From patchwork Fri Mar 4 16:14:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 12769420 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9BD08C4332F for ; Fri, 4 Mar 2022 16:13:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240670AbiCDQOm (ORCPT ); Fri, 4 Mar 2022 11:14:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240183AbiCDQOj (ORCPT ); Fri, 4 Mar 2022 11:14:39 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4F66157207; Fri, 4 Mar 2022 08:13:51 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 876C01F38A; Fri, 4 Mar 2022 16:13:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1646410430; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3iB4IVSxvoxrgPRlS4xZegvmXLYHfk7btvgwcWOpvg=; b=d2jF9WrhG5m83dax3NIdFlMlkxldqtyWg/OF7qKs/faW68IEoGLltHId6bZgIl6BzLW2sz aD9bu/qz44Kar+SaM6Ei3G2zouTnpOZ0GvwolTfCQgd815vfJ8LOe86dyGETNblhAC8fMc u6zm6N/ciO6n/+Ub+9QOB1Q/HAbjiBs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1646410430; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3iB4IVSxvoxrgPRlS4xZegvmXLYHfk7btvgwcWOpvg=; b=rJYkoa8Z8Nz0U6cYo52Y0FqpTFa1/XxmMOGsYj4KUxEIV7a8kQf9NqrNmiw2yWSJdDIrzS 7hZmItE0lNSzSFDg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1592C13B64; Fri, 4 Mar 2022 16:13:50 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id cPRhAr46ImKeRAAAMHmgww (envelope-from ); Fri, 04 Mar 2022 16:13:50 +0000 Received: from localhost (brahms.olymp [local]) by brahms.olymp (OpenSMTPD) with ESMTPA id 8db641e2; Fri, 4 Mar 2022 16:14:04 +0000 (UTC) From: =?utf-8?q?Lu=C3=ADs_Henriques?= To: Jeff Layton , Xiubo Li , Ilya Dryomov Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Lu?= =?utf-8?q?=C3=ADs_Henriques?= Subject: [PATCH 2/3] ceph: fix use-after-free in ceph_readdir Date: Fri, 4 Mar 2022 16:14:02 +0000 Message-Id: <20220304161403.19295-3-lhenriques@suse.de> In-Reply-To: <20220304161403.19295-1-lhenriques@suse.de> References: <20220304161403.19295-1-lhenriques@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org After calling ceph_mdsc_put_request() on dfi->last_readdir, this field should be set to NULL, otherwise we may end-up freeing it twince and get the following splat: refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 229 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0 ... Call Trace: ceph_readdir+0xd35/0x1460 [ceph] ? _raw_spin_unlock+0x12/0x30 ? preempt_count_add+0x73/0xa0 ? _raw_spin_unlock+0x12/0x30 ? __mark_inode_dirty+0x27c/0x3a0 iterate_dir+0x7d/0x190 __x64_sys_getdents64+0x80/0x120 ? compat_fillonedir+0x160/0x160 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Signed-off-by: Luís Henriques --- fs/ceph/dir.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 0bcb677d2199..934402f5e9e6 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -555,6 +555,7 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) le32_to_cpu(rde->inode.in->mode) >> 12)) { dout("filldir stopping us...\n"); ceph_mdsc_put_request(dfi->last_readdir); + dfi->last_readdir = NULL; err = 0; goto out; }