From patchwork Thu Nov 9 16:14:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Djalal Harouni X-Patchwork-Id: 10051213 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 27B5F603FA for ; Thu, 9 Nov 2017 16:15:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1A5EB2AFBD for ; Thu, 9 Nov 2017 16:15:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0EFA72AFC0; Thu, 9 Nov 2017 16:15:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 5AE432AFBD for ; Thu, 9 Nov 2017 16:15:23 +0000 (UTC) Received: (qmail 5367 invoked by uid 550); 9 Nov 2017 16:14:39 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 5219 invoked from network); 9 Nov 2017 16:14:36 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=6B9x6W5lf1dUlALYg5vuda+b3N7UnIrUA7f5CkgkolQ=; b=G1ho3AbGqeo7QWYE4Dw2JO972I+slWuqGkfrB1Dmi9UCqW9dS2ha54+VAaEXcz06Sa AWU8K8hsEaBn29E5o1wbfqcNzE33QUsh7CncSns7fKKDVd7CMLBftSVTirISCm7Lx9wX LwXu0tdvfnMuSNFndOHcq8mcYmUWsKWKMrOEyd1g93I1iMd/vqaKjMCipagElp3rxl2b 3uqtnWsLSEXEzgtc2jbcCs80Qjggs5yvHRO3E+Er5C1Ye/8j10HDFstUv3+9/23oTd8/ +KjJq3vd3mf3TSs3E+BxNmmgvdkiFGIA3FTkZvhY/brg4jP/ukATn23S4gcYWeaStWsL D+5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=6B9x6W5lf1dUlALYg5vuda+b3N7UnIrUA7f5CkgkolQ=; b=sjVCBw3skHGGdLcwu59+y/WxDJvXQBxNsaBoZtvLqya/XKiWmLRdII6xkzVNxJMoD8 jmth7X/qTYRwL7ZscFdqoGsYES8M92SeD8ucBFgkdNHYDLED6LxmfXNU2E5xP08yVI/N 3xUm7uza6DIfllGS39pkWfIB+RD4AkwGWrNWmwysPyf/5ctR63xM4SkgZIphElyzNSea q/lvrB2S+mS4p3xTnG2ZYR9kokPfO16nqOMHimJAr2e7F8RPeWCSdMJdtcPy0l46FCJY SG+yO/ETzE2HBuqRxnC7oNWGVy0NVcqyk3R7+ucoY6u+cTWbVTw0kapC4qLwO4X/CFjb 3Gng== X-Gm-Message-State: AJaThX7ht3mUpQKAHOPtFhyd9ZQMzX2u2E7YjR4mW9jOSYB2oox0VPGJ qdmc7WkrC/J7mff4g7Bwcmw= X-Google-Smtp-Source: ABhQp+R3x8Qt5nEob6e93ZZDBjZU1/Ys1uqmM8GK1xaaQaEHDvOnaU40Ln9zY0F8GTqe6BmrqvDhmw== X-Received: by 10.80.159.168 with SMTP id c37mr1390873edf.46.1510244065043; Thu, 09 Nov 2017 08:14:25 -0800 (PST) From: Djalal Harouni To: Kees Cook , Alexey Gladkov , Andy Lutomirski , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org Cc: Greg Kroah-Hartman , Alexander Viro , Akinobu Mita , me@tobin.cc, Oleg Nesterov , Jeff Layton , Ingo Molnar , Alexey Dobriyan , ebiederm@xmission.com, Linus Torvalds , Daniel Micay , Jonathan Corbet , bfields@fieldses.org, Stephen Rothwell , solar@openwall.com, Djalal Harouni Date: Thu, 9 Nov 2017 17:14:01 +0100 Message-Id: <1510244046-3256-3-git-send-email-tixxdz@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1510244046-3256-1-git-send-email-tixxdz@gmail.com> References: <1510244046-3256-1-git-send-email-tixxdz@gmail.com> Subject: [kernel-hardening] [PATCH RFC v3 2/7] proc: move /proc/{self|thread-self} dentries to proc_fs_info X-Virus-Scanned: ClamAV using ClamSMTP This is a preparation patch that moves /proc/{self|thread-self} dentries to be stored inside procfs proc_fs_info struct instead of making them per PID namespace. Since we want to support multiple procfs instances we need to make sure that these dentries are also per-superblock instead of per-pidns, and we want to make sure that unmounting a private procfs won't clash with other procfs mounts. Cc: Kees Cook Cc: Greg Kroah-Hartman Suggested-by: Andy Lutomirski Signed-off-by: Alexey Gladkov Signed-off-by: Djalal Harouni --- fs/proc/base.c | 4 ++-- fs/proc/root.c | 8 ++++---- fs/proc/self.c | 3 +-- fs/proc/thread_self.c | 5 ++--- include/linux/pid_namespace.h | 4 +--- include/linux/proc_fs.h | 2 ++ 6 files