From patchwork Sun Nov 19 22:53:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Kent X-Patchwork-Id: 13460706 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from smtp01.aussiebb.com.au (smtp01.aussiebb.com.au [IPv6:2403:5800:3:25::1001]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E4749E; Sun, 19 Nov 2023 14:53:45 -0800 (PST) Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp01.aussiebb.com.au (Postfix) with ESMTP id 6AF7F1002E8; Mon, 20 Nov 2023 09:53:40 +1100 (AEDT) X-Virus-Scanned: Debian amavisd-new at smtp01.aussiebb.com.au Received: from smtp01.aussiebb.com.au ([127.0.0.1]) by localhost (smtp01.aussiebb.com.au [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id DzoD7MaJF9yt; Mon, 20 Nov 2023 09:53:40 +1100 (AEDT) Received: by smtp01.aussiebb.com.au (Postfix, from userid 116) id 5FD251002F5; Mon, 20 Nov 2023 09:53:40 +1100 (AEDT) X-Spam-Level: Received: from donald.themaw.com (2403-580f-7fe0--101a.ip6.aussiebb.net [IPv6:2403:580f:7fe0::101a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: ian146@aussiebb.com.au) by smtp01.aussiebb.com.au (Postfix) with ESMTPSA id 957AD100282; Mon, 20 Nov 2023 09:53:38 +1100 (AEDT) From: Ian Kent To: Al Viro , Christian Brauner Cc: Bill O'Donnell , Kernel Mailing List , autofs mailing list , linux-fsdevel , Ian Kent , syzbot+662f87a8ef490f45fa64@syzkaller.appspotmail.com Subject: [PATCH v2] autofs: add: new_inode check in autofs_fill_super() Date: Mon, 20 Nov 2023 06:53:19 +0800 Message-ID: <20231119225319.331156-1-raven@themaw.net> X-Mailer: git-send-email 2.41.0 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add missing NULL check of root_inode in autofs_fill_super(). While we are at it simplify the logic by taking advantage of the VFS cleanup procedures and get rid of the goto error handling, as suggested by Al Viro. Signed-off-by: Ian Kent Cc: Al Viro Cc: Christian Brauner Cc: Bill O'Donnell Reported-by: syzbot+662f87a8ef490f45fa64@syzkaller.appspotmail.com Reviewed-by: Bill O'Donnell --- fs/autofs/inode.c | 59 ++++++++++++++++++----------------------------- 1 file changed, 22 insertions(+), 37 deletions(-) diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c index a5083d447a62..6ecf68536240 100644 --- a/fs/autofs/inode.c +++ b/fs/autofs/inode.c @@ -311,7 +311,6 @@ static int autofs_fill_super(struct super_block *s, struct fs_context *fc) struct inode *root_inode; struct dentry *root; struct autofs_info *ino; - int ret = -ENOMEM; pr_debug("starting up, sbi = %p\n", sbi); @@ -328,56 +327,42 @@ static int autofs_fill_super(struct super_block *s, struct fs_context *fc) */ ino = autofs_new_ino(sbi); if (!ino) - goto fail; + return -ENOMEM; root_inode = autofs_get_inode(s, S_IFDIR | 0755); - root_inode->i_uid = ctx->uid; - root_inode->i_gid = ctx->gid; - - root = d_make_root(root_inode); - if (!root) - goto fail_ino; - - root->d_fsdata = ino; + if (root_inode) { + root_inode->i_uid = ctx->uid; + root_inode->i_gid = ctx->gid; + root_inode->i_fop = &autofs_root_operations; + root_inode->i_op = &autofs_dir_inode_operations; + } + s->s_root = d_make_root(root_inode); + if (unlikely(!s->s_root)) { + autofs_free_ino(ino); + return -ENOMEM; + } + s->s_root->d_fsdata = ino; if (ctx->pgrp_set) { sbi->oz_pgrp = find_get_pid(ctx->pgrp); - if (!sbi->oz_pgrp) { - ret = invalf(fc, "Could not find process group %d", - ctx->pgrp); - goto fail_dput; - } - } else { + if (!sbi->oz_pgrp) + return invalf(fc, "Could not find process group %d", + ctx->pgrp); + } else sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); - } if (autofs_type_trigger(sbi->type)) - __managed_dentry_set_managed(root); - - root_inode->i_fop = &autofs_root_operations; - root_inode->i_op = &autofs_dir_inode_operations; + /* s->s_root won't be contended so there's little to + * be gained by not taking the d_lock when setting + * d_flags, even when a lot mounts are being done. + */ + managed_dentry_set_managed(s->s_root); pr_debug("pipe fd = %d, pgrp = %u\n", sbi->pipefd, pid_nr(sbi->oz_pgrp)); sbi->flags &= ~AUTOFS_SBI_CATATONIC; - - /* - * Success! Install the root dentry now to indicate completion. - */ - s->s_root = root; return 0; - - /* - * Failure ... clean up. - */ -fail_dput: - dput(root); - goto fail; -fail_ino: - autofs_free_ino(ino); -fail: - return ret; } /*