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=1794061055; b=LQGBZM4bq7JOFq2leUYjkTJ7a/5UIBDolRdTCAbBVbPGsOUev+ZUVaTcRrzOVk7kH1Jb T6Or6wIz9yMKwdv5KLjC+J0PNYWLaN8cwrQSWkeBTDgSaQtSEY2ZEAatZUALqhMLe2HuG 5UC9ztS46X2x60K1VagGg2BITiARehgqDUn64838yjFv9X/p7Vf7lgM1JPF3UoExvuKUM AAxTY30bu1Zct0S9nDHqFRaFI0RccwOJglQP0ofKhOnOk8DCZvUgbhc6QJUa/9ASJiFLQ HhwXsHqJ3J2R6UKnJrjLMaybJr0NCrYcgPnJHrozWTDoA7K+XsarW0mh4oY9NDeddXQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061055; 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=rX4Q91v41+czhTPbt4Mw8Gjkb0bz7K3VvM1cBcKSQzY=; b=QJwmmdl4LrEXStVQrEUsFdg8iDBsF5TkbLL2voBW6TKut4wHHBhwJWjuymfe72qLRZdA Tpr6fQA56dS/6yIrNY2LPb6n2aTrbh4nQNZxdpSBzh9xCcSqI+94JqNFonVbVgddRNdjl skL0I8sy/QI4BPsIPyuvibpl7uc1qeRo2JCB4lwcw5YxV3J9O6hca5s/pF3N/w//RoZH2 6cndY6jwRirMNGsEM63y1WXWa6KjBKOjzcM/0xfl5RhqhqBkhJC7sQ0ifDVh5bsRZuM3T +EyjlvmZTLJUqCrGX3+GQAOycmTo+o98Tv1qLFCXGQg3tTNZvfTyoSa41vjIbxAaIfw== 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=lFP3p8GX; 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 CDF4B606D813; Sat, 7 Nov 2026 14:17:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=lFP3p8GX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B2701F0089F; Sat, 7 Nov 2026 14:17:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061054; bh=rX4Q91v41+czhTPbt4Mw8Gjkb0bz7K3VvM1cBcKSQzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lFP3p8GXizXZq5kjptPpOJ4MmaZYsU2nUmugC8SE7m5Q6NN4CXxwqWMluoLkZlG2F +0xHGET17ZqnRG9iBTJzTFKi343WMqjCi1PXW6+3Vt6kycJzApej/WYLsOfC23KMpP 4+aCRj5hXfmrlVXQugtaNU1LHlsILknymsVSGVLg= 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 6.12 0386/1536] fbcon: Fix KASAN slab-out-of-bounds Read in fbcon_prepare_logo Date: Sat, 7 Nov 2026 08:40:02 -0500 Message-ID: <20261107135008.455170824@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-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 5ce1aba2e7615..e582314f1ccc3 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -596,6 +596,13 @@ 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