[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2 3/3] libfdt: fix UBSAN null pointer in fdt_property()
- To: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: "Orzel, Michal" <michal.orzel@xxxxxxx>
- Date: Tue, 26 May 2026 08:22:44 +0200
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=gmail.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0)
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=UkCzIeLvWAh14bJC5YgrJi7rKh2KALBGsS7powMCtXQ=; b=Cs9ffql22BTLbj8GBVCfsJalxYyd5+CJ/0oxc8WEmfp8z82o+CUb/V0nA8W8hufys/snaE4NrgnPPMyVzSLQyjs65oWU+n2h/lcmLb5xR4/PZ5rtPUKWpM3ehkWbdy2VQ2aXROA7cuS4/dfWxckslyFMmSrcRh8DURhvjH0ev9DbNUZljaG8cXRCfbESRZIbItG6P1Sns9WAeW8em3CVGeipl66BRd615qWXIRIXWAQrXzdIZQtYTD+Y/c1zRD02PMzU8MylkU3G7rJuupNSaSKrtv/hQOTrN8nIPuVA1zmX6bVeAwD4cGVZ/MUDFD5may1NcHsDQgVc3YT9WFYChg==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ehJHvpXzD7WIvvFuJcG0IYZ8Z1AYGsEH6QqWnKMWzZMsvFnSq07ETFf7XQbpQccI/ppSQgLTivaqlb7kKasI9HL+RN0xjzl4txyCnRkcuLoPQctwd2GBgMKIJoklNfKIQczoiBYzC3oAJa+NjD4+6F/Mcb5d2BCfFU+9anJr7K/o+VGUoMFDpI7YIS4U2N6Th7ONg6puZ8hCmOQNvbgwqQlbkDWl9D6ruVghx3vM+bJumW7lKqdR1Wzb0UMVtyGtIdx6USJBlzaiiOjbIdh2jwPWM0voiDrzlxqnU1ml8EK1YjEyfhjDCddEwHLgsKVxbvifMLDKHqnzLAJt1Hq3Ng==
- Authentication-results: eu.smtp.expurgate.cloud; dkim=pass header.s=selector1 header.d=amd.com header.i="@amd.com" header.h="From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck"
- Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Bertrand Marquis <bertrand.marquis@xxxxxxx>, David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>, Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>
- Delivery-date: Tue, 26 May 2026 06:23:20 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 25-May-26 15:20, Oleksii Kurochko wrote:
> fdt_property() unconditionally calls memcpy(ptr, val, len) even when
> len is zero and val is NULL. This is a legitimate calling convention
> for adding empty FDT properties such as "interrupt-controller", which
> carry no payload.
>
> However, compilers that treat memcpy as nonnull on its pointer arguments
> will fire UBSAN before observing that len is zero.
>
> Guard the memcpy() with a check on len so it is skipped entirely when
> there is no payload to copy, bringing the code in line with the
> nonnull contract.
>
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> Signed-off-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> Origin: git://git.kernel.org/pub/scm/utils/dtc/dtc.git f57e7df35df4
>
> Fixes: f0ea06558068 ("libfdt: add version 1.3.0")
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> Reviewed-by: Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
~Michal
|
