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 3AE1D25393E; Tue, 25 Aug 2026 13:58:28 +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=1787666309; cv=none; b=a7RBvutUOwmrAJW/2wjLhThEKMJ/OSXDZZ95Fpp6+Xq8QWy8U94Fln1WKwyLtoE/0z7W4lgpdyFQxq7G6c3w5GQl3pCQrd/k9Hv20kMZzbadqSdseMzhTpbjYgVTPEJUyi8fe91vCxiJZ/WNwHdp5S68ylTVGbpr/bagzluVqNQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787666309; c=relaxed/simple; bh=BGW01clQ+TEVRWPOmU4h2q/CoDHaTZL08FPsf0kd/bM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sue+i/qKlSLIR4I3YHiZBTmks26xmBKmmGsLdwE4vJrgwMZicrtQNJcf2/ymq3foeILIpsFjwycnceSm0yy538333moD9WxMjkekJpUt6ZTGYMvxBfX2ZCzBhR4JPgKlMfQoFMHGO+fIsEupo9bXcXrbsDKwZEuImtk5w/7ecaw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=k0o+98ZR; 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="k0o+98ZR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E0171F000E9; Tue, 25 Aug 2026 13:58:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787666308; bh=aZ6MSqUtkpTFD+XcxE3qJLX3r6TZd5xkW9Zt1nWNZV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=k0o+98ZRhko7CnrG4l2T7prY5u/ugSeCnQ+OYqEmgdvlQwHTKVCch2hSLZdJjxThr lbBI/HLEl0oMkSizYdavRy7vDsiJghjClQouZwgzECOfqSb4spht6VCegnm9C4EKbP kL3at9S1TFEy5CqdTzdtOWy/xEHW9vkDmDUD8ACc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jann Horn , Jiri Kosina Subject: [PATCH 5.15 74/76] HID: core: fix number/pointer type confusion on long items Date: Tue, 25 Aug 2026 15:27:07 +0200 Message-ID: <20260825132544.455884292@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.568214149@linuxfoundation.org> References: <20260825132541.568214149@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: Jann Horn commit 28abce951343fcec26e397610868efa4e1395c3f upstream. When fetch_item() is called by hid_scan_report() on an item with HID_ITEM_TAG_LONG, it stores a pointer to the item data in item->data.longdata instead of storing a value directly in item->data.{u8/u16/u32}. When item_udata() or item_sdata() encounters such an item, it incorrectly assumes that the item is in short format, and therefore returns the lower part of a kernel pointer reinterpreted as a number. When a HID device is connected whose descriptor contains a HID_GLOBAL_ITEM_TAG_REPORT_SIZE encoded in long format with size=4, this causes the lower half of a kernel pointer to be printed into dmesg as a number, like this: hid (null): invalid report_size 107953555 To fix it, let item_udata() and item_sdata() verify that the item is in short format. Note that this bug only affects hid_scan_report(), while the main parsing pass hid_parse_collections() will always bail out when encountering a long item. Sidenote: There are currently no users of data.longdata; maybe we should just remove any parsing of long-format descriptors as a follow-up. Fixes: 3dc8fc083dbf ("HID: Use hid_parser for pre-scanning the report descriptors") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-core.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -346,6 +346,9 @@ static int hid_add_field(struct hid_pars static u32 item_udata(struct hid_item *item) { + if (item->format != HID_ITEM_FORMAT_SHORT) + return 0; + switch (item->size) { case 1: return item->data.u8; case 2: return item->data.u16; @@ -356,6 +359,9 @@ static u32 item_udata(struct hid_item *i static s32 item_sdata(struct hid_item *item) { + if (item->format != HID_ITEM_FORMAT_SHORT) + return 0; + switch (item->size) { case 1: return item->data.s8; case 2: return item->data.s16;