From nobody Mon Feb 9 12:15:35 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 E47B02E2DDC for ; Thu, 9 Oct 2025 12:30:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760013045; cv=none; b=lbJlctdqX8fpeoDXbF+yTOxLrYUbcicibprQ07ODBqVlMh94yvFF3JLQH5P2XZLWKR23MUj0hSFgNv5RfHsxwDZ1Ab5QpvDP/0VairmofsErm558bkmYVYwaExb8azg4bV5ATZmw2001mJxqsAwQTq39s6yXhvBC7ca9q6YRyWI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760013045; c=relaxed/simple; bh=x/xBOWDUp28sfsBV56l3ubXJEEtbz5ccQGgEvAY4eak=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gJigqLBFagYlNFQXSmAT2nnqcNM6N4L4z/IOOITJOVIIxpZYy+GuQHervVvkiC4zvQ2jwtevf4msMBKoTBvuiSSQi/lthfz0g8leLsbFm3BU1Iw4MdtqD/KVKASGmgGGzAAFhrKXawCgFLozTpGXBmTQA0Cj5RdXhzMAld1+0so= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LB5eQYYx; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LB5eQYYx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1760013042; 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: in-reply-to:in-reply-to:references:references; bh=Cn5dPHJR4fGLCx+LL6EWkDNRU/ebLqiGoCggED75pSc=; b=LB5eQYYxBd7yG1Q2oxK2Ldxr0SmVHRyUMafz8xoXjNczNVl9uouSWIFrn1zk5z6LIQrvLx G+8fefhE9lDJYWm7H0JjQq7Z4ln/8Rc1MqY5BE4se0w+wDr1vzqKXTJFXHd3kW4HZJ3lkq hWnr849hCcDgIF9on7/bMxFRPnfq9Sc= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-15-uVIGwZ_LMbGTAMeUefY4JQ-1; Thu, 09 Oct 2025 08:30:35 -0400 X-MC-Unique: uVIGwZ_LMbGTAMeUefY4JQ-1 X-Mimecast-MFC-AGG-ID: uVIGwZ_LMbGTAMeUefY4JQ_1760013034 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 288F4195608E; Thu, 9 Oct 2025 12:30:34 +0000 (UTC) Received: from hydra.redhat.com (unknown [10.45.225.212]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id BEF51180035E; Thu, 9 Oct 2025 12:30:30 +0000 (UTC) From: Jocelyn Falempe To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jocelyn Falempe , Javier Martinez Canillas , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org Subject: [PATCH 5/6] drm/panic: Fix divide by 0 if the screen width < font width Date: Thu, 9 Oct 2025 14:24:52 +0200 Message-ID: <20251009122955.562888-6-jfalempe@redhat.com> In-Reply-To: <20251009122955.562888-1-jfalempe@redhat.com> References: <20251009122955.562888-1-jfalempe@redhat.com> 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-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" In the unlikely case that the screen is tiny, and smaller than the font width, it leads to a divide by 0: draw_line_with_wrap() chars_per_row =3D sb->width / font->width =3D 0 line_wrap.len =3D line->len % chars_per_row; This will trigger a divide by 0 Signed-off-by: Jocelyn Falempe Reviewed-by: Javier Martinez Canillas --- drivers/gpu/drm/drm_panic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c index 69be9d835ccf..bc5158683b2b 100644 --- a/drivers/gpu/drm/drm_panic.c +++ b/drivers/gpu/drm/drm_panic.c @@ -523,7 +523,7 @@ static void draw_panic_static_kmsg(struct drm_scanout_b= uffer *sb) struct drm_panic_line line; int yoffset; =20 - if (!font) + if (!font || font->width > sb->width) return; =20 yoffset =3D sb->height - font->height - (sb->height % font->height) / 2; --=20 2.51.0