diff mbox series

[v3,10/12] cachefiles: Set object to close if ondemand_id < 0 in copen

Message ID 20240522114308.2402121-11-libaokun@huaweicloud.com (mailing list archive)
State Accepted
Headers show
Series cachefiles: some bugfixes and cleanups for ondemand requests | expand

Commit Message

Baokun Li May 22, 2024, 11:43 a.m. UTC 
From: Zizhi Wo <wozizhi@huawei.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@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jia Zhu <zhujia.zj@bytedance.com>
---
 fs/cachefiles/ondemand.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

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;
 }