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 0D23011C83 for ; Mon, 28 Aug 2023 10:29:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82192C433C8; Mon, 28 Aug 2023 10:29:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218540; bh=494Pv8awvThneA6wrIL2r6LFcdbRZUPPmVolF1HPVG0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nIUUQGQIa2emBATRLxXcJpIq7MVre1kpRZV9jgqkG6ozQ8oa0hwztq340BRws2o/V LA6EKs7eITybH2hL4wB+HtmGJ9Gv9k4rDYqe99VyPsnGAb1pXnMxu8frEtP0b07g/L rc4cR2c6eWr73Qu2ovTBv3fWwLrcvvecs0T+BB/g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexander Aring , David Teigland , Sasha Levin Subject: [PATCH 4.19 085/129] fs: dlm: fix mismatch of plock results from userspace Date: Mon, 28 Aug 2023 12:12:59 +0200 Message-ID: <20230828101156.470011844@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101153.030066927@linuxfoundation.org> References: <20230828101153.030066927@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Aring [ Upstream commit 57e2c2f2d94cfd551af91cedfa1af6d972487197 ] When a waiting plock request (F_SETLKW) is sent to userspace for processing (dlm_controld), the result is returned at a later time. That result could be incorrectly matched to a different waiting request in cases where the owner field is the same (e.g. different threads in a process.) This is fixed by comparing all the properties in the request and reply. The results for non-waiting plock requests are now matched based on list order because the results are returned in the same order they were sent. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Sasha Levin --- fs/dlm/plock.c | 58 +++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 45 insertions(+), 13 deletions(-) diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c index 4a5452fd87cb0..0501821182b1e 100644 --- a/fs/dlm/plock.c +++ b/fs/dlm/plock.c @@ -408,7 +408,7 @@ static ssize_t dev_read(struct file *file, char __user *u, size_t count, if (op->info.flags & DLM_PLOCK_FL_CLOSE) list_del(&op->list); else - list_move(&op->list, &recv_list); + list_move_tail(&op->list, &recv_list); memcpy(&info, &op->info, sizeof(info)); } spin_unlock(&ops_lock); @@ -446,20 +446,52 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count, if (check_version(&info)) return -EINVAL; + /* + * The results for waiting ops (SETLKW) can be returned in any + * order, so match all fields to find the op. The results for + * non-waiting ops are returned in the order that they were sent + * to userspace, so match the result with the first non-waiting op. + */ spin_lock(&ops_lock); - list_for_each_entry(iter, &recv_list, list) { - if (iter->info.fsid == info.fsid && - iter->info.number == info.number && - iter->info.owner == info.owner) { - list_del_init(&iter->list); - memcpy(&iter->info, &info, sizeof(info)); - if (iter->data) - do_callback = 1; - else - iter->done = 1; - op = iter; - break; + if (info.wait) { + list_for_each_entry(iter, &recv_list, list) { + if (iter->info.fsid == info.fsid && + iter->info.number == info.number && + iter->info.owner == info.owner && + iter->info.pid == info.pid && + iter->info.start == info.start && + iter->info.end == info.end && + iter->info.ex == info.ex && + iter->info.wait) { + op = iter; + break; + } } + } else { + list_for_each_entry(iter, &recv_list, list) { + if (!iter->info.wait) { + op = iter; + break; + } + } + } + + if (op) { + /* Sanity check that op and info match. */ + if (info.wait) + WARN_ON(op->info.optype != DLM_PLOCK_OP_LOCK); + else + WARN_ON(op->info.fsid != info.fsid || + op->info.number != info.number || + op->info.owner != info.owner || + op->info.optype != info.optype); + + list_del_init(&op->list); + memcpy(&op->info, &info, sizeof(info)); + if (op->data) + do_callback = 1; + else + op->done = 1; } spin_unlock(&ops_lock); -- 2.40.1