lkml.org 
[lkml]   [2003]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: Ptrace hole / Linux 2.2.25
    From
    Date
    Alan Cox <alan@redhat.com> writes:

    > A patch for Linux 2.4.20/Linux 2.4.21pre is attached. The patch also
    > subtly changes the PR_SET_DUMPABLE prctl. We believe this is neccessary and
    > that it will not affect any software. The functionality change is specific
    > to unusual debugging situations.

    I am concerned about this change because it will break sandboxing
    software that I have written, which uses prctl() to turn
    dumpability back on so that it can open a file, setuid(), and
    then execve() through the open file via /proc/self/fd/#. Without
    calling prctl(), the ownership of /proc/self/fd/* becomes root,
    so the process cannot exec it after it drops privileges. It uses
    prctl() in other places to get the same effect in /proc, but
    that's one of the most critical.
    --
    <blp@cs.stanford.edu> <pfaffben@msu.edu> <pfaffben@debian.org> <blp@gnu.org>
    Stanford Ph.D. Student - MSU Alumnus - Debian Maintainer - GNU Developer
    www.benpfaff.org
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:34    [W:28.494 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site