Bug 2492380 (CVE-2026-53046)

Summary:	CVE-2026-53046 kernel: ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's ksmbd component. This vulnerability, a use-after-free, occurs when the ksmbd component incorrectly handles asynchronous (async) cryptographic operations, specifically with hardware crypto engines like the Qualcomm Crypto Engine (QCE). When the QCE returns an in-progress status, ksmbd prematurely frees memory while hardware operations are still active. This can lead to a NULL pointer crash, resulting in a Denial of Service (DoS) for the system.	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-06-24 18:08:55 UTC

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).

Comment 1 Keith Grant 2026-06-25 19:53:03 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062458-CVE-2026-53046-39ee@gregkh/T