• Eric W. Biederman's avatar
    autofs: Fix automounts by using current_real_cred()->uid · 069d5ac9
    Eric W. Biederman authored
    Seth Forshee reports that in 4.8-rcN some automounts are failing
    because the requesting the automount changed.
    
    The relevant call path is:
    follow_automount()
        ->d_automount
        autofs4_d_automount
           autofs4_mount_wait
               autofs4_wait
    
    In autofs4_wait wq_uid and wq_gid are set to current_uid() and
    current_gid respectively.  With follow_automount now overriding creds
    uid that we export to userspace changes and that breaks existing
    setups.
    
    To remove the regression set wq_uid and wq_gid from
    current_real_cred()->uid and current_real_cred()->gid respectively.
    This restores the current behavior as current->real_cred is identical
    to current->cred except when override creds are used.
    
    Cc: stable@vger.kernel.org
    Fixes: aeaa4a79 ("fs: Call d_automount with the filesystems creds")
    Reported-by: default avatarSeth Forshee <seth.forshee@canonical.com>
    Tested-by: default avatarSeth Forshee <seth.forshee@canonical.com>
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    069d5ac9
waitq.c 14.1 KB