漏洞标题
sched: 修复 sched_setaffinity 中的警告信息
漏洞描述信息
在Linux内核中,已修复了以下漏洞:
sched: 修复sched_setaffinity中的警告
提交8f9ea86fdf99b在sched_setaffinity中添加了一些逻辑,其中包括当每个任务的亲和性分配与cpuset更新竞争时会触发一个WARN。
具体来说,可能会出现一种竞争情况,即cpuset更新导致任务亲和性不再成为cpuset的子集。这是可以接受的,我们有一个备用方案,即使用cpuset掩码。然而,我们设置了一个WARN,如果cpuset掩码与请求的任务亲和性完全没有重叠,WARN会被触发。这不应被视为警告条件,创建这种条件非常简单。
通过以下设置重现了警告:
- 进程$PID在一个cpuset cgroup中
- 另一个线程反复将cpuset的CPU从1-2切换到仅1
- 另一个线程反复设置$PID的亲和性(通过taskset)为2
CVSS信息
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/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
sched: fix warning in sched_setaffinity
漏洞描述信息
In the Linux kernel, the following vulnerability has been resolved:
sched: fix warning in sched_setaffinity
Commit 8f9ea86fdf99b added some logic to sched_setaffinity that included
a WARN when a per-task affinity assignment races with a cpuset update.
Specifically, we can have a race where a cpuset update results in the
task affinity no longer being a subset of the cpuset. That's fine; we
have a fallback to instead use the cpuset mask. However, we have a WARN
set up that will trigger if the cpuset mask has no overlap at all with
the requested task affinity. This shouldn't be a warning condition; its
trivial to create this condition.
Reproduced the warning by the following setup:
- $PID inside a cpuset cgroup
- another thread repeatedly switching the cpuset cpus from 1-2 to just 1
- another thread repeatedly setting the $PID affinity (via taskset) to 2
CVSS信息
N/A
漏洞类别
N/A
漏洞标题
Linux kernel 安全漏洞
漏洞描述信息
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞,该漏洞源于调度器的sched_setaffinity函数在任务亲和性与cpuset更新竞争时,可能导致警告。
CVSS信息
N/A
漏洞类别
其他