From nobody Tue Mar 3 03:20:26 2026 Received: from out-189.mta1.migadu.com (out-189.mta1.migadu.com [95.215.58.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C93DB39EF14 for ; Mon, 2 Mar 2026 20:59:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.189 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772485202; cv=none; b=HJSNtMb3kjP2Cw1eonm69MMf6wGrihP7wpm7ZjOR4SH03jmxL08iwQ2acrnJaSnasxCVQbtdiPWi6d4w6pjERfyojtYegRdUHOAETKKtlWdTswrUbPPjmPQiL8YAov4H9qjtcDyN1AqRh82/NuvQ7ZqqT5qj182LLQrPns0mz4M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772485202; c=relaxed/simple; bh=dwW89KcA/JtTK2NDUtHzWQkeHZsBnRoWA9pgOfQEpS4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=XNI918BIlyb3ab4gyvIufygJhS3jK2GfGSNXfQoVdgT+Xhd9Du7GgnPp+rIOOBhgd+W4WSvbIcl73R5WXSavVEEONzQmpZuVUUXovE5m95TcQss1NeIZOPAnSqCqB6fkBIRrXmJWZ/rpWV4slONTJtNNqjurFKLLLDXmPm/i+sY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=C+auGhWz; arc=none smtp.client-ip=95.215.58.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="C+auGhWz" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1772485197; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=PSUCx0JU19PweJ9T/g5ckfI7DhyuqktfNCfXRjrXL20=; b=C+auGhWzPod2NvvlAQUT0tBhrSd3iSIrDLM20hptSrXGEaPBD713ptlmJSnEyUdmuUWana 1rquX/qrzCuhL+abrG6tmLevlftuzAGT6yvdrcJNnJQPypGn3EP3y2jPN89y1ZyauirnQg yEXWbOtV+Diy3dSCGHHOaL68b1PxtOs= From: Thorsten Blum To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "Mike Rapoport (Microsoft)" , Andrew Morton , Changyuan Lyu , Alexander Graf , Baoquan He Cc: Thorsten Blum , stable@vger.kernel.org, Ingo Molnar , linux-kernel@vger.kernel.org Subject: [PATCH] x86/boot: Fix NULL dereference for missing hugepagesz/hugepages value Date: Mon, 2 Mar 2026 21:58:59 +0100 Message-ID: <20260302205901.39610-1-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" In parse_gb_huge_pages(), 'val' can be NULL if '=3D' is missing from the boot parameter. The code passes 'val' to memparse() and simple_strtoull(), which can dereference NULL. Reject 'hugepagesz' and 'hugepages' when no value has been provided and log a warning. Fixes: 9b912485e0e7 ("x86/boot/KASLR: Add two new functions for 1GB huge pa= ges handling") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum --- arch/x86/boot/compressed/kaslr.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/ka= slr.c index 3b0948ad449f..88ccc3b2c5aa 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -205,6 +205,11 @@ static void parse_gb_huge_pages(char *param, char *val) char *p; =20 if (!strcmp(param, "hugepagesz")) { + if (!val) { + warn("Missing value in hugepagesz=3D boot parameter\n"); + return; + } + p =3D val; if (memparse(p, &p) !=3D PUD_SIZE) { gbpage_sz =3D false; @@ -218,6 +223,11 @@ static void parse_gb_huge_pages(char *param, char *val) } =20 if (!strcmp(param, "hugepages") && gbpage_sz) { + if (!val) { + warn("Missing value in hugepages=3D boot parameter\n"); + return; + } + p =3D val; max_gb_huge_pages =3D simple_strtoull(p, &p, 0); return; --=20 Thorsten Blum GPG: 1D60 735E 8AEF 3BE4 73B6 9D84 7336 78FD 8DFE EAD4