Bug 570093

Summary: kernel: NFS: Fix an Oops when truncating a file
Product: [Other] Security Response Reporter: Eugene Teo (Security Response) <eteo>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED DUPLICATE QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: lwang
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-03-03 09:35:41 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Eugene Teo (Security Response) 2010-03-03 09:34:05 UTC
Description of problem:
The VM/VFS does not allow mapping->a_ops->invalidatepage() to fail. Unfortunately, nfs_wb_page_cancel() may fail if a fatal signal occurs. Since the NFS code assumes that the page stays mapped for as long as the writeback is active, we can end up Oopsing (among other things).
    
The only safe fix here is to convert nfs_wait_on_request(), so as to make it uninterruptible (as is already the case with wait_on_page_writeback()).

Comment 1 Eugene Teo (Security Response) 2010-03-03 09:35:41 UTC
I forgot I filed this already ;)

*** This bug has been marked as a duplicate of bug 567184 ***