From owner-freebsd-bugs@freebsd.org Thu Jan 23 00:44:29 2020 Return-Path: Delivered-To: freebsd-bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id BBD782238BB for ; Thu, 23 Jan 2020 00:44:29 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 4833SY4dvpz3GNF for ; Thu, 23 Jan 2020 00:44:29 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 9D7AC2238BA; Thu, 23 Jan 2020 00:44:29 +0000 (UTC) Delivered-To: bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9C1E32238B9 for ; Thu, 23 Jan 2020 00:44:29 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4833SY3Wynz3GND for ; Thu, 23 Jan 2020 00:44:29 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 704A66438 for ; Thu, 23 Jan 2020 00:44:29 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 00N0iTOC088869 for ; Thu, 23 Jan 2020 00:44:29 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 00N0iSQa088829 for bugs@FreeBSD.org; Thu, 23 Jan 2020 00:44:28 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 243533] vt_fb.c can overwrite frame buffer bounds if stride length is not a multiple of bytes-per-pixel Date: Thu, 23 Jan 2020 00:44:15 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: thoma555-bsd@yahoo.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Jan 2020 00:44:29 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D243533 Bug ID: 243533 Summary: vt_fb.c can overwrite frame buffer bounds if stride length is not a multiple of bytes-per-pixel Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: thoma555-bsd@yahoo.com Created attachment 210977 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D210977&action= =3Dedit fix vt_fb_blank(). I'm developing a frame buffer driver for hardware using 3 bytes per pixel b= ut the hardware requires the stride to be a multiple of 256 bytes. Because the stride is not a multiple of 3 bytes, the way vt_fb_blank() is coded, it wri= tes past the end of each stride and, on the last line, writes past the end of t= he frame buffer. This is caught by a KASSERT in vt_fb_mem_wr1(). I think the loops in vt_fb_blank() could just stop at the end of the line (fb_width) instead of clearing memory all the way to the end of a stride. = The other way would be to limit the loops with fb_stride - 1, fb_stride - 2, fb_stride - 3 for the cases of 2,3,4 bytes per pixel. --=20 You are receiving this mail because: You are the assignee for the bug.=