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 20EB13546F6; Sat, 30 May 2026 17:39:28 +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=1780162769; cv=none; b=egMZHueKsqHV2lS82QEy+Jbh5vHYORw1q5AD8+b4Vp9CR8kfuj5DCNNPsEwev2BYrs43U5aWjjWYVI1HrLA6mZvEMHPhdhsoa/Lqsje8yBg5KaGTZ3dd75xRU+HMrRa7CcC2Qb9xLvvW/y6a8icMWG9tAJxGGPu+2Jkl/UPNNFo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162769; c=relaxed/simple; bh=PHbczj71JcOloK8zIujSV13MdU7lKZhb0QMSvdhsZzs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ifIDDZ6FUGCpWPMrHJUIbbdJgmWucM4wDzA5Brg/idAo+9zjOGIonZ/y0iwnIg6Vve15oFkKai0AeQQAfH7eouiBVIOK7Z594/2s35MNMcErM0pxReNOERnE5oFW47oS1+Iv4Mwy3MS4Ix0M9NX6dicjjzrlp5hu6AU2DUSBpSw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sbXEH0P5; 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="sbXEH0P5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65A831F00893; Sat, 30 May 2026 17:39:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162768; bh=JCVPb2GafcP5w/oGI6cz3+j0hgteyJIwAPCidkDncwk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sbXEH0P5Yuy+MX53YgC7lvjM1aQ1pAlVW0O/TEsAm9GALJcp7kJihwv5tJcUrX12Q kizqXDoSj/J7YSDGuASMTw7YQWIGjLsGERrm1ksDIijAZz3elfXf4KU9UTyzPjj0FZ 1q/gLCetebb5nwoTDbnfZtkQsySM5zCWOYCjOYx8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Jiri Kosina , Benjamin Tissoires , linux-input@vger.kernel.org, Jiri Kosina Subject: [PATCH 5.15 057/776] HID: core: clamp report_size in s32ton() to avoid undefined shift Date: Sat, 30 May 2026 17:56:11 +0200 Message-ID: <20260530160241.788645123@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org 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: Greg Kroah-Hartman commit 69c02ffde6ed4d535fa4e693a9e572729cad3d0d upstream. s32ton() shifts by n-1 where n is the field's report_size, a value that comes directly from a HID device. The HID parser bounds report_size only to <= 256, so a broken HID device can supply a report descriptor with a wide field that triggers shift exponents up to 256 on a 32-bit type when an output report is built via hid_output_field() or hid_set_field(). Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in hid_report_raw_event") added the same n > 32 clamp to the function snto32(), but s32ton() was never given the same fix as I guess syzbot hadn't figured out how to fuzz a device the same way. Fix this up by just clamping the max value of n, just like snto32() does. Cc: stable Cc: Jiri Kosina Cc: Benjamin Tissoires Cc: linux-input@vger.kernel.org Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-core.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1354,6 +1354,9 @@ static u32 s32ton(__s32 value, unsigned if (!value || !n) return 0; + if (n > 32) + n = 32; + a = value >> (n - 1); if (a && a != -1) return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;