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    Subject[PATCH] nfs: Fix NFS v4 client handling of MAY_EXEC in nfs_permission.
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    Sorry for the resend, got lkml address wrong...

    The problem is that permission checking is skipped if atomic open is
    possible, but when exec opens a file, it just opens it O_READONLY which
    means EXEC permission will not be checked at that time.

    This problem is observed by the following sequence (executed as root):

    mount -t nfs4 server:/ /mnt4
    echo "ls" >/mnt4/foo
    chmod 744 /mnt4/foo
    su guest -c "mnt4/foo"

    Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
    ---
    fs/nfs/dir.c | 3 ++-
    1 files changed, 2 insertions(+), 1 deletions(-)

    diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
    index 370b190..89f98e9 100644
    --- a/fs/nfs/dir.c
    +++ b/fs/nfs/dir.c
    @@ -1943,7 +1943,8 @@ int nfs_permission(struct inode *inode, int mask)
    case S_IFREG:
    /* NFSv4 has atomic_open... */
    if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
    - && (mask & MAY_OPEN))
    + && (mask & MAY_OPEN)
    + && !(mask & MAY_EXEC))
    goto out;
    break;
    case S_IFDIR:


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