Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx12.netapp.com ([216.240.18.77]:17637 "EHLO mx12.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753643Ab3ACVmb (ORCPT ); Thu, 3 Jan 2013 16:42:31 -0500 From: Weston Andros Adamson To: Trond.Myklebust@netapp.com Cc: linux-nfs@vger.kernel.org, Weston Andros Adamson Subject: [PATCH] NFS: Fix access to suid/sgid executables Date: Thu, 3 Jan 2013 16:42:29 -0500 Message-Id: <1357249349-12074-1-git-send-email-dros@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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. Signed-off-by: Weston Andros Adamson --- This patch fixes https://bugzilla.kernel.org/show_bug.cgi?id=49101 Patch v2 - apply Trond's comment: only check MAY_EXEC when openflags has __FMODE_EXEC. fs/nfs/dir.c | 16 ++++++++++------ fs/nfs/nfs4proc.c | 18 ++++++++++++------ 2 files changed, 22 insertions(+), 12 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..3b70588 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; @@ -1637,12 +1638,17 @@ static int nfs4_opendata_access(struct rpc_cred *cred, return 0; mask = 0; + + /* 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; + /* 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; + else if (fmode & FMODE_READ) + mask = MAY_READ; cache.cred = cred; cache.jiffies = jiffies; @@ -1896,7 +1902,7 @@ 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; -- 1.7.9.6 (Apple Git-31.1)