From 2e4b7239a62a0c58664bf0cf73aea951b7e046fc Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Fri, 8 Mar 2013 09:30:43 -0500 Subject: [PATCH] nfsd4: fix use-after-free of 4.1 client on connection loss Once we drop the lock here there's nothing keeping the client around: the only lock still held is the xpt_lock on this socket, but this socket no longer has any connection with the client so there's no way for other code to know we're still using the client. The solution is simple: all nfsd4_probe_callback does is set a few variables and queue some work, so there's no reason we can't just keep it under the lock. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 3e5cbfe8a967..baf314a950b8 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -761,8 +761,8 @@ static void nfsd4_conn_lost(struct svc_xpt_user *u) list_del(&c->cn_persession); free_conn(c); } - spin_unlock(&clp->cl_lock); nfsd4_probe_callback(clp); + spin_unlock(&clp->cl_lock); } static struct nfsd4_conn *alloc_conn(struct svc_rqst *rqstp, u32 flags)