From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) (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 DB36517BA3; Sat, 9 Nov 2024 02:28:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.35 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731119339; cv=none; b=Jaaqf74DjXN8a0qsISywH+4eV4I5wb9IMz2bF4tDCoQZVJnDtoeC1UaVnPtlRkwOV4iIbxcXoXtbnbm2qZpGGjkcAqqfu7MSqpRKMyuuUnukdeQC6cn2gvpOh5+MF3oa7wqCfYbOW/bSuVoltvdatXzFN5UWRbfbzkETgASegNU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731119339; c=relaxed/simple; bh=wvFd1tZmndC7o8xnNugPRtmTmqP0DzsUqnLZ0/EnKjo=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=R7T1nzqzVXp8DmLfd30GsL8frCAtLh9KT94gwG2Gf2DXsWoq3AZjqaYxka0Woww09idPXqBAiIZwhBA/1TF1uGbNeaonl0y2Pj9e29JJmzd38FCWAfSaXtlBXHyoAM4zTn28bP9lJl+PjZkfJUKyxsqHAc0gI+sK47/jJSAsk68= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.35 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4XlfpH2kV2z1SDYT; Sat, 9 Nov 2024 10:27:03 +0800 (CST) Received: from kwepemf100006.china.huawei.com (unknown [7.202.181.220]) by mail.maildlp.com (Postfix) with ESMTPS id 698971400DA; Sat, 9 Nov 2024 10:28:48 +0800 (CST) Received: from [10.174.177.210] (10.174.177.210) by kwepemf100006.china.huawei.com (7.202.181.220) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 9 Nov 2024 10:28:47 +0800 Message-ID: Date: Sat, 9 Nov 2024 10:28:46 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.5.1 Subject: Re: [PATCH] nfsd: set acl_access/acl_default after getting successful To: Li Lingfeng , , , , , , , , , , CC: , , , References: <20241107014705.2509463-1-lilingfeng@huaweicloud.com> From: yangerkun In-Reply-To: <20241107014705.2509463-1-lilingfeng@huaweicloud.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemf100006.china.huawei.com (7.202.181.220) LGTM Reviewed-by: Yang Erkun Besides, nfsacld_proc_getacl should fix too. 在 2024/11/7 9:47, Li Lingfeng 写道: > If getting acl_default fails, acl_access and acl_default will be released > simultaneously. However, acl_access will still retain a pointer pointing > to the released posix_acl, which will trigger a WARNING in > nfs3svc_release_getacl like this: > > ------------[ cut here ]------------ > refcount_t: underflow; use-after-free. > WARNING: CPU: 26 PID: 3199 at lib/refcount.c:28 > refcount_warn_saturate+0xb5/0x170 > Modules linked in: > CPU: 26 UID: 0 PID: 3199 Comm: nfsd Not tainted > 6.12.0-rc6-00079-g04ae226af01f-dirty #8 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > 1.16.1-2.fc37 04/01/2014 > RIP: 0010:refcount_warn_saturate+0xb5/0x170 > Code: cc cc 0f b6 1d b3 20 a5 03 80 fb 01 0f 87 65 48 d8 00 83 e3 01 75 > e4 48 c7 c7 c0 3b 9b 85 c6 05 97 20 a5 03 01 e8 fb 3e 30 ff <0f> 0b eb > cd 0f b6 1d 8a3 > RSP: 0018:ffffc90008637cd8 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff83904fde > RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88871ed36380 > RBP: ffff888158beeb40 R08: 0000000000000001 R09: fffff520010c6f56 > R10: ffffc90008637ab7 R11: 0000000000000001 R12: 0000000000000001 > R13: ffff888140e77400 R14: ffff888140e77408 R15: ffffffff858b42c0 > FS: 0000000000000000(0000) GS:ffff88871ed00000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000562384d32158 CR3: 000000055cc6a000 CR4: 00000000000006f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > ? refcount_warn_saturate+0xb5/0x170 > ? __warn+0xa5/0x140 > ? refcount_warn_saturate+0xb5/0x170 > ? report_bug+0x1b1/0x1e0 > ? handle_bug+0x53/0xa0 > ? exc_invalid_op+0x17/0x40 > ? asm_exc_invalid_op+0x1a/0x20 > ? tick_nohz_tick_stopped+0x1e/0x40 > ? refcount_warn_saturate+0xb5/0x170 > ? refcount_warn_saturate+0xb5/0x170 > nfs3svc_release_getacl+0xc9/0xe0 > svc_process_common+0x5db/0xb60 > ? __pfx_svc_process_common+0x10/0x10 > ? __rcu_read_unlock+0x69/0xa0 > ? __pfx_nfsd_dispatch+0x10/0x10 > ? svc_xprt_received+0xa1/0x120 > ? xdr_init_decode+0x11d/0x190 > svc_process+0x2a7/0x330 > svc_handle_xprt+0x69d/0x940 > svc_recv+0x180/0x2d0 > nfsd+0x168/0x200 > ? __pfx_nfsd+0x10/0x10 > kthread+0x1a2/0x1e0 > ? kthread+0xf4/0x1e0 > ? __pfx_kthread+0x10/0x10 > ret_from_fork+0x34/0x60 > ? __pfx_kthread+0x10/0x10 > ret_from_fork_asm+0x1a/0x30 > > Kernel panic - not syncing: kernel: panic_on_warn set ... > > Clear acl_access/acl_default first and set both of them only when both > ACLs are successfully obtained. > > Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") > Signed-off-by: Li Lingfeng > --- > fs/nfsd/nfs3acl.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c > index 5e34e98db969..17579a032a5b 100644 > --- a/fs/nfsd/nfs3acl.c > +++ b/fs/nfsd/nfs3acl.c > @@ -29,10 +29,12 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) > { > struct nfsd3_getaclargs *argp = rqstp->rq_argp; > struct nfsd3_getaclres *resp = rqstp->rq_resp; > - struct posix_acl *acl; > + struct posix_acl *acl = NULL, *dacl = NULL; > struct inode *inode; > svc_fh *fh; > > + resp->acl_access = NULL; > + resp->acl_default = NULL; > fh = fh_copy(&resp->fh, &argp->fh); > resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP); > if (resp->status != nfs_ok) > @@ -56,19 +58,19 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) > resp->status = nfserrno(PTR_ERR(acl)); > goto fail; > } > - resp->acl_access = acl; > } > if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) { > /* Check how Solaris handles requests for the Default ACL > of a non-directory! */ > - acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); > - if (IS_ERR(acl)) { > - resp->status = nfserrno(PTR_ERR(acl)); > + dacl = get_inode_acl(inode, ACL_TYPE_DEFAULT); > + if (IS_ERR(dacl)) { > + resp->status = nfserrno(PTR_ERR(dacl)); > goto fail; > } > - resp->acl_default = acl; > } > > + resp->acl_access = acl; > + resp->acl_default = dacl; > /* resp->acl_{access,default} are released in nfs3svc_release_getacl. */ > out: > return rpc_success;