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 4E1265187F2; Wed, 30 Sep 2026 18:23:19 +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=1790792600; cv=none; b=csI54K2xPIG9clDqteHeyyLpj2KT0tWajN8m5Kwf+1PR2cq8mJSqItOan4UPml7+eflXoBIApboSbpCqUcBWw0o+IV/80vrMNVcWmwDIGImxl9uU/oJIBBFYNJMMiFbVKRDE++LzSndrC2wb8GWoA+Acw8gfX8UvqFKudo+Xy5c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792600; c=relaxed/simple; bh=Jfs2NlsbVysTwggML7uzSFUbycWT+86HAp1rou68fSw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P/PfsYcBxSjRvRiA78K+KxwvIA+1iQFkAgpMgo9baLo44K5tAe1AXMFZ7Hbh+Gw4WLhAShizkky69X0Xv4bsH+W21dTs7cQbIqdCW2Sn9GlWPx2Pht64ZI5/apxEy5hXz0HhZ2ncAIM4EBibgYvkfx804/8v1NIJfbMtvtO1b2Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sJ/EImh3; 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="sJ/EImh3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 733631F000FF; Wed, 30 Sep 2026 18:23:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792599; bh=cHchR0m5otfOYCXllnAsVYgqwkbbgVhQK755hfWUflY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sJ/EImh391+qYOgxvMnzghNXwp71APagKamGVFnBa6BF1LqsT16lB52RWuwJJrBky ARgdBPzFfZeW3iRQS+nZ2lyd30XPMOBUlSzQY8u17cyBJAHfqeakfBK4oXOC7DgQGu U4O/S2NYg5ThM7rUzszGBsNs4d2HoGLsqrhTJ3Zc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chen Changcheng , Jiri Kosina Subject: [PATCH 5.15 713/752] HID: alps: fix use-after-free on input2 registration failure Date: Wed, 30 Sep 2026 17:29:43 +0200 Message-ID: <20260930152413.656646532@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-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chen Changcheng commit d3aba3442798ce4a4c8ce3104d7b286d61e605f9 upstream. alps_input_configured() stores data->input2 before calling input_register_device(). If registration fails, input_free_device() frees the input device but data->input2 still points to the freed memory. alps_input_configured() calls hid_hw_open() before allocating input2, so URBs are already active and raw_event can fire during the failure window. A U1_SP_ABSOLUTE_REPORT_ID report arriving then causes u1_raw_event() to dereference the freed data->input2 -> use-after-free. Fix by only storing input2 into drvdata after successful registration and adding a NULL guard in the raw_event path. Fixes: 2562756dde55 ("HID: add Alps I2C HID Touchpad-Stick support") Cc: stable@vger.kernel.org Signed-off-by: Chen Changcheng Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-alps.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/hid/hid-alps.c +++ b/drivers/hid/hid-alps.c @@ -407,6 +407,8 @@ static int u1_raw_event(struct alps_dev return 1; case U1_SP_ABSOLUTE_REPORT_ID: + if (!hdata->input2) + return 0; sp_x = get_unaligned_le16(data+2); sp_y = get_unaligned_le16(data+4); @@ -738,7 +740,6 @@ static int alps_input_configured(struct goto exit; } - data->input2 = input2; input2->phys = input->phys; input2->name = "DualPoint Stick"; input2->id.bustype = BUS_I2C; @@ -762,11 +763,12 @@ static int alps_input_configured(struct __set_bit(INPUT_PROP_POINTER, input2->propbit); __set_bit(INPUT_PROP_POINTING_STICK, input2->propbit); - if (input_register_device(data->input2)) { + if (input_register_device(input2)) { input_free_device(input2); ret = -ENOENT; goto exit; } + data->input2 = input2; } exit: