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 7F6CB42FCD8; Thu, 16 Jul 2026 14:34:23 +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=1784212464; cv=none; b=Jw1mAZDvQIb1nQLXV2s7jvT4ISSOBKdj6PjZJMYMkjrdoPMrt3lMtKkKNx8Qzveh/B0CHJ8d2ofGHotPk4+86kgEDcfMopg16KrfXtcLncqK4rkWyigTIvalJMQtvCKQncqUumO36NGBeTvFk5oa5vTzRJCuXcgFdVmlU9MP80Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212464; c=relaxed/simple; bh=MV1SwSJRBIU0r1bO3cCtpeJcqVrH/P2gsangkQZ/JFo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lpy8B/n/VP1nTfmUc0Ml7lbloAFYE31n8hQqTbgqnLmfz/FJ8mpB3ZmqshTHczLVZfjIfnWssLwF36WQ5Z4PIuukOwJ4AGQDb4a5ThwTzDaR+CKmS1cp6AFLXfB2tE42bCThd2UMHa4M90l3Oh88OaaSK93ms8gq5NiaV0PzLrU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tkbY4VN7; 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="tkbY4VN7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 757021F000E9; Thu, 16 Jul 2026 14:34:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784212463; bh=ef+2h7ec8IrFcxEJJjE2BRDUlP88rIoAMI2mxMgLh5A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=tkbY4VN73QIsnspYJJ5VYBOvJ/uwSwmhsm8Y2EYm2SrqCPDZOEtXvwbuac2nuqL9P 971RTBpy/43v/de6+JwoL/MtmS2wZZBO6lVmFwjaO0q3g+sBkcvYqAtVrXT7A9cSt+ W8Xh7pwxpVuYFrCwyM1LCdu34Scz6J5H1Huc4xT8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Dmitry Torokhov Subject: [PATCH 6.12 338/349] Input: mms114 - reject an oversized device packet size Date: Thu, 16 Jul 2026 15:34:32 +0200 Message-ID: <20260716133040.873619923@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit 66725039f7090afe14c31bd259e2059a68f04023 upstream. 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: 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 @@ -236,6 +236,12 @@ static irqreturn_t mms114_interrupt(int if (packet_size <= 0) goto out; + if (packet_size > sizeof(touch)) { + dev_err(&client->dev, "Invalid packet size %d (max %zu)\n", + packet_size, sizeof(touch)); + goto out; + } + /* MMS136 has slightly different event size */ if (data->type == TYPE_MMS134S || data->type == TYPE_MMS136) event_size = MMS136_EVENT_SIZE;