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 E288737CD5A; Thu, 20 Aug 2026 16:26:31 +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=1787243193; cv=none; b=lVQTsRJ/KgbwVRCmkyIJdY7JGncojmqNvMxkrhklx+1IWCBG3Ejes5RQBU2WVdnWs8GCLe7WvSwn+0ig2r+s6ky2F9btEcRE+hjWpoXZhVZWFQLDqZ9tBsBFBOg8qtN1a4+FgLNCYblCWevCnuchPkMsIMddYSihxe7VHC3jGl0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787243193; c=relaxed/simple; bh=emYYQd0OMiqatBUdL4+qBWhLPNHpzEMs/peoy5rDzB0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YsN+szbukB66cJpjgExSWo3tTVr/sUDf5S67LfuOUjVPLDNw1s4+Con4rlqU/0UFbXmKaNwGvls2bt9EPUruAJZDQMaInuSj5M1+ueu0Rx5JE8Rj0Ha0lidQsiA/DK2vt0SsadNXW9crHNzigE/a/lzEkLB0Kq/W2dNXUOn1SUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Z1Uz1bZ/; 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="Z1Uz1bZ/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49EDF1F000E9; Thu, 20 Aug 2026 16:26:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787243191; bh=GhVoT/6LWtUY2vQTyaBhTowpSsf19NYX713gv3LizMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Z1Uz1bZ/hNTlu9PwF43zjJfyJRs5VkyzivR46GpKTlqPGpnOu2j3zveKJdEKjTGg5 9QggHJTPuRFAXo932ub2lTSbLiKLQHZi/DfvqhIeVFfi8reLZOsHOQ4u44ZbfpMudp 8/70B0ubcJwmouSc4JuhoeZDMXCwuuePRImrNZqI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexandra Winter , Hidayath Khan , Joe Damato , Jakub Kicinski Subject: [PATCH 5.15 010/272] s390/qeth: validate user buffer length in SNMP and ARP query ioctls Date: Thu, 20 Aug 2026 16:53:14 +0200 Message-ID: <20260820145231.546380188@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145231.229664293@linuxfoundation.org> References: <20260820145231.229664293@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: Hidayath Khan commit d141f087b1af656f055d7c5793a3e87817ba0bbe upstream. qeth_snmp_command() and qeth_l3_arp_query() allocate a buffer sized by a user-supplied length (udata_len) without checking a lower bound, then set udata_offset to a fixed non-zero value and pass both to a reply callback. The callback bounds-checks the copy with if ((udata_len - udata_offset) < len) Both fields are u32, so a udata_len smaller than udata_offset makes the subtraction wrap and the check pass, and the following memcpy() writes past the allocation. A udata_len of 0 also yields ZERO_SIZE_PTR from kzalloc(), which the existing NULL check does not catch. Reject buffers smaller than udata_offset before allocating, so the callback subtraction can no longer underflow. Fixes: 4a71df50047f ("qeth: new qeth device driver") Cc: stable@vger.kernel.org Reviewed-by: Alexandra Winter Signed-off-by: Hidayath Khan Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260730142216.218309-1-hidayath@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/s390/net/qeth_core_main.c | 3 +++ drivers/s390/net/qeth_l3_main.c | 5 +++++ 2 files changed, 8 insertions(+) --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -4674,6 +4674,9 @@ static int qeth_snmp_command(struct qeth if (req_len > QETH_BUFSIZE) return -EINVAL; + if (qinfo.udata_len < sizeof(struct qeth_snmp_ureq_hdr)) + return -EINVAL; + iob = qeth_get_adapter_cmd(card, IPA_SETADP_SET_SNMP_CONTROL, req_len); if (!iob) return -ENOMEM; --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -1415,6 +1415,11 @@ static int qeth_l3_arp_query(struct qeth rc = -EFAULT; goto out; } + + if (qinfo.udata_len < QETH_QARP_ENTRIES_OFFSET) { + rc = -EINVAL; + goto out; + } qinfo.udata = kzalloc(qinfo.udata_len, GFP_KERNEL); if (!qinfo.udata) { rc = -ENOMEM;