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 CC62F51CF76; Wed, 23 Sep 2026 14:50:46 +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=1790175048; cv=none; b=XJE9fPJc52Y1KJxpmqzaKirvmKWRHcZ/9k+d4x5VD0jZHrQcDltRx6LNFWpTUOMRH/nZgY+0UQcgDHzFtYO6w6GFgnTnymupPr5lBOCebjwkY/BN9geGcSvM957ZZ70HmRTQJisjQuFuoayIKXGLUjQBG0kn/3TlRYfvK9DITkY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790175048; c=relaxed/simple; bh=XtTEGH3ecdqLVH7VBkEQsBJZds68C+/r/x1Gke85Uw8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=C0Yi0khZaoXT6PJp3bC/HI2Rlz0EzSofLyCrumu0JpsQWE5acQ+GFmugSR/XeBJiflKFjt7QsBWN68mDtzObdWIYmySFVFwLmPwrzCBiVSFWLbdxv9UPhAVeyR54AgRPYz7uQgFIK64vYcKoh15jGSAGeL1WPV1/XSQCyVMPcfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LWmIFlna; 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="LWmIFlna" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 170291F00893; Wed, 23 Sep 2026 14:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790175046; bh=qUWzn+PhMnm6n7W8RvdvkujjEbg1ShcKBUQQAy5UhwI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LWmIFlnaoqaMIZ9f6EuQQ/N/3XbWc6FR10ry+u/LJVRTIhHW5M8IwhfSOdDeB9U6g KB+ZskbzvtD56oik0iw7eqUtxWUbwn6OJQ9vXUboTFKld8NhB3U7z2sVdD9cgzgDn/ XLs63Q+2mDdTqYZJHRst4BMJdP361JPAfU+mLtRk= 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 6.18 305/398] Input: zero ff_effect before compat copy in input_ff_effect_from_user Date: Wed, 23 Sep 2026 16:06:19 +0200 Message-ID: <20260923140651.326637508@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-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 @@ -76,6 +76,8 @@ 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;