Red Hat Bugzilla – Bug 213567
Access to unmapped vmalloc pages when reading proc/kcore
Last modified: 2007-11-30 17:06:55 EST
While testing patches for BZ #14766 I found that 2.1 crashes reliably when more
than one process reads /proc/kcore:
$ while true; do cat /proc/kcore > /tmp/kcore; done&
$ while true; do cat /proc/kcore > /dev/null; done&
Derry, RHEL3, and later don't exhibit this problem.
Created attachment 140058 [details]
Don't use vmalloc in proc_file_read().
I couldn't recreate the crash with e.70, however I have verified that the fix is
in as part of linux-2.4.26-updates.patch and that patch is being applied in e.71.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.