# CVE-2022-49407: dlm: fix plock invalid read

> A local attacker can trigger an out-of-bounds read in the Linux kernel DLM module, potentially causing a system crash or leaking sensitive memory data.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Feb 2025
- **Updated:** 15 Oct 2026
- **Also known as:** DEBIAN-CVE-2022-49407, GHSA-vgg3-rg3w-f5j6, UBUNTU-CVE-2022-49407

## What is CVE-2022-49407?

CVE-2022-49407 is a critical memory corruption vulnerability in Linux kernel, published on 26 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

dlm: fix plock invalid read

This patch fixes an invalid read showed by KASAN. A unlock will allocate a
"struct plock_op" and a followed send_op() will append it to a global
send_list data structure. In some cases a followed dev_read() moves it
to recv_list and dev_write() will cast it to "struct plock_xop" and access
fields which are only available in those structures. At this point an
invalid read happens by accessing those fields.

To fix this issue the "callback" field is moved to "struct plock_op" to
indicate that a cast to "plock_xop" is allowed and does the additional
"plock_xop" handling if set.

Example of the KASAN output which showed the invalid read:

[ 2064.296453] ==================================================================
[ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm]
[ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484
[ 2064.308168]
[ 2064.308575] CPU: 0 PID: 7484 Comm: dlm_controld Kdump: loaded Not tainted 5.14.0+ #9
[ 2064.310292] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 2064.311618] Call Trace:
[ 2064.312218]  dump_stack_lvl+0x56/0x7b
[ 2064.313150]  print_address_description.constprop.8+0x21/0x150
[ 2064.314578]  ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.315610]  ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.316595]  kasan_report.cold.14+0x7f/0x11b
[ 2064.317674]  ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.318687]  dev_write+0x52b/0x5a0 [dlm]
[ 2064.319629]  ? dev_read+0x4a0/0x4a0 [dlm]
[ 2064.320713]  ? bpf_lsm_kernfs_init_security+0x10/0x10
[ 2064.321926]  vfs_write+0x17e/0x930
[ 2064.322769]  ? __fget_light+0x1aa/0x220
[ 2064.323753]  ksys_write+0xf1/0x1c0
[ 2064.324548]  ? __ia32_sys_read+0xb0/0xb0
[ 2064.325464]  do_syscall_64+0x3a/0x80
[ 2064.326387]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2064.327606] RIP: 0033:0x7f807e4ba96f
[ 2064.328470] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 87 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 87 f8 ff 48
[ 2064.332902] RSP: 002b:00007ffd50cfe6e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 2064.334658] RAX: ffffffffffffffda RBX: 000055cc3886eb30 RCX: 00007f807e4ba96f
[ 2064.336275] RDX: 0000000000000040 RSI: 00007ffd50cfe7e0 RDI: 0000000000000010
[ 2064.337980] RBP: 00007ffd50cfe7e0 R08: 0000000000000000 R09: 0000000000000001
[ 2064.339560] R10: 000055cc3886eb30 R11: 0000000000000293 R12: 000055cc3886eb80
[ 2064.341237] R13: 000055cc3886eb00 R14: 000055cc3886f590 R15: 0000000000000001
[ 2064.342857]
[ 2064.343226] Allocated by task 12438:
[ 2064.344057]  kasan_save_stack+0x1c/0x40
[ 2064.345079]  __kasan_kmalloc+0x84/0xa0
[ 2064.345933]  kmem_cache_alloc_trace+0x13b/0x220
[ 2064.346953]  dlm_posix_unlock+0xec/0x720 [dlm]
[ 2064.348811]  do_lock_file_wait.part.32+0xca/0x1d0
[ 2064.351070]  fcntl_setlk+0x281/0xbc0
[ 2064.352879]  do_fcntl+0x5e4/0xfe0
[ 2064.354657]  __x64_sys_fcntl+0x11f/0x170
[ 2064.356550]  do_syscall_64+0x3a/0x80
[ 2064.358259]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2064.360745]
[ 2064.361511] Last potentially related work creation:
[ 2064.363957]  kasan_save_stack+0x1c/0x40
[ 2064.365811]  __kasan_record_aux_stack+0xaf/0xc0
[ 2064.368100]  call_rcu+0x11b/0xf70
[ 2064.369785]  dlm_process_incoming_buffer+0x47d/0xfd0 [dlm]
[ 2064.372404]  receive_from_sock+0x290/0x770 [dlm]
[ 2064.374607]  process_recv_sockets+0x32/0x40 [dlm]
[ 2064.377290]  process_one_work+0x9a8/0x16e0
[ 2064.379357]  worker_thread+0x87/0xbf0
[ 2064.381188]  kthread+0x3ac/0x490
[ 2064.383460]  ret_from_fork+0x22/0x30
[ 2064.385588]
[ 2064.386518] Second to last potentially related work creation:
[ 2064.389219]  kasan_save_stack+0x1c/0x40
[ 2064.391043]  __kasan_record_aux_stack+0xaf/0xc0
[ 2064.393303]  call_rcu+0x11b/0xf70
[ 2064.394885]  dlm_process_incoming_buffer+0x47d/0xfd0 [dlm]
[ 2064.397694]  receive_from_sock+0x290/0x770 
---truncated---

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2022-49407?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49407?

Apply the vendor's patch.

## Is CVE-2022-49407 being exploited?

There is no known exploitation of CVE-2022-49407 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-2022-49407 and fix it if it is affected.

What it is: CVE-2022-49407 is a critical memory corruption vulnerability in Linux kernel, published on 26 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-49407 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-2022-49407/ (Markdown: https://insights.sbomify.com/CVE-2022-49407/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49407
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49407
- OSV: https://osv.dev/vulnerability/CVE-2022-49407

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49407/
Summaries are generated and may contain mistakes; the official description above is the record.