CVEs-PoC/2021/CVE-2021-47569.md

### [CVE-2021-47569](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-47569)
![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=5.15%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=89b263f6d56e683ddcf7643140271ef6e36c72b9%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=blue)

### Description

In the Linux kernel, the following vulnerability has been resolved:io_uring: fail cancellation for EXITING tasksWARNING: CPU: 1 PID: 20 at fs/io_uring.c:6269 io_try_cancel_userdata+0x3c5/0x640 fs/io_uring.c:6269CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 5.16.0-rc1-syzkaller #0Workqueue: events io_fallback_req_funcRIP: 0010:io_try_cancel_userdata+0x3c5/0x640 fs/io_uring.c:6269Call Trace: <TASK> io_req_task_link_timeout+0x6b/0x1e0 fs/io_uring.c:6886 io_fallback_req_func+0xf9/0x1ae fs/io_uring.c:1334 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK>We need original task's context to do cancellations, so if it's dyingand the callback is executed in a fallback mode, fail the cancellationattempt.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/fkie-cad/nvd-json-data-feeds