Date: Sat, 24 Jan 2004 12:52:38 -0800 (PST) From: Stephan Uphoff <ups@tree.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/61849: Possible use of kqueue_scan on stack marker while stack swapped out Message-ID: <200401242052.i0OKqcHc044309@www.freebsd.org> Resent-Message-ID: <200401242100.i0OL0TQG034805@freefall.freebsd.org>
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>Number: 61849
>Category: kern
>Synopsis: Possible use of kqueue_scan on stack marker while stack swapped out
>Confidential: no
>Severity: serious
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sat Jan 24 13:00:28 PST 2004
>Closed-Date:
>Last-Modified:
>Originator: Stephan Uphoff
>Release: current
>Organization:
>Environment:
N/A
>Description:
kqueue_scan() puts a marker element on the event list.
The marker element lives on the stack.
kqueue_scan() can block (example copyout) and its stack can
be swapped out.
The marker element might be accessed while the stack is swapped out.
>How-To-Repeat:
>Fix:
Use PROC_LOCK/PROC_UNLOCK to prevent swapping or use
non stack memory for the marker element.
>Release-Note:
>Audit-Trail:
>Unformatted:
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