linux-kernel - [PATCH v3 10/12] cachefiles: Set object to close if ondemand

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240522114308.2402121-11-libaokun@huaweicloud.com>
Date: Wed, 22 May 2024 19:43:06 +0800
From: libaokun@...weicloud.com
To: netfs@...ts.linux.dev,
	dhowells@...hat.com,
	jlayton@...nel.org
Cc: hsiangkao@...ux.alibaba.com,
	jefflexu@...ux.alibaba.com,
	zhujia.zj@...edance.com,
	linux-erofs@...ts.ozlabs.org,
	linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	libaokun@...weicloud.com,
	yangerkun@...wei.com,
	houtao1@...wei.com,
	yukuai3@...wei.com,
	wozizhi@...wei.com,
	Baokun Li <libaokun1@...wei.com>
Subject: [PATCH v3 10/12] cachefiles: Set object to close if ondemand_id < 0 in copen

From: Zizhi Wo <wozizhi@...wei.com>

If copen is maliciously called in the user mode, it may delete the request
corresponding to the random id. And the request may have not been read yet.

Note that when the object is set to reopen, the open request will be done
with the still reopen state in above case. As a result, the request
corresponding to this object is always skipped in select_req function, so
the read request is never completed and blocks other process.

Fix this issue by simply set object to close if its id < 0 in copen.

Signed-off-by: Zizhi Wo <wozizhi@...wei.com>
Signed-off-by: Baokun Li <libaokun1@...wei.com>
Acked-by: Jeff Layton <jlayton@...nel.org>
Reviewed-by: Jia Zhu <zhujia.zj@...edance.com>
---
 fs/cachefiles/ondemand.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 6f815e7c5086..922cab1a314b 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -182,6 +182,7 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
 	xas_store(&xas, NULL);
 	xa_unlock(&cache->reqs);
 
+	info = req->object->ondemand;
 	/* fail OPEN request if copen format is invalid */
 	ret = kstrtol(psize, 0, &size);
 	if (ret) {
@@ -201,7 +202,6 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
 		goto out;
 	}
 
-	info = req->object->ondemand;
 	spin_lock(&info->lock);
 	/*
 	 * The anonymous fd was closed before copen ? Fail the request.
@@ -241,6 +241,11 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
 	wake_up_all(&cache->daemon_pollwq);
 
 out:
+	spin_lock(&info->lock);
+	/* Need to set object close to avoid reopen status continuing */
+	if (info->ondemand_id == CACHEFILES_ONDEMAND_ID_CLOSED)
+		cachefiles_ondemand_set_object_close(req->object);
+	spin_unlock(&info->lock);
 	complete(&req->done);
 	return ret;
 }
-- 
2.39.2