Bug 149591

Summary: CAN-2005-0178 tty/setsid race
Product: Red Hat Enterprise Linux 3 Reporter: Mark J. Cox <mjc>
Component: kernelAssignee: Dave Jones <davej>
Status: CLOSED NOTABUG QA Contact: Brian Brock <bbrock>
Severity: high Docs Contact:
Priority: medium    
Version: 3.0CC: petrides, pfrields, riel
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,public=20050110
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2005-02-24 11:12:33 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
Proposed patch from Debian none

Description Mark J. Cox 2005-02-24 11:07:14 UTC 
"Race condition in the setsid function in Linux before 2.6.8.1 allows
local users to cause a denial of service (crash) and possibly access
portions of kernel memory, related to TTY changes, locking, and
semaphores."

We originally believed this issue did not affect 2.4 kernels, however
this appears to be incorrect.
Comment 1 Mark J. Cox 2005-02-24 11:10:42 UTC 
Created attachment 111370 [details]
Proposed patch from Debian
Comment 2 Mark J. Cox 2005-02-24 11:12:33 UTC 
Actually, Alan said "In the 2.4 case your controlling tty is
private not thread group so a setsid() can't race because you can't
setsid in the same thread as is opening current->tty."