From: libaokun@huaweicloud.com
To: netfs@lists.linux.dev
Cc: dhowells@redhat.com, jlayton@kernel.org, zhujia.zj@bytedance.com,
jefflexu@linux.alibaba.com, linux-erofs@lists.ozlabs.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
libaokun@huaweicloud.com, Baokun Li <libaokun1@huawei.com>
Subject: [PATCH 06/12] cachefiles: add consistency check for copen/cread
Date: Wed, 24 Apr 2024 11:39:10 +0800 [thread overview]
Message-ID: <20240424033916.2748488-7-libaokun@huaweicloud.com> (raw)
In-Reply-To: <20240424033916.2748488-1-libaokun@huaweicloud.com>
From: Baokun Li <libaokun1@huawei.com>
This prevents malicious processes from completing random copen/cread
requests and crashing the system. Added checks are listed below:
* Generic, copen can only complete open requests, and cread can only
complete read requests.
* For copen, ondemand_id must not be 0, because this indicates that the
request has not been read by the daemon.
* For cread, the object corresponding to fd and req should be the same.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
---
fs/cachefiles/ondemand.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index bb94ef6a6f61..898fab68332b 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -82,12 +82,12 @@ static loff_t cachefiles_ondemand_fd_llseek(struct file *filp, loff_t pos,
}
static long cachefiles_ondemand_fd_ioctl(struct file *filp, unsigned int ioctl,
- unsigned long arg)
+ unsigned long id)
{
struct cachefiles_object *object = filp->private_data;
struct cachefiles_cache *cache = object->volume->cache;
struct cachefiles_req *req;
- unsigned long id;
+ XA_STATE(xas, &cache->reqs, id);
if (ioctl != CACHEFILES_IOC_READ_COMPLETE)
return -EINVAL;
@@ -95,10 +95,15 @@ static long cachefiles_ondemand_fd_ioctl(struct file *filp, unsigned int ioctl,
if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags))
return -EOPNOTSUPP;
- id = arg;
- req = xa_erase(&cache->reqs, id);
- if (!req)
+ xa_lock(&cache->reqs);
+ req = xas_load(&xas);
+ if (!req || req->msg.opcode != CACHEFILES_OP_READ ||
+ req->object != object) {
+ xa_unlock(&cache->reqs);
return -EINVAL;
+ }
+ xas_store(&xas, NULL);
+ xa_unlock(&cache->reqs);
trace_cachefiles_ondemand_cread(object, id);
complete(&req->done);
@@ -126,6 +131,7 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
unsigned long id;
long size;
int ret;
+ XA_STATE(xas, &cache->reqs, 0);
if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags))
return -EOPNOTSUPP;
@@ -149,9 +155,16 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
if (ret)
return ret;
- req = xa_erase(&cache->reqs, id);
- if (!req)
+ xa_lock(&cache->reqs);
+ xas.xa_index = id;
+ req = xas_load(&xas);
+ if (!req || req->msg.opcode != CACHEFILES_OP_OPEN ||
+ !req->object->ondemand->ondemand_id) {
+ xa_unlock(&cache->reqs);
return -EINVAL;
+ }
+ xas_store(&xas, NULL);
+ xa_unlock(&cache->reqs);
/* fail OPEN request if copen format is invalid */
ret = kstrtol(psize, 0, &size);
--
2.39.2
next prev parent reply other threads:[~2024-04-24 3:48 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 3:39 [PATCH 00/12] cachefiles: some bugfixes and cleanups for ondemand requests libaokun
2024-04-24 3:39 ` [PATCH 01/12] cachefiles: remove request from xarry during flush requests libaokun
2024-04-25 3:13 ` Jia Zhu
2024-05-06 3:48 ` Jingbo Xu
2024-05-06 3:57 ` Baokun Li
2024-05-06 5:50 ` Jingbo Xu
2024-05-07 6:52 ` Baokun Li
2024-04-24 3:39 ` [PATCH 02/12] cachefiles: remove err_put_fd tag in cachefiles_ondemand_daemon_read() libaokun
2024-04-25 3:17 ` Jia Zhu
2024-05-06 3:55 ` Jingbo Xu
2024-05-06 4:02 ` Baokun Li
2024-04-24 3:39 ` [PATCH 03/12] cachefiles: fix slab-use-after-free in cachefiles_ondemand_get_fd() libaokun
2024-04-24 14:55 ` Jia Zhu
2024-04-25 1:33 ` Baokun Li
2024-04-25 3:39 ` Jia Zhu
2024-04-24 3:39 ` [PATCH 04/12] cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read() libaokun
2024-04-25 3:42 ` [External] " Jia Zhu
2024-04-24 3:39 ` [PATCH 05/12] cachefiles: add output string to cachefiles_obj_[get|put]_ondemand_fd libaokun
2024-04-24 3:39 ` libaokun [this message]
2024-05-06 2:31 ` [PATCH 06/12] cachefiles: add consistency check for copen/cread Jingbo Xu
2024-05-06 3:12 ` Baokun Li
2024-04-24 3:39 ` [PATCH 07/12] cachefiles: add spin_lock for cachefiles_ondemand_info libaokun
2024-05-06 2:55 ` Jingbo Xu
2024-05-06 3:23 ` Baokun Li
2024-04-24 3:39 ` [PATCH 08/12] cachefiles: never get a new anon fd if ondemand_id is valid libaokun
2024-05-06 3:09 ` Jingbo Xu
2024-05-07 9:32 ` Baokun Li
2024-04-24 3:39 ` [PATCH 09/12] cachefiles: defer exposing anon_fd until after copy_to_user() succeeds libaokun
2024-05-06 3:24 ` Jingbo Xu
2024-05-06 3:34 ` Baokun Li
2024-04-24 3:39 ` [PATCH 10/12] cachefiles: Set object to close if ondemand_id < 0 in copen libaokun
2024-04-25 4:56 ` Jia Zhu
2024-04-24 3:39 ` [PATCH 11/12] cachefiles: flush all requests after setting CACHEFILES_DEAD libaokun
2024-04-24 3:39 ` [PATCH 12/12] cachefiles: make on-demand read killable libaokun
2024-04-25 5:15 ` Jia Zhu
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