From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0F0AC6FA1 for ; Mon, 3 Apr 2023 14:27:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88ADEC4339B; Mon, 3 Apr 2023 14:27:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680532039; bh=FbWs3/rnsgWgG4PG1OBE6yvXyVbm/3yff3q5d1C6b+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C9oFyz1oANotCrkVHnrrRaiu5/rbgQGnkcqgFrzTf4fL8XJwNdTi3P17FcMzCtb2j F2LP1eKWvS1FS7A+cwv8gIyGaMokk0P+bZhGtQgXk93M1fXePZmpEdty4iKsSvXLPA 25+hYA55bdUqaAmmMzE5h8mtafyJPS1Ac1Sg4Fvk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xingyuan Mo , Dai Ngo , Chuck Lever , Ovidiu Panait Subject: [PATCH 5.10 103/173] NFSD: fix use-after-free in __nfs42_ssc_open() Date: Mon, 3 Apr 2023 16:08:38 +0200 Message-Id: <20230403140417.773920681@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140414.174516815@linuxfoundation.org> References: <20230403140414.174516815@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Dai Ngo commit 75333d48f92256a0dec91dbf07835e804fc411c0 upstream. Problem caused by source's vfsmount being unmounted but remains on the delayed unmount list. This happens when nfs42_ssc_open() return errors. Fixed by removing nfsd4_interssc_connect(), leave the vfsmount for the laundromat to unmount when idle time expires. We don't need to call nfs_do_sb_deactive when nfs42_ssc_open return errors since the file was not opened so nfs_server->active was not incremented. Same as in nfsd4_copy, if we fail to launch nfsd4_do_async_copy thread then there's no need to call nfs_do_sb_deactive Reported-by: Xingyuan Mo Signed-off-by: Dai Ngo Tested-by: Xingyuan Mo Signed-off-by: Chuck Lever Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4proc.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1248,13 +1248,6 @@ out_err: return status; } -static void -nfsd4_interssc_disconnect(struct vfsmount *ss_mnt) -{ - nfs_do_sb_deactive(ss_mnt->mnt_sb); - mntput(ss_mnt); -} - /* * Verify COPY destination stateid. * @@ -1325,11 +1318,6 @@ nfsd4_cleanup_inter_ssc(struct vfsmount { } -static void -nfsd4_interssc_disconnect(struct vfsmount *ss_mnt) -{ -} - static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt, struct nfs_fh *src_fh, nfs4_stateid *stateid) @@ -1471,14 +1459,14 @@ static int nfsd4_do_async_copy(void *dat copy->nf_src = kzalloc(sizeof(struct nfsd_file), GFP_KERNEL); if (!copy->nf_src) { copy->nfserr = nfserr_serverfault; - nfsd4_interssc_disconnect(copy->ss_mnt); + /* ss_mnt will be unmounted by the laundromat */ goto do_callback; } copy->nf_src->nf_file = nfs42_ssc_open(copy->ss_mnt, ©->c_fh, ©->stateid); if (IS_ERR(copy->nf_src->nf_file)) { copy->nfserr = nfserr_offload_denied; - nfsd4_interssc_disconnect(copy->ss_mnt); + /* ss_mnt will be unmounted by the laundromat */ goto do_callback; } } @@ -1561,8 +1549,10 @@ out_err: if (async_copy) cleanup_async_copy(async_copy); status = nfserrno(-ENOMEM); - if (!copy->cp_intra) - nfsd4_interssc_disconnect(copy->ss_mnt); + /* + * source's vfsmount of inter-copy will be unmounted + * by the laundromat + */ goto out; }