changed, 12 insertions(+), 14 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 5fc2006..0d9b4214 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3214,13 +3214,13 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) return 0; if (pos == TGID_OFFSET - 2) { - struct inode *inode = d_inode(ns->proc_self); + struct inode *inode = d_inode(fs_info->proc_self); if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) return 0; ctx->pos = pos = pos + 1; } if (pos == TGID_OFFSET - 1) { - struct inode *inode = d_inode(ns->proc_thread_self); + struct inode *inode = d_inode(fs_info->proc_thread_self); if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) return 0; ctx->pos = pos = pos + 1; diff --git a/fs/proc/root.c b/fs/proc/root.c index 43e2639..b225ae5 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -166,10 +166,10 @@ static void proc_kill_sb(struct super_block *sb) struct proc_fs_info *fs_info = proc_sb(sb); struct pid_namespace *ns = fs_info->pid_ns; - if (ns->proc_self) - dput(ns->proc_self); - if (ns->proc_thread_self) - dput(ns->proc_thread_self); + if (fs_info->proc_self) + dput(fs_info->proc_self); + if (fs_info->proc_thread_self) + dput(fs_info->proc_thread_self); kill_anon_super(sb); put_pid_ns(ns); kfree(fs_info); diff --git a/fs/proc/self.c b/fs/proc/self.c index f773301..8a67cf0 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -37,7 +37,6 @@ int proc_setup_self(struct super_block *s) { struct inode *root_inode = d_inode(s->s_root); struct proc_fs_info *fs_info = proc_sb(s); - struct pid_namespace *ns = fs_info->pid_ns; struct dentry *self; inode_lock(root_inode); @@ -64,7 +63,7 @@ int proc_setup_self(struct super_block *s) pr_err("proc_fill_super: can't allocate /proc/self\n"); return PTR_ERR(self); } - ns->proc_self = self; + fs_info->proc_self = self; return 0; } diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c index 578887b..6e3225f 100644 --- a/fs/proc/thread_self.c +++ b/fs/proc/thread_self.c @@ -37,7 +37,6 @@ static unsigned thread_self_inum; int proc_setup_thread_self(struct super_block *s) { struct proc_fs_info *fs_info = proc_sb(s); - struct pid_namespace *ns = fs_info->pid_ns; struct inode *root_inode = d_inode(s->s_root); struct dentry *thread_self; @@ -62,10 +61,10 @@ int proc_setup_thread_self(struct super_block *s) } inode_unlock(root_inode); if (IS_ERR(thread_self)) { - pr_err("proc_fill_super: can't allocate /proc/thread_self\n"); + pr_err("proc_fill_super: can't allocate /proc/thread-self\n"); return PTR_ERR(thread_self); } - ns->proc_thread_self = thread_self; + fs_info->proc_thread_self = thread_self; return 0; } diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 49538b1..f91a8bf 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -31,9 +31,7 @@ struct pid_namespace { unsigned int level; struct pid_namespace *parent; #ifdef CONFIG_PROC_FS - struct vfsmount *proc_mnt; - struct dentry *proc_self; - struct dentry *proc_thread_self; + struct vfsmount *proc_mnt; /* Internal proc mounted during each new pidns */ #endif #ifdef CONFIG_BSD_PROCESS_ACCT struct fs_pin *bacct; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 9a3f6e9..8f89069 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -10,6 +10,8 @@ struct proc_fs_info { struct pid_namespace *pid_ns; + struct dentry *proc_self; /* For /proc/self/ */ + struct dentry *proc_thread_self; /* For /proc/thread-self/ */ }; struct proc_dir_entry;