• Eric W. Biederman's avatar
    exec: Ensure mm->user_ns contains the execed files · b35f34f6
    Eric W. Biederman authored
    commit f84df2a6 upstream.
    
    When the user namespace support was merged the need to prevent
    ptrace from revealing the contents of an unreadable executable
    was overlooked.
    
    Correct this oversight by ensuring that the executed file
    or files are in mm->user_ns, by adjusting mm->user_ns.
    
    Use the new function privileged_wrt_inode_uidgid to see if
    the executable is a member of the user namespace, and as such
    if having CAP_SYS_PTRACE in the user namespace should allow
    tracing the executable.  If not update mm->user_ns to
    the parent user namespace until an appropriate parent is found.
    Reported-by: default avatarJann Horn <jann@thejh.net>
    Fixes: 9e4a36ec ("userns: Fail exec for suid and sgid binaries with ids outside our user namespace.")
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    b35f34f6
capability.c 13.9 KB