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 A8E37511225; Wed, 30 Sep 2026 18:18:19 +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=1790792300; cv=none; b=iyoI5QiK84ZiILC8mn6GgVUqBQ0hXU2WY2ilsNFRpeZDBNYN72toFPOCmTitI+LgWTCHp1ND4wYsUg/0IIB9dWvdSXuloLgxholwfA/XgJR7607aDt5nRVFMHq0jklqWAh/0t9BDhRvRtRxpejdwWvGFSGbfQIGFBFsMlHH3Xco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792300; c=relaxed/simple; bh=IVIpfcIlE6xTlz/lhurth0otbxpM80Y2PevGPdzBIpM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CoqvkO+hH6rLZ1Xw6ptlZ/X1oODiLM5AmUbg6qhIECNhdgKz95uzPDLjs3a6lTY0Se4sQ7JnX6Y2xpmcMvfX/bPGN06QVrEIA5lbEBPUhbsO+R8ilNwTFkG3a9cij8XPSQjP1C2WzZQlS2LlQ5ozFROU/COsqMlCAMmDFcd37FI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OubVb9jr; 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="OubVb9jr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06CEB1F000FF; Wed, 30 Sep 2026 18:18:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792299; bh=gxKrsSHPUUFjG7k24FUP1yn5ACIY2cN7+ovRQIzJOnQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OubVb9jrcPmNZLuA5ZfqPXXDP0svSuhhSN/OoAYDLn9YtgWcNugvqMChkxjbRhbCm wLBrukYzaBCJ0KMM2LHw0OMqlnwRgKbN35DMgqOW28gXb9Z0HEQ2iJbZRVFlwAh+nx vy2VrvhxMsJOWwBcAooLS2cmKjlAlUXOhnYIARAA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Iv=C3=A1n=20Ezequiel=20Rodriguez?= , Dmitry Torokhov Subject: [PATCH 5.15 561/752] Input: zero ff_effect before compat copy in input_ff_effect_from_user Date: Wed, 30 Sep 2026 17:27:11 +0200 Message-ID: <20260930152410.378870642@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Iván Ezequiel Rodriguez commit f84819ef8d66931ee3998fee3c4f03230f4cb6cc upstream. In the compat path input_ff_effect_from_user() aliases the caller's native struct ff_effect with the smaller struct ff_effect_compat and copies only the compat sized prefix: compat_effect = (struct ff_effect_compat *)effect; if (copy_from_user(compat_effect, buffer, sizeof(struct ff_effect_compat))) The tail of the native structure is never written. Callers pass an uninitialized on-stack object, for example evdev_do_ioctl() for EVIOCSFF, so those bytes keep their previous stack contents. input_ff_upload() then stores the full native structure in ff->effects[id], from where a uinput based force feedback daemon can read it back via UI_BEGIN_FF_UPLOAD, disclosing kernel stack memory to userspace. Zero the effect before the compat copy. Fixes: 2d56f3a32c0e ("Input: refactor evdev 32bit compat to be shareable with uinput") Cc: stable@vger.kernel.org Signed-off-by: Iván Ezequiel Rodriguez Link: https://patch.msgid.link/20260901130629.24078-3-ivanrwcm25@gmail.com Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/input/input-compat.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/input/input-compat.c +++ b/drivers/input/input-compat.c @@ -75,6 +75,8 @@ int input_ff_effect_from_user(const char */ compat_effect = (struct ff_effect_compat *)effect; + memset(effect, 0, sizeof(*effect)); + if (copy_from_user(compat_effect, buffer, sizeof(struct ff_effect_compat))) return -EFAULT;