# CVE-2022-48954: s390/qeth: fix use-after-free in hsci

> A use-after-free vulnerability in the s390/qeth kernel driver allows attackers to cause a denial of service or potentially execute code.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Oct 2024
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-48954, GHSA-pvfv-p8r5-hrcw, UBUNTU-CVE-2022-48954

## What is CVE-2022-48954?

CVE-2022-48954 is a high-severity use after free vulnerability in Linux kernel, published on 21 Oct 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

s390/qeth: fix use-after-free in hsci

KASAN found that addr was dereferenced after br2dev_event_work was freed.

==================================================================
BUG: KASAN: use-after-free in qeth_l2_br2dev_worker+0x5ba/0x6b0
Read of size 1 at addr 00000000fdcea440 by task kworker/u760:4/540
CPU: 17 PID: 540 Comm: kworker/u760:4 Tainted: G            E      6.1.0-20221128.rc7.git1.5aa3bed4ce83.300.fc36.s390x+kasan #1
Hardware name: IBM 8561 T01 703 (LPAR)
Workqueue: 0.0.8000_event qeth_l2_br2dev_worker
Call Trace:
 [<000000016944d4ce>] dump_stack_lvl+0xc6/0xf8
 [<000000016942cd9c>] print_address_description.constprop.0+0x34/0x2a0
 [<000000016942d118>] print_report+0x110/0x1f8
 [<0000000167a7bd04>] kasan_report+0xfc/0x128
 [<000000016938d79a>] qeth_l2_br2dev_worker+0x5ba/0x6b0
 [<00000001673edd1e>] process_one_work+0x76e/0x1128
 [<00000001673ee85c>] worker_thread+0x184/0x1098
 [<000000016740718a>] kthread+0x26a/0x310
 [<00000001672c606a>] __ret_from_fork+0x8a/0xe8
 [<00000001694711da>] ret_from_fork+0xa/0x40
Allocated by task 108338:
 kasan_save_stack+0x40/0x68
 kasan_set_track+0x36/0x48
 __kasan_kmalloc+0xa0/0xc0
 qeth_l2_switchdev_event+0x25a/0x738
 atomic_notifier_call_chain+0x9c/0xf8
 br_switchdev_fdb_notify+0xf4/0x110
 fdb_notify+0x122/0x180
 fdb_add_entry.constprop.0.isra.0+0x312/0x558
 br_fdb_add+0x59e/0x858
 rtnl_fdb_add+0x58a/0x928
 rtnetlink_rcv_msg+0x5f8/0x8d8
 netlink_rcv_skb+0x1f2/0x408
 netlink_unicast+0x570/0x790
 netlink_sendmsg+0x752/0xbe0
 sock_sendmsg+0xca/0x110
 ____sys_sendmsg+0x510/0x6a8
 ___sys_sendmsg+0x12a/0x180
 __sys_sendmsg+0xe6/0x168
 __do_sys_socketcall+0x3c8/0x468
 do_syscall+0x22c/0x328
 __do_syscall+0x94/0xf0
 system_call+0x82/0xb0
Freed by task 540:
 kasan_save_stack+0x40/0x68
 kasan_set_track+0x36/0x48
 kasan_save_free_info+0x4c/0x68
 ____kasan_slab_free+0x14e/0x1a8
 __kasan_slab_free+0x24/0x30
 __kmem_cache_free+0x168/0x338
 qeth_l2_br2dev_worker+0x154/0x6b0
 process_one_work+0x76e/0x1128
 worker_thread+0x184/0x1098
 kthread+0x26a/0x310
 __ret_from_fork+0x8a/0xe8
 ret_from_fork+0xa/0x40
Last potentially related work creation:
 kasan_save_stack+0x40/0x68
 __kasan_record_aux_stack+0xbe/0xd0
 insert_work+0x56/0x2e8
 __queue_work+0x4ce/0xd10
 queue_work_on+0xf4/0x100
 qeth_l2_switchdev_event+0x520/0x738
 atomic_notifier_call_chain+0x9c/0xf8
 br_switchdev_fdb_notify+0xf4/0x110
 fdb_notify+0x122/0x180
 fdb_add_entry.constprop.0.isra.0+0x312/0x558
 br_fdb_add+0x59e/0x858
 rtnl_fdb_add+0x58a/0x928
 rtnetlink_rcv_msg+0x5f8/0x8d8
 netlink_rcv_skb+0x1f2/0x408
 netlink_unicast+0x570/0x790
 netlink_sendmsg+0x752/0xbe0
 sock_sendmsg+0xca/0x110
 ____sys_sendmsg+0x510/0x6a8
 ___sys_sendmsg+0x12a/0x180
 __sys_sendmsg+0xe6/0x168
 __do_sys_socketcall+0x3c8/0x468
 do_syscall+0x22c/0x328
 __do_syscall+0x94/0xf0
 system_call+0x82/0xb0
Second to last potentially related work creation:
 kasan_save_stack+0x40/0x68
 __kasan_record_aux_stack+0xbe/0xd0
 kvfree_call_rcu+0xb2/0x760
 kernfs_unlink_open_file+0x348/0x430
 kernfs_fop_release+0xc2/0x320
 __fput+0x1ae/0x768
 task_work_run+0x1bc/0x298
 exit_to_user_mode_prepare+0x1a0/0x1a8
 __do_syscall+0x94/0xf0
 system_call+0x82/0xb0
The buggy address belongs to the object at 00000000fdcea400
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 64 bytes inside of
 96-byte region [00000000fdcea400, 00000000fdcea460)
The buggy address belongs to the physical page:
page:000000005a9c26e8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xfdcea
flags: 0x3ffff00000000200(slab|node=0|zone=1|lastcpupid=0x1ffff)
raw: 3ffff00000000200 0000000000000000 0000000100000122 000000008008cc00
raw: 0000000000000000 0020004100000000 ffffffff00000001 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 00000000fdcea300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 00000000fdcea380: fb fb fb fb fb fb f
---truncated---

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2022-48954?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-48954?

Apply the vendor's patch.

## Is CVE-2022-48954 being exploited?

There is no known exploitation of CVE-2022-48954 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-48954 and fix it if it is affected.

What it is: CVE-2022-48954 is a high-severity use after free vulnerability in Linux kernel, published on 21 Oct 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-48954 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-48954/ (Markdown: https://insights.sbomify.com/CVE-2022-48954/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-48954
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-48954
- OSV: https://osv.dev/vulnerability/CVE-2022-48954

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-48954/
Summaries are generated and may contain mistakes; the official description above is the record.