From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831015; b=AiBDcinlGANPgkpV7ocl9wQsC6ahdVv8xyrywcRLdu3xtMojLU9k1kZHnMt2Az0qxuGg wh1O7yyelPbcpwBUUCpyV86Ne4RRYP6j6HGCGZaHse6hu0b48Cp+M8bYEJiMVTYOE1KXP sd3eKNQpV2jx1HiXOgPOjxHv7B0NMb9W7LhhpQEC73aTCcVVmJLX911SxXMEjskRd6O/Q j7IEp+U4Ht5Hztj3I5Xt/54qetDXm/t3/FBjcFQg8qJP+pW2PVR1FaXrtxHBCbE23wye0 spZM1krMAiIa8VsU/IbTVQQVfWYn4V5H+bcSo/+PDkzSEVrFUkRTRnwUtXKnjh01VjA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831015; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=stmRyUunT3K0FSL09sh0Jh5SA2K869AEY2BmGJW2LgA=; b=HWBs78ZtHiKcNiwRzHjWpDkzW/qM+yVDdVzeccHS61lvMxlQNNExr73jqNOrY4JW5BL0 cqDto5G9onALkutVUpUUYe7rpCdWzVDP7SIrN12P85KtUFQxiOyERtgfDVyHiF1xczmVb GDOXeCGx1jihwlN6cXHL8CgBfNylaXOYSUn4qZXdZUxG/HbMk1KMmv5S94v2HRhNL2OvS Z+pZwW/Pi2cKCEOlZsDdon2d86XLOTPwDnPYIPHJAhkcOfjHJfIMv9MKHe5UEr9ppAwiO Q/06yXmdEQannHkslOrQTz1yuK/VTVqQaXZwPUnlOaZO6vsmD4eqGA0R9wHZBPA/J3Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="TplYjT/E"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E91B46070327; Wed, 4 Nov 2026 22:23:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TplYjT/E Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83B9F1F000C1; Wed, 4 Nov 2026 22:23:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831014; bh=stmRyUunT3K0FSL09sh0Jh5SA2K869AEY2BmGJW2LgA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TplYjT/E1obNKd2A4R5HUpItAK38dOH8SF6FaaZpfq+loAaLEkJo0zSFcdrVz8Bot pdOSH7MSzpxsQsKHkP22RRec1N+0/6UrQhMfko4eeF+ksaFdJZWeeuP9J9OCi/1Fyy CIWykiYX9/Xctl1DeLYqwzrUbbVfd3Ke915qlwhQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+0c815b25cdb3678e7083@syzkaller.appspotmail.com, Helge Deller , Sasha Levin Subject: [PATCH 6.18 0457/1005] fbcon: Fix KASAN slab-out-of-bounds Read in fbcon_prepare_logo Date: Wed, 4 Nov 2026 16:03:10 -0500 Message-ID: <20261104211056.840049845@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Helge Deller [ Upstream commit 94e6a058b16820e02f25e1221a4c4e713ba23550 ] Ensure the logo will not exceed the screen size, which then should fix a reported KASAN: slab-out-of-bounds Read in fbcon_prepare_logo. Reported-by: syzbot+0c815b25cdb3678e7083@syzkaller.appspotmail.com Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/core/fbcon.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 532522c2aed05..903823c9ce567 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -600,6 +600,13 @@ static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info, erase &= ~0x400; logo_height = fb_prepare_logo(info, par->rotate); logo_lines = DIV_ROUND_UP(logo_height, vc->vc_font.height); + logo_lines = min(logo_lines, rows); + logo_lines = min(logo_lines, new_rows - 1); + if (logo_lines <= 0) { + logo_lines = 0; + logo_shown = FBCON_LOGO_DONTSHOW; + return; + } q = (unsigned short *) (vc->vc_origin + vc->vc_size_row * rows); step = logo_lines * cols; -- 2.53.0