# CVE-2021-47124: linux: In the Linux kernel, the following vulnerability has been resolved:  io_uring: fix link timeout refs  WARNING: CPU: 0...

CVE-2021-47124 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47124, released March 15, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-47124
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0024
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 15, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  io_uring: fix link timeout refs  WARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Call 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:9182  io_link_timeout_fn() should put only one reference of the linked timeout request, however in case of racing with the master request's completion first io_req_complete() puts one and then io_put_req_deferred() is called.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.14.6-1 | [DEBIAN-CVE-2021-47124](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47124.md) | Mar 15, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.14.6-1 | [DEBIAN-CVE-2021-47124](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47124.md) | Mar 15, 2024 |
| Linux | linux Debian 14 | 5.14.6-1 | [DEBIAN-CVE-2021-47124](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47124.md) | Mar 15, 2024 |

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