Bug 530269 (CVE-2009-3623)

Summary: CVE-2009-3623 kernel: nfsd4: fix null dereference creating nfsv4 callback client
Product: [Other] Security Response Reporter: Eugene Teo (Security Response) <eteo>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: bhu, cebbert, davej, kyle, lgoncalv, lwang, rcvalle, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2010-12-21 19:21:48 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 531663    
Bug Blocks:    

Description Eugene Teo (Security Response) 2009-10-22 04:51:23 UTC
Quoting from upstream patch:
On setting up the callback to the client, we attempt to use the same authentication flavor the client did.  We find an rpc cred to use by calling rpcauth_lookup_credcache(), which assumes that the given authentication flavor has a credentials cache.  However, this is not required to be true--in particular, auth_null does not use one. Instead, we should call the auth's lookup_cred() method.

Without this, a client attempting to mount using nfsv4 and auth_null triggers a null dereference.

The code was introduced in upstream commit 3cef9ab2 (v2.6.31-rc1), fixed in 886e3b7f (v2.6.32-rc1), and was later replaced by 80fc015b.

Comment 1 Chuck Ebbert 2009-10-22 20:12:54 UTC
Commit 886e3b7f is also in (nfsd4-fix-null-dereference-creating-nfsv4-callback-client.patch), so no fix needed for Fedora 12.