Bug 868031

Created attachment 629686 [details]
test support program

Description of problem:

    This is a regression due to the changes in bug 667120.  I do not
    have access to that bug report so I don't know its intentions.

    The way sudo works is that it (1) sets its RLIMIT_CORE soft limit
    to zero for itself, and then (2) restores the original limit
    before exec'ing the child process.

    The problem with the bug 667120 changes were that they disabled
    the first part yet left the restoration part.  Since (1) doesn't
    run, (2) does not have the original values to restore and restores
    a zeroed out struct rlimit, forcing the hard and soft limits of
    the child to be zero.

    There is no workaround for this as a hard limit of zero allows no
    modification.

Version-Release number of selected component (if applicable):

    sudo-1.7.4p5-13.el6_3.x86_64.rpm

How reproducible:

    Always

Steps to Reproduce:

    I've attached a program that prints its RLIMIT_CORE soft and hard
    limits.  Running this with and without sudo should yield the same
    results (in absence of any PAM rules, etc).

    1. Compile test program: cc -o /tmp/rlimit rlimit.c
    2. Run directly, it will show you your RLIMIT_CORE values (if your
       values are already zero, set them to something nonzero)
    3. Run under sudo, it will always have zero cur/hard values.
  
Actual results:

    Hard-limit on RLIMIT_CORE is set to zero.

Expected results:

    RLIMIT_CORE limits unaffected.

Additional info:

Here are verbose repro steps.

Set up core limit to 1M soft, no hard limit

    $ ulimit -H -c unlimited
    $ ulimit -S -c 1024

.....................................................................
Try with OLDER version
.....................................................................

    $ rpm -q sudo
    sudo-1.7.4p5-5.el6.x86_64

Verify settings

    $ ulimit -c
    1024
    $ egrep 'Limit|core' /proc/$$/limits
    Limit                     Soft Limit   Hard Limit    Units
    Max core file size        102400000    unlimited     bytes

Run program with and without sudo, as root and as self

    $ /tmp/rlimit
    s:1048576 h:-1
    $ sudo /tmp/rlimit
    s:1048576 h:-1          <<<<<<<<<<< good
    $ sudo -u `id -nu` /tmp/rlimit
    s:1048576 h:-1          <<<<<<<<<<< good

.....................................................................
Try with NEWER version
.....................................................................

    $ rpm -q sudo
    sudo-1.7.4p5-13.el6_3.x86_64

Verify settings

    $ ulimit -c
    1024
    $ egrep 'Limit|core' /proc/$$/limits
    Limit                     Soft Limit   Hard Limit    Units
    Max core file size        102400000    unlimited     bytes

Run program with and without sudo, as root and as self

    $ /tmp/rlimit
    s:1048576 h:-1
    $ sudo /tmp/rlimit
    s:0 h:0                <<<<<<<<<<<< wrong
    $ sudo -u `id -nu` /tmp/rlimit
    s:0 h:0                <<<<<<<<<<<< wrong