Red Hat Bugzilla – Bug 146089
20050115 ptrace/kill and ptrace/dump race fixes
Last modified: 2007-11-30 17:07:15 EST
On 20050115, Roland commited a number of fixes to 2.6-bk in order to correct
races. We've not investigated the impact of these issues but they look from the
descriptions like they could lead to and unprivileged user deadlocking a system
(DoS, crash). Please let us know if this is incorrect.
1. fix coredump_wait deadlock with ptracer & tracee on shared mm
fixed=2.6-bk (20050115 cset@41e9a97cuQ7FWekabtf12Orvpfbp1w)
2. fix race between core dumping and exec with shared mm
fixed=2.6-bk (20050115 cset@41e9a98dJKJjUrTCrKsyak1DOQxQug)
3. fix exec deadlock when ptrace used inside the thread group
fixed=2.6-bk (20050115 cset@41e9a99fugWWHLAKeLYyNRl6h9RHlg)
4. clear false pending signal indication in core dump
fixed=2.6-bk (20050115 cset@41e9a9bcwYGXPK_HRWKybNR060H80g)
(Prefix cset@ with http://linux.bkbits.net:8080/linux-2.6/ for a direct link
to each fix)
Agreed, this can be deferred.
Patches confirmed in 2.6.9-6.37.EL. Moving to PROD_READY.
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.
Created attachment 120583 [details]
test case for case #3 (exec deadlock)
For regression testing, this is my test case for the #3 scenario, an exec that
leaves an unkillable stopped process.