# CVE-2026-80652: crypto: ccp - Treat zero-length cert chain as query for blob lengths

> A local attacker can trigger a kernel crash in the CCP driver by passing a zero-length certificate chain buffer during PDH export.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** BELL-CVE-2026-80652, DEBIAN-CVE-2026-80652, GHSA-fx6v-9wmr-6fvm, UBUNTU-CVE-2026-80652

## What is CVE-2026-80652?

CVE-2026-80652 is a vulnerability in Linux, published on 28 Aug 2026. 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:

crypto: ccp - Treat zero-length cert chain as query for blob lengths

When handling a PDH export, treat a zero-length userspace cert chain buffer
as a request to query the length of the relevant blobs.  Failure to account
for the zero-length buffer trips a BUG_ON() when running with
CONFIG_DEBUG_VIRTUAL=y due to trying to get the physical address of the
ZERO_SIZE_PTR (returned by kzalloc() on the bogus allocation).

   kernel BUG at arch/x86/mm/physaddr.c:28 !
  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
  CPU: 30 UID: 0 PID: 28580 Comm: syz.2.18 Kdump: loaded
  Tainted: G        W           6.18.16-smp-DEV #1 NONE
  Tainted: [W]=WARN
  Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.62.0-0 11/19/2025
   RIP: 0010:__phys_addr+0x16a/0x180 arch/x86/mm/physaddr.c:28
  RSP: 0018:ffffc9008329fc80 EFLAGS: 00010293
  RAX: ffffffff8179110a RBX: 0000778000000010 RCX: ffff8884e6992600
  RDX: 0000000000000000 RSI: 0000000080000010 RDI: 0000778000000010
  RBP: ffffc9008329fdf0 R08: 0000000000000dc0 R09: 00000000ffffffff
  R10: dffffc0000000000 R11: fffffbfff126d297 R12: dffffc0000000000
  R13: 1ffff92010653fc8 R14: 0000000080000010 R15: dffffc0000000000
  FS:  0000555556bec9c0(0000) GS:ffff88aa4ce1c000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd3159e7000 CR3: 00000004fbc44000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
    [<ffffffff853d3869>] sev_ioctl_do_pdh_export+0x559/0x7a0 drivers/crypto/ccp/sev-dev.c:2308
    [<ffffffff853d1fdd>] sev_ioctl+0x2cd/0x480 drivers/crypto/ccp/sev-dev.c:2556
    [<ffffffff82549ebc>] vfs_ioctl fs/ioctl.c:52 [inline]
    [<ffffffff82549ebc>] __do_sys_ioctl fs/ioctl.c:598 [inline]
    [<ffffffff82549ebc>] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584
    [<ffffffff8630115f>] do_syscall_x64 arch/x86/entry/syscall_64.c:64 [inline]
    [<ffffffff8630115f>] do_syscall_64+0x9f/0xf40 arch/x86/entry/syscall_64.c:98
   [<ffffffff81000136>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7fd3158eac39
   </TASK>

Thankfully, the bug is benign outside of CONFIG_DEBUG_VIRTUAL=y as getting
the physical address is just arithmetic, and the PSP errors out before
trying to write to the garbage address (which it must, otherwise querying
the blob lengths would clobber memory at pfn=0).

## Which versions are affected by CVE-2026-80652?


## How do I fix CVE-2026-80652?

Apply the vendor's patch.

## Is CVE-2026-80652 being exploited?

There is no known exploitation of CVE-2026-80652 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80652 and fix it if it is affected.

What it is: CVE-2026-80652 is a vulnerability in Linux, published on 28 Aug 2026. 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-2026-80652 in the wild and no public exploit code.

Affected product: Linux. 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-2026-80652/ (Markdown: https://insights.sbomify.com/CVE-2026-80652/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80652
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80652
- OSV: https://osv.dev/vulnerability/CVE-2026-80652

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80652/
Summaries are generated and may contain mistakes; the official description above is the record.