Description of problem: Linux 2.4.x and the SLES9/ia64 kernels have a floating point leak. This is because the context switch code checks just the psr.mfh bit and doesn't look at who the FPH owner is. This allows a malicious program to set the MFH bit and look at the registers of another possibly sensitive process. Version-Release number of selected component (if applicable): 2.4.21-12.EL. How reproducible: Run N (= number of cpus) copies of the program secret and one copy of the program check.
Created attachment 100687 [details] Lazy FP leak fix This patch fixes the issue.
Created attachment 100688 [details] secret.c
Created attachment 100689 [details] check.c
*** Bug 126126 has been marked as a duplicate of this bug. ***
A fix for this problem has just been committed to the RHEL3 E5 patch pool this evening (in kernel version 2.4.21-27.0.1.EL).
A fix for this problem has also been committed to the RHEL3 U5 patch pool this evening (in kernel version 2.4.21-27.4.EL).
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. http://rhn.redhat.com/errata/RHSA-2004-689.html