dbcve.org
Linux KernelOperating system · Linux

CVE-2022-50516

MEDIUM · 5.5 CVSS v3.1 Published 2025-10-07
Fix available
A fix is available. Upgrade to 5.15.76 / 5.19.17 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: fs: dlm: fix invalid derefence of sb_lvbptr I experience issues when putting a lkbsb on the stack and have sb_lvbptr field to a dangled pointer while not using DLM_LKF_VALBLK. It will crash with the following kernel message, the dangled pointer is here 0xdeadbeef as example: [ 102.749317] BUG: unable to handle page fault for address: 00000000deadbeef [ 102.749320] #PF: supervisor read access in kernel mode [ 102.749323] #PF: error_code(0x0000) - not-present page [ 102.749325] PGD 0 P4D 0 [ 102.749332] Oops: 0000 [#1] PREEMPT SMP PTI [ 102.749336] CPU: 0 PID: 1567 Comm: lock_torture_wr Tainted: G W 5.19.0-rc3+ #1565 [ 102.749343] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-2.module+el8.7.0+15506+033991b0 04/01/2014 [ 102.749344] RIP: 0010:memcpy_erms+0x6/0x10 [ 102.749353] Code: cc cc cc cc eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe [ 102.749355] RSP: 0018:ffff97a58145fd08 EFLAGS: 00010202 [ 102.749358] RAX: ffff901778b77070 RBX: 0000000000000000 RCX: 0000000000000040 [ 102.749360] RDX: 0000000000000040 RSI: 00000000deadbeef RDI: ffff901778b77070 [ 102.749362] RBP: ffff97a58145fd10 R08: ffff901760b67a70 R09: 0000000000000001 [ 102.749364] R10: ffff9017008e2cb8 R11: 0000000000000001 R12: ffff901760b67a70 [ 102.749366] R13: ffff901760b78f00 R14: 0000000000000003 R15: 0000000000000001 [ 102.749368] FS: 0000000000000000(0000) GS:ffff901876e00000(0000) knlGS:0000000000000000 [ 102.749372] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 102.749374] CR2: 00000000deadbeef CR3: 000000017c49a004 CR4: 0000000000770ef0 [ 102.749376] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 102.749378] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 102.749379] PKRU: 55555554 [ 102.749381] Call Trace: [ 102.749382] <TASK> [ 102.749383] ? send_args+0xb2/0xd0 [ 102.749389] send_common+0xb7/0xd0 [ 102.749395] _unlock_lock+0x2c/0x90 [ 102.749400] unlock_lock.isra.56+0x62/0xa0 [ 102.749405] dlm_unlock+0x21e/0x330 [ 102.749411] ? lock_torture_stats+0x80/0x80 [dlm_locktorture] [ 102.749416] torture_unlock+0x5a/0x90 [dlm_locktorture] [ 102.749419] ? preempt_count_sub+0xba/0x100 [ 102.749427] lock_torture_writer+0xbd/0x150 [dlm_locktorture] [ 102.786186] kthread+0x10a/0x130 [ 102.786581] ? kthread_complete_and_exit+0x20/0x20 [ 102.787156] ret_from_fork+0x22/0x30 [ 102.787588] </TASK> [ 102.787855] Modules linked in: dlm_locktorture torture rpcsec_gss_krb5 intel_rapl_msr intel_rapl_common kvm_intel iTCO_wdt iTCO_vendor_support kvm vmw_vsock_virtio_transport qxl irqbypass vmw_vsock_virtio_transport_common drm_ttm_helper crc32_pclmul joydev crc32c_intel ttm vsock virtio_scsi virtio_balloon snd_pcm drm_kms_helper virtio_console snd_timer snd drm soundcore syscopyarea i2c_i801 sysfillrect sysimgblt i2c_smbus pcspkr fb_sys_fops lpc_ich serio_raw [ 102.792536] CR2: 00000000deadbeef [ 102.792930] ---[ end trace 0000000000000000 ]--- This patch fixes the issue by checking also on DLM_LKF_VALBLK on exflags is set when copying the lvbptr array instead of if it's just null which fixes for me the issue. I think this patch can fix other dlm users as well, depending how they handle the init, freeing memory handling of sb_lvbptr and don't set DLM_LKF_VALBLK for some dlm_lock() calls. It might a there could be a hidden issue all the time. However with checking on DLM_LKF_VALBLK the user always need to provide a sb_lvbptr non-null value. There might be more intelligent handling between per ls lvblen, DLM_LKF_VALBLK and non-null to report the user the way how DLM API is used is wrong but can be added for later, this will only fix the current behaviour.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-476

The code follows a pointer that is null, crashing the process. An attacker who can reliably trigger it turns the crash into a denial of service. The fix is checking for null before use and handling the failure path gracefully.

General guidance for the null pointer dereference class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 2.6.19, < 5.15.76>= 5.16, < 5.19.17>= 6.0, < 6.0.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.15.76 / 5.19.17 / 6.0.3 or later
Fixed in 5.15.765.19.176.0.3
Vendor patch git.kernel.org →
Recommended fix High confidence

5.15.76, 5.19.17, or 6.0.3 (or any subsequent stable release)

  1. Upgrade the Linux kernel to version 5.15.76 or later for the 5.15.x stable branch
  2. Alternatively, upgrade to version 5.19.17 or later for the 5.19.x stable branch
  3. Alternatively, upgrade to version 6.0.3 or later for the 6.0.x stable branch
  4. After upgrading, reboot the system to load the fixed kernel
Caveat Kernel upgrades may require rebuilding out-of-tree modules; verify compatibility of kernel modules with the new version

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,850. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-50516 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-50516 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data