Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933028AbcDDXmt (ORCPT ); Mon, 4 Apr 2016 19:42:49 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:35164 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932807AbcDDX2d (ORCPT ); Mon, 4 Apr 2016 19:28:33 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "J . Bruce Fields" , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 53/97] nfsd: fix deadlock secinfo+readdir compound Date: Mon, 4 Apr 2016 16:26:17 -0700 Message-Id: <1459812421-933-54-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1459812421-933-1-git-send-email-kamal@canonical.com> References: <1459812421-933-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1186 Lines: 36 3.13.11-ckt38 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: "J. Bruce Fields" commit 2f6fc056e899bd0144a08da5cacaecbe8997cd74 upstream. nfsd_lookup_dentry exits with the parent filehandle locked. fh_put also unlocks if necessary (nfsd filehandle locking is probably too lenient), so it gets unlocked eventually, but if the following op in the compound needs to lock it again, we can deadlock. A fuzzer ran into this; normal clients don't send a secinfo followed by a readdir in the same compound. Signed-off-by: J. Bruce Fields Signed-off-by: Kamal Mostafa --- fs/nfsd/nfs4proc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 25024d5..9cdd0b2 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -877,6 +877,7 @@ nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, &exp, &dentry); if (err) return err; + fh_unlock(&cstate->current_fh); if (dentry->d_inode == NULL) { exp_put(exp); err = nfserr_noent; -- 2.7.4