From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE467C4363A for ; Tue, 27 Oct 2020 09:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EF1622258 for ; Tue, 27 Oct 2020 09:21:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2509320AbgJ0JVs (ORCPT ); Tue, 27 Oct 2020 05:21:48 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:5676 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404528AbgJ0JVr (ORCPT ); Tue, 27 Oct 2020 05:21:47 -0400 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4CL5n84Sqzz15Lls; Tue, 27 Oct 2020 17:21:48 +0800 (CST) Received: from [127.0.0.1] (10.174.176.238) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Tue, 27 Oct 2020 17:21:35 +0800 Subject: Re: [PATCH] fuse: fix potential accessing NULL pointer problem in fuse_send_init() To: , CC: linfeilong , , "linux-kernel@vger.kernel.org" , lihaotian , , , References: <5e1bf70a-0c6b-89b6-dc9f-474ccfcfe597@huawei.com> From: Zhiqiang Liu Message-ID: Date: Tue, 27 Oct 2020 17:21:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <5e1bf70a-0c6b-89b6-dc9f-474ccfcfe597@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.238] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org friendly ping... On 2020/10/22 22:51, Zhiqiang Liu wrote: > > In fuse_send_init func, ia is allocated by calling kzalloc func, and > we donot check whether ia is NULL before using it. Thus, if allocating > ia fails, accessing NULL pointer problem will occur. > > Here, we will call process_init_reply func if ia is NULL. > > Fixes: 615047eff108 ("fuse: convert init to simple api") > Signed-off-by: Zhiqiang Liu > Signed-off-by: Haotian Li > --- > fs/fuse/inode.c | 161 ++++++++++++++++++++++++++---------------------- > 1 file changed, 87 insertions(+), 74 deletions(-) > > diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c > index 581329203d68..bb526d8cf5b0 100644 > --- a/fs/fuse/inode.c > +++ b/fs/fuse/inode.c > @@ -898,88 +898,97 @@ struct fuse_init_args { > static void process_init_reply(struct fuse_conn *fc, struct fuse_args *args, > int error) > { > - struct fuse_init_args *ia = container_of(args, typeof(*ia), args); > - struct fuse_init_out *arg = &ia->out; > + struct fuse_init_args *ia; > + struct fuse_init_out *arg; > + unsigned long ra_pages; > > - if (error || arg->major != FUSE_KERNEL_VERSION) > + if (!args) { > fc->conn_error = 1; > - else { > - unsigned long ra_pages; > + goto out; > + } > > - process_init_limits(fc, arg); > + ia = container_of(args, typeof(*ia), args); > + arg = &ia->out; > + if (error || arg->major != FUSE_KERNEL_VERSION) { > + fc->conn_error = 1; > + goto out_free_ia; > + } > > - if (arg->minor >= 6) { > - ra_pages = arg->max_readahead / PAGE_SIZE; > - if (arg->flags & FUSE_ASYNC_READ) > - fc->async_read = 1; > - if (!(arg->flags & FUSE_POSIX_LOCKS)) > - fc->no_lock = 1; > - if (arg->minor >= 17) { > - if (!(arg->flags & FUSE_FLOCK_LOCKS)) > - fc->no_flock = 1; > - } else { > - if (!(arg->flags & FUSE_POSIX_LOCKS)) > - fc->no_flock = 1; > - } > - if (arg->flags & FUSE_ATOMIC_O_TRUNC) > - fc->atomic_o_trunc = 1; > - if (arg->minor >= 9) { > - /* LOOKUP has dependency on proto version */ > - if (arg->flags & FUSE_EXPORT_SUPPORT) > - fc->export_support = 1; > - } > - if (arg->flags & FUSE_BIG_WRITES) > - fc->big_writes = 1; > - if (arg->flags & FUSE_DONT_MASK) > - fc->dont_mask = 1; > - if (arg->flags & FUSE_AUTO_INVAL_DATA) > - fc->auto_inval_data = 1; > - else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA) > - fc->explicit_inval_data = 1; > - if (arg->flags & FUSE_DO_READDIRPLUS) { > - fc->do_readdirplus = 1; > - if (arg->flags & FUSE_READDIRPLUS_AUTO) > - fc->readdirplus_auto = 1; > - } > - if (arg->flags & FUSE_ASYNC_DIO) > - fc->async_dio = 1; > - if (arg->flags & FUSE_WRITEBACK_CACHE) > - fc->writeback_cache = 1; > - if (arg->flags & FUSE_PARALLEL_DIROPS) > - fc->parallel_dirops = 1; > - if (arg->flags & FUSE_HANDLE_KILLPRIV) > - fc->handle_killpriv = 1; > - if (arg->time_gran && arg->time_gran <= 1000000000) > - fc->sb->s_time_gran = arg->time_gran; > - if ((arg->flags & FUSE_POSIX_ACL)) { > - fc->default_permissions = 1; > - fc->posix_acl = 1; > - fc->sb->s_xattr = fuse_acl_xattr_handlers; > - } > - if (arg->flags & FUSE_CACHE_SYMLINKS) > - fc->cache_symlinks = 1; > - if (arg->flags & FUSE_ABORT_ERROR) > - fc->abort_err = 1; > - if (arg->flags & FUSE_MAX_PAGES) { > - fc->max_pages = > - min_t(unsigned int, FUSE_MAX_MAX_PAGES, > - max_t(unsigned int, arg->max_pages, 1)); > - } > - } else { > - ra_pages = fc->max_read / PAGE_SIZE; > + process_init_limits(fc, arg); > + > + if (arg->minor >= 6) { > + ra_pages = arg->max_readahead / PAGE_SIZE; > + if (arg->flags & FUSE_ASYNC_READ) > + fc->async_read = 1; > + if (!(arg->flags & FUSE_POSIX_LOCKS)) > fc->no_lock = 1; > - fc->no_flock = 1; > + if (arg->minor >= 17) { > + if (!(arg->flags & FUSE_FLOCK_LOCKS)) > + fc->no_flock = 1; > + } else { > + if (!(arg->flags & FUSE_POSIX_LOCKS)) > + fc->no_flock = 1; > } > - > - fc->sb->s_bdi->ra_pages = > - min(fc->sb->s_bdi->ra_pages, ra_pages); > - fc->minor = arg->minor; > - fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; > - fc->max_write = max_t(unsigned, 4096, fc->max_write); > - fc->conn_init = 1; > + if (arg->flags & FUSE_ATOMIC_O_TRUNC) > + fc->atomic_o_trunc = 1; > + if (arg->minor >= 9) { > + /* LOOKUP has dependency on proto version */ > + if (arg->flags & FUSE_EXPORT_SUPPORT) > + fc->export_support = 1; > + } > + if (arg->flags & FUSE_BIG_WRITES) > + fc->big_writes = 1; > + if (arg->flags & FUSE_DONT_MASK) > + fc->dont_mask = 1; > + if (arg->flags & FUSE_AUTO_INVAL_DATA) > + fc->auto_inval_data = 1; > + else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA) > + fc->explicit_inval_data = 1; > + if (arg->flags & FUSE_DO_READDIRPLUS) { > + fc->do_readdirplus = 1; > + if (arg->flags & FUSE_READDIRPLUS_AUTO) > + fc->readdirplus_auto = 1; > + } > + if (arg->flags & FUSE_ASYNC_DIO) > + fc->async_dio = 1; > + if (arg->flags & FUSE_WRITEBACK_CACHE) > + fc->writeback_cache = 1; > + if (arg->flags & FUSE_PARALLEL_DIROPS) > + fc->parallel_dirops = 1; > + if (arg->flags & FUSE_HANDLE_KILLPRIV) > + fc->handle_killpriv = 1; > + if (arg->time_gran && arg->time_gran <= 1000000000) > + fc->sb->s_time_gran = arg->time_gran; > + if ((arg->flags & FUSE_POSIX_ACL)) { > + fc->default_permissions = 1; > + fc->posix_acl = 1; > + fc->sb->s_xattr = fuse_acl_xattr_handlers; > + } > + if (arg->flags & FUSE_CACHE_SYMLINKS) > + fc->cache_symlinks = 1; > + if (arg->flags & FUSE_ABORT_ERROR) > + fc->abort_err = 1; > + if (arg->flags & FUSE_MAX_PAGES) { > + fc->max_pages = > + min_t(unsigned int, FUSE_MAX_MAX_PAGES, > + max_t(unsigned int, arg->max_pages, 1)); > + } > + } else { > + ra_pages = fc->max_read / PAGE_SIZE; > + fc->no_lock = 1; > + fc->no_flock = 1; > } > - kfree(ia); > > + fc->sb->s_bdi->ra_pages = > + min(fc->sb->s_bdi->ra_pages, ra_pages); > + fc->minor = arg->minor; > + fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; > + fc->max_write = max_t(unsigned int, 4096, fc->max_write); > + fc->conn_init = 1; > + > +out_free_ia: > + kfree(ia); > +out: > fuse_set_initialized(fc); > wake_up_all(&fc->blocked_waitq); > } > @@ -989,6 +998,10 @@ void fuse_send_init(struct fuse_conn *fc) > struct fuse_init_args *ia; > > ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); > + if (!ia) { > + process_init_reply(fc, NULL, -ENOTCONN); > + return; > + } > > ia->in.major = FUSE_KERNEL_VERSION; > ia->in.minor = FUSE_KERNEL_MINOR_VERSION; >