漏洞标题
io_uring:始终从iowq进行原子放回操作
漏洞描述信息
## 漏洞概述
在Linux内核中,`io_uring`组件存在一个缺陷,即在`iowq`执行时总是切换请求到原子引用计数,这可能导致数据竞争问题。
## 影响版本
暂无具体版本号信息。
## 细节
`io_uring`总是通过设置`REQ_F_REFCOUNT`标志将请求切换到原子引用计数,以确保在任何并行执行之前切换引用计数。然而,当请求所有者更改其他标志位时,KCSAN(Kernel Concurrency Sanitizer)仍然会发出警告:
```plaintext
BUG: KCSAN: data-race in io_req_task_cancel / io_wq_free_work
...
read to 0xffff888117207448 of 8 bytes by task 3871 on cpu 0:
req_ref_put_and_test io_uring/refs.h:22 [inline]
```
由于知道该标志已被设置,解决方案是针对`iowq`跳过`REQ_F_REFCOUNT`检查。
## 影响
该问题可能导致数据竞争,进而引发潜在的安全和稳定性问题。KCSAN的警告表明代码中可能存在未预期的值计算,从而影响系统的并发执行并发性能。
CVSS信息
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
漏洞类别
使用共享资源的并发执行不恰当同步问题(竞争条件)
漏洞标题
io_uring: always do atomic put from iowq
漏洞描述信息
In the Linux kernel, the following vulnerability has been resolved:
io_uring: always do atomic put from iowq
io_uring always switches requests to atomic refcounting for iowq
execution before there is any parallilism by setting REQ_F_REFCOUNT,
and the flag is not cleared until the request completes. That should be
fine as long as the compiler doesn't make up a non existing value for
the flags, however KCSAN still complains when the request owner changes
oter flag bits:
BUG: KCSAN: data-race in io_req_task_cancel / io_wq_free_work
...
read to 0xffff888117207448 of 8 bytes by task 3871 on cpu 0:
req_ref_put_and_test io_uring/refs.h:22 [inline]
Skip REQ_F_REFCOUNT checks for iowq, we know it's set.
CVSS信息
N/A
漏洞类别
N/A