From: Holger Dengler <dengler@linux.ibm.com>
To: Harald Freudenberger <freude@linux.ibm.com>
Cc: fcallies@linux.ibm.com, linux-s390@vger.kernel.org,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>
Subject: Re: [PATCH v3 2/2] s390/zcrypt: Fix out-of-bounds ptr advance in cca_query_crypto_facility()
Date: Thu, 8 Oct 2026 16:48:50 +0200 [thread overview]
Message-ID: <7c624474-ffd4-4899-90c8-3d3cbf9997ee@linux.ibm.com> (raw)
In-Reply-To: <20261006154603.9699-3-freude@linux.ibm.com>
On 10/6/26 17:46, Harald Freudenberger wrote:
> The FQ reply parser code blindly advanced the walk pointer by a length
> value read directly from the hardware reply payload without checking
> that the advance stayed within the allocated reply buffer. A corrupt
> or malicious device response could push ptr beyond the cprbmem region,
> causing an out-of-bounds dereference or kernel memory exposure via the
> subsequent memcpy().
>
> Fix this by tracking the remaining reply buffer space in a variable
> and validating each device-supplied length field against it before
> advancing or dereferencing the pointer.
>
> Fixes: 2004b57cde6b ("s390/zcrypt: code cleanup")
> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
> Cc: stable@vger.kernel.org
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
--
Mit freundlichen Grüßen / Kind regards
Holger Dengler
next prev parent reply other threads:[~2026-10-08 14:48 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-06 15:46 [PATCH v3 0/2] Fix minor LLM findings in zcrypt dd Harald Freudenberger
2026-10-06 15:46 ` [PATCH v3 1/2] s390/zcrypt: Guard domain index uses against speculative bypass Harald Freudenberger
2026-10-06 15:55 ` sashiko-bot
2026-10-08 14:08 ` Holger Dengler
2026-10-06 15:46 ` [PATCH v3 2/2] s390/zcrypt: Fix out-of-bounds ptr advance in cca_query_crypto_facility() Harald Freudenberger
2026-10-06 15:54 ` sashiko-bot
2026-10-08 14:48 ` Holger Dengler [this message]
2026-10-08 18:02 ` [PATCH v3 0/2] Fix minor LLM findings in zcrypt dd Heiko Carstens
2026-10-08 18:05 ` Heiko Carstens
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