From: NeilBrown Date: Thu, 13 Dec 2012 04:14:36 +0000 (+1100) Subject: NFS: avoid NULL dereference in nfs_destroy_server X-Git-Tag: v3.8-rc1~72^2~12 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f259613a1e4b44a0cf85a5dafd931be96ee7c9e5;p=pandora-kernel.git NFS: avoid NULL dereference in nfs_destroy_server In rare circumstances, nfs_clone_server() of a v2 or v3 server can get an error between setting server->destory (to nfs_destroy_server), and calling nfs_start_lockd (which will set server->nlm_host). If this happens, nfs_clone_server will call nfs_free_server which will call nfs_destroy_server and thence nlmclnt_done(NULL). This causes the NULL to be dereferenced. So add a guard to only call nlmclnt_done() if ->nlm_host is not NULL. The other guards there are irrelevant as nlm_host can only be non-NULL if one of these flags are set - so remove those tests. (Thanks to Trond for this suggestion). This is suitable for any stable kernel since 2.6.25. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- Reading git-diff-tree failed