From nobody Thu Feb 12 09:31:13 2026 Received: from mx0b-0064b401.pphosted.com (mx0b-0064b401.pphosted.com [205.220.178.238]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4FC83163; Fri, 14 Jun 2024 01:05:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.178.238 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718327132; cv=none; b=EClCJiut20856YccMVDaWtmL5rwKWpNFA0FlOiquQLmSw+ZsAFGvgO9Bu89zqLHhlaFiPH3WDRWYjukYJhH7DMBWfrvy1VQS6jXadgIamJJTUOgF9RoATTmn9iLulxMvGDd/jn9gN1IVTpJbEqU2JsUCw7OPJcJEt5uOYvw8Ldw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718327132; c=relaxed/simple; bh=PekTB8wWNvrnCvP2P/JIrxw9nxaknXwMDBljbAjXfyE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GBaCqrRobnuU852VaNknIuGiqvpvvwKRqoTmOrDcFxij5HAPpm/ZgXe79SHlC1Y17vDNBvBVcuWWyw5L7B/raF4RzqYIbzmN8JInvQHWH3Ebvgwjyvx+NnE9cj+2LLq3Ac8H65jHRKyz6Q8FHJSAEPGZma7VvXYDVB4gBjVSr8w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com; spf=pass smtp.mailfrom=windriver.com; arc=none smtp.client-ip=205.220.178.238 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=windriver.com Received: from pps.filterd (m0250812.ppops.net [127.0.0.1]) by mx0a-0064b401.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 45E0Ujcl028810; Fri, 14 Jun 2024 01:05:26 GMT Received: from ala-exchng02.corp.ad.wrs.com (ala-exchng02.wrs.com [147.11.82.254]) by mx0a-0064b401.pphosted.com (PPS) with ESMTPS id 3yme965jrj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Fri, 14 Jun 2024 01:05:25 +0000 (GMT) Received: from ALA-EXCHNG02.corp.ad.wrs.com (147.11.82.254) by ALA-EXCHNG02.corp.ad.wrs.com (147.11.82.254) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Thu, 13 Jun 2024 18:05:24 -0700 Received: from pek-lpd-ccm6.wrs.com (147.11.136.210) by ALA-EXCHNG02.corp.ad.wrs.com (147.11.82.254) with Microsoft SMTP Server id 15.1.2507.39 via Frontend Transport; Thu, 13 Jun 2024 18:05:22 -0700 From: Lizhi Xu To: CC: , , , , Subject: [PATCH] ovl: avoid deadlock in ovl_create_tmpfile Date: Fri, 14 Jun 2024 09:05:22 +0800 Message-ID: <20240614010522.2261016-1-lizhi.xu@windriver.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <000000000000871190061acd8fed@google.com> References: <000000000000871190061acd8fed@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Proofpoint-GUID: BhpMO5as8WEAVXN-nnT_laXPQq3yOLaw X-Proofpoint-ORIG-GUID: BhpMO5as8WEAVXN-nnT_laXPQq3yOLaw X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-06-13_15,2024-06-13_02,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 clxscore=1011 lowpriorityscore=0 adultscore=0 spamscore=0 suspectscore=0 phishscore=0 impostorscore=0 mlxscore=0 mlxlogscore=679 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.21.0-2405170001 definitions=main-2406140003 Content-Type: text/plain; charset="utf-8" ovl_copy_up() will retrieve sb_writers, and ovl_want_write will also retrie= ve sb_writers, adjusting the order of their execution to avoid deadlocks. Reported-by: syzbot+b778ac10fe2a0cd72517@syzkaller.appspotmail.com Signed-off-by: Lizhi Xu --- fs/overlayfs/dir.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 116f542442dd..ab65e98a1def 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -1314,10 +1314,6 @@ static int ovl_create_tmpfile(struct file *file, str= uct dentry *dentry, int flags =3D file->f_flags | OVL_OPEN_FLAGS; int err; =20 - err =3D ovl_copy_up(dentry->d_parent); - if (err) - return err; - old_cred =3D ovl_override_creds(dentry->d_sb); err =3D ovl_setup_cred_for_create(dentry, inode, mode, old_cred); if (err) @@ -1360,6 +1356,10 @@ static int ovl_tmpfile(struct mnt_idmap *idmap, stru= ct inode *dir, if (!OVL_FS(dentry->d_sb)->tmpfile) return -EOPNOTSUPP; =20 + err =3D ovl_copy_up(dentry->d_parent); + if (err) + return err; + err =3D ovl_want_write(dentry); if (err) return err; --=20 2.43.0