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 BA53F360745; Thu, 20 Aug 2026 15:11:56 +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=1787238717; cv=none; b=BY9FKSZjmfDKH0comdKvