Ubuntu
glibc package

  1. Bug #201673
  2. Comment #23

Comment 23 for bug 201673

Revision history for this message
Bremm (bremm) wrote : Re: Hardy: "invalid pointer: 0xb7ef4b70" no program will start.

People are concerned about 'sudo' and MALLOC_CHECK_ variable. Anybody could run anything exporting it with "=1", but suid and sgid binaries don't work with it.

From `info malloc`:

There is one problem with `MALLOC_CHECK_': in SUID or SGID binaries it could possibly be exploited since diverging from the normal programs behavior it now writes something to the standard error descriptor. Therefore the use of MALLOC_CHECK_' is disabled by default for SUID and SGID binaries. It can be enabled again by the system administrator by adding a file `/etc/suid-debug' (the content is not important it could be empty).

It means I could 'touch /etc/suid-debug'. FYI: this bug caught me too; I'm an idiot, because my root has no password. lol