From nobody Sat Dec 21 15:39:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of seabios.org designates 78.46.105.101 as permitted sender) client-ip=78.46.105.101; envelope-from=seabios-bounces@seabios.org; helo=coreboot.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of seabios.org designates 78.46.105.101 as permitted sender) smtp.mailfrom=seabios-bounces@seabios.org Return-Path: Received: from coreboot.org (coreboot.org [78.46.105.101]) by mx.zohomail.com with SMTPS id 1709802851584358.5981959483154; Thu, 7 Mar 2024 01:14:11 -0800 (PST) Received: from authenticated-user (PRIMARY_HOSTNAME [PUBLIC_IP]) by coreboot.org (Postfix) with ESMTPA id 056EC244BD; Thu, 7 Mar 2024 09:14:04 +0000 (UTC) Received: from authenticated-user (PRIMARY_HOSTNAME [PUBLIC_IP]) by coreboot.org (Postfix) with ESMTP id B068824363 for ; Thu, 7 Mar 2024 09:13:44 +0000 (UTC) Received: from authenticated-user (PRIMARY_HOSTNAME [PUBLIC_IP]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) (Authenticated sender: daniel@drv.nu) by oak.drv.nu (Postfix) with ESMTPSA id A5F65103045; Thu, 7 Mar 2024 01:13:42 -0800 (PST) From: Daniel Verkamp To: seabios@seabios.org Date: Thu, 7 Mar 2024 01:08:27 -0800 Message-ID: <20240307091317.2655196-1-daniel@drv.nu> MIME-Version: 1.0 X-Spam-Level: ** Message-ID-Hash: DZDYLAFOYQUWVAMZFIM254QSG3QA4ZWU X-Message-ID-Hash: DZDYLAFOYQUWVAMZFIM254QSG3QA4ZWU X-MailFrom: daniel@drv.nu X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-seabios.seabios.org-0; header-match-seabios.seabios.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [SeaBIOS] [PATCH v2] vbe: Add VBE 2.0+ OemData field to struct vbe_info List-Id: SeaBIOS mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable Authentication-Results: coreboot.org; auth=pass smtp.auth=mailman@coreboot.org smtp.mailfrom=seabios-bounces@seabios.org X-Spamd-Bar: / X-ZM-MESSAGEID: 1709802853516100001 Content-Type: text/plain; charset="utf-8" Per the VBE 2.0 specification, the VBE controller information is 512 bytes long when the "VBE2" signature is provided, instead of the original 256 bytes. src/bootsplash.c uses the original pre-VBE-2.0 256-byte structure while also filling in the "VBE2" signature, so a video BIOS that makes use of the VBE2 OemData area could write past the end of the allocated region. The original bootsplash code did not have this bug; it was introduced when the bootsplash VBE structures were merged with the VGA ROM struct definitions. Fixes: 69e941c159ed ("Merge bootsplash and VGA ROM vbe structure definition= s") Signed-off-by: Daniel Verkamp --- v2 fixes the inverse bug introduced by the original patch - the vgabios would memset too much data if the caller did not request VBE2 data. src/std/vbe.h | 2 ++ vgasrc/vbe.c | 4 +++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/src/std/vbe.h b/src/std/vbe.h index 94b4ad86..fe96f5ec 100644 --- a/src/std/vbe.h +++ b/src/std/vbe.h @@ -18,6 +18,8 @@ struct vbe_info { struct segoff_s oem_product_string; struct segoff_s oem_revision_string; u8 reserved[222]; + /* VBE 2.0 */ + u8 oem_data[256]; } PACKED; =20 struct vbe_mode_info { diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c index 66afb011..91abc9ab 100644 --- a/vgasrc/vbe.c +++ b/vgasrc/vbe.c @@ -32,16 +32,18 @@ vbe_104f00(struct bregs *regs) { u16 seg =3D regs->es; struct vbe_info *info =3D (void*)(regs->di+0); + size_t info_size =3D offsetof(struct vbe_info, oem_data); =20 if (GET_FARVAR(seg, info->signature) =3D=3D VBE2_SIGNATURE) { dprintf(4, "Get VBE Controller: VBE2 Signature found\n"); + info_size =3D sizeof(*info); } else if (GET_FARVAR(seg, info->signature) =3D=3D VESA_SIGNATURE) { dprintf(4, "Get VBE Controller: VESA Signature found\n"); } else { dprintf(4, "Get VBE Controller: Invalid Signature\n"); } =20 - memset_far(seg, info, 0, sizeof(*info)); + memset_far(seg, info, 0, info_size); =20 SET_FARVAR(seg, info->signature, VESA_SIGNATURE); =20 --=20 2.43.0 _______________________________________________ SeaBIOS mailing list -- seabios@seabios.org To unsubscribe send an email to seabios-leave@seabios.org