CVEs-PoC/2021/CVE-2021-47124.md

### [CVE-2021-47124](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-47124)
![](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=1c20e9040f49687ba2ccc2ffd4411351a6c2ebff%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=5.12%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=567c81912cec641db75ac6cb64c63f8367c97d19%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=9ae1f8dd372e0e4c020b345cf9e09f519265e981%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: fix link timeout refsWARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] io_put_req fs/io_uring.c:2140 [inline] io_queue_linked_timeout fs/io_uring.c:6300 [inline] __io_queue_sqe+0xbef/0xec0 fs/io_uring.c:6354 io_submit_sqe fs/io_uring.c:6534 [inline] io_submit_sqes+0x2bbd/0x7c50 fs/io_uring.c:6660 __do_sys_io_uring_enter fs/io_uring.c:9240 [inline] __se_sys_io_uring_enter+0x256/0x1d60 fs/io_uring.c:9182io_link_timeout_fn() should put only one reference of the linked timeoutrequest, however in case of racing with the master request's completionfirst io_req_complete() puts one and then io_put_req_deferred() iscalled.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/NaInSec/CVE-LIST