also fix NFSv4 access-in-open path in a similar way -- openflags must be used because fmode will not always have FMODE_EXEC set. This patch fixes https://bugzilla.kernel.org/show_bug.cgi?id=49101 Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust Signed-off-by: Ben Hutchings --- fs/nfs/dir.c | 16 ++++++++++------ fs/nfs/nfs4proc.c | 18 +++++++++++------- 2 files changed, 21 insertions(+), 13 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 32e6c53..1b2d7eb 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2153,12 +2153,16 @@ static int nfs_open_permission_mask(int openflags) { int mask = 0; - if ((openflags & O_ACCMODE) != O_WRONLY) - mask |= MAY_READ; - if ((openflags & O_ACCMODE) != O_RDONLY) - mask |= MAY_WRITE; - if (openflags & __FMODE_EXEC) - mask |= MAY_EXEC; + if (openflags & __FMODE_EXEC) { + /* ONLY check exec rights */ + mask = MAY_EXEC; + } else { + if ((openflags & O_ACCMODE) != O_WRONLY) + mask |= MAY_READ; + if ((openflags & O_ACCMODE) != O_RDONLY) + mask |= MAY_WRITE; + } + return mask; } diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 5d864fb..cf747ef 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1626,7 +1626,8 @@ static int _nfs4_recover_proc_open(struct nfs4_opendata *data) static int nfs4_opendata_access(struct rpc_cred *cred, struct nfs4_opendata *opendata, - struct nfs4_state *state, fmode_t fmode) + struct nfs4_state *state, fmode_t fmode, + int openflags) { struct nfs_access_entry cache; u32 mask; @@ -1638,11 +1639,14 @@ static int nfs4_opendata_access(struct rpc_cred *cred, mask = 0; /* don't check MAY_WRITE - a newly created file may not have - * write mode bits, but POSIX allows the creating process to write */ - if (fmode & FMODE_READ) - mask |= MAY_READ; - if (fmode & FMODE_EXEC) - mask |= MAY_EXEC; + * write mode bits, but POSIX allows the creating process to write. + * use openflags to check for exec, because fmode won't + * always have FMODE_EXEC set when file open for exec. */ + if (openflags & __FMODE_EXEC) { + /* ONLY check for exec rights */ + mask = MAY_EXEC; + } else if (fmode & FMODE_READ) + mask = MAY_READ; cache.cred = cred; cache.jiffies = jiffies; @@ -1896,7 +1900,7 @@ static int _nfs4_do_open(struct inode *dir, if (server->caps & NFS_CAP_POSIX_LOCK) set_bit(NFS_STATE_POSIX_LOCKS, &state->flags); - status = nfs4_opendata_access(cred, opendata, state, fmode); + status = nfs4_opendata_access(cred, opendata, state, fmode, flags); if (status != 0) goto err_opendata_put;