Doug / smarc-fsl-linux-kernel

12 Sep, 2013

1 commit

  • 96d0df79f   proc: make proc_fd_permission() thread-friendly ... Browse Code »

    proc_fd_permission() says "process can still access /proc/self/fd after it
    has executed a setuid()", but the "task_pid() = proc_pid() check only
    helps if the task is group leader, /proc/self points to
    /proc/.

    Change this check to use task_tgid() so that the whole thread group can
    access its /proc/self/fd or /proc//fd.

    Notes:
    - CLONE_THREAD does not require CLONE_FILES so task->files
    can differ, but I don't think this can lead to any security
    problem. And this matches same_thread_group() in
    __ptrace_may_access().

    - /proc/self should probably point to /proc/, but
    it is too late to change the rules. Perhaps it makes sense
    to add /proc/thread though.

    Test-case:

    void *tfunc(void *arg)
    {
    assert(opendir("/proc/self/fd"));
    return NULL;
    }

    int main(void)
    {
    pthread_t t;
    pthread_create(&t, NULL, tfunc, NULL);
    pthread_join(t, NULL);
    return 0;
    }

    fails if, say, this executable is not readable and suid_dumpable = 0.

    Signed-off-by: Oleg Nesterov
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Oleg Nesterov
     

25 Aug, 2013

1 commit

29 Jun, 2013

2 commits

18 Dec, 2012

1 commit

  • 55985dd72   procfs: add ability to plug in auxiliary fdinfo providers ... Browse Code »

    This patch brings ability to print out auxiliary data associated with
    file in procfs interface /proc/pid/fdinfo/fd.

    In particular further patches make eventfd, evenpoll, signalfd and
    fsnotify to print additional information complete enough to restore
    these objects after checkpoint.

    To simplify the code we add show_fdinfo callback inside struct
    file_operations (as Al and Pavel are proposing).

    Signed-off-by: Cyrill Gorcunov
    Acked-by: Pavel Emelyanov
    Cc: Oleg Nesterov
    Cc: Andrey Vagin
    Cc: Al Viro
    Cc: Alexey Dobriyan
    Cc: James Bottomley
    Cc: "Aneesh Kumar K.V"
    Cc: Alexey Dobriyan
    Cc: Matthew Helsley
    Cc: "J. Bruce Fields"
    Cc: "Aneesh Kumar K.V"
    Cc: Tvrtko Ursulin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Cyrill Gorcunov
     

27 Sep, 2012

3 commits