From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2EA6B46C84F; Thu, 20 Aug 2026 16:41:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787244106; cv=none; b=i7GuufvdVVJW0zXT4E99n9gkZEsFFLDgLb9MOiJYjg0jngGwv1VUHuqWMz1+sCifWIbO4Ij531Cr1tuR/zBJI4nCw02JgSpAP/KJY0ZSklGHgH8C/zapBELoVOc7YuXER5LphApdbGZEcCIIiShX7G+Q9bzgI1FX2KBdE6dYF6E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787244106; c=relaxed/simple; bh=kABHobpwdhkp5oCfj9cG8L36zdeprET71UoWKI81S6c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i93weXKCI7L2YmMNt1uZUrjA/4m8YgWzpY+l7Y52QksNcP0kdcy2YLLdWLTmAXFPGBcR2/+KPxIt0smYTy7lOA+ymr95jgcl6cISB3THun4qM109Io7IJghYqmtama2v2iA+vD3cud+S0inljctLxk+tXGmOtFoI1YeBnq1m+10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=j8qbcla8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="j8qbcla8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 881E81F000E9; Thu, 20 Aug 2026 16:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787244105; bh=ozOb7/yo9boISy47BdwykvnuNK3hejqRRiDCwAXjTck=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=j8qbcla8LAsHAnaZKHd0jntZxizp75II3FpXZPoE/or6IqH3pwbwuRwCSj/dNJZsy EGfkC1UURcIxHZhILXH23PCv1bTiQfzutJ7IwZHe4dmvcIJN7xrgD78yWRe5jbGuD5 j6cz+yxO6mwZ0haHi2sU7Uz3AmrUXBhzqjOUjIyw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Dmitry Torokhov , Sasha Levin Subject: [PATCH 5.10 051/235] Input: mms114 - reject an oversized device packet size Date: Thu, 20 Aug 2026 16:54:47 +0200 Message-ID: <20260820145217.983453289@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145216.426568665@linuxfoundation.org> References: <20260820145216.426568665@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas [ Upstream commit 66725039f7090afe14c31bd259e2059a68f04023 ] mms114_interrupt() reads a packet of touch data from the device into a fixed-size on-stack buffer struct mms114_touch touch[MMS114_MAX_TOUCH]; which holds MMS114_MAX_TOUCH (10) events of MMS114_EVENT_SIZE (8) bytes, i.e. 80 bytes. The length of the I2C read into it is taken verbatim from the device: packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE); if (packet_size <= 0) goto out; ... error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size, (u8 *)touch); packet_size is a single device register byte (0x0F) and the only check is the lower bound packet_size <= 0; it is never bounded against the size of touch[]. A malfunctioning, malicious or counterfeit controller (or an attacker tampering with the I2C bus) can report a packet_size of up to 255, so __mms114_read_reg() writes up to 175 bytes past the end of touch[] on the IRQ-thread stack: a stack out-of-bounds write that can overwrite the stack canary, saved registers and the return address. A well-formed device never reports more than the buffer holds, so reject an oversized packet and drop the report, consistent with the handler's other error paths, rather than reading past the buffer. Fixes: 07b8481d4aff ("Input: add MELFAS mms114 touchscreen driver") Signed-off-by: Bryam Vargas Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260612-b4-disp-dc4b8dc4-v1-1-d7cb0a828d92@proton.me Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/input/touchscreen/mms114.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/input/touchscreen/mms114.c +++ b/drivers/input/touchscreen/mms114.c @@ -209,6 +209,12 @@ static irqreturn_t mms114_interrupt(int if (packet_size <= 0) goto out; + if (packet_size > sizeof(touch)) { + dev_err(&data->client->dev, "Invalid packet size %d (max %zu)\n", + packet_size, sizeof(touch)); + goto out; + } + touch_size = packet_size / MMS114_PACKET_NUM; error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size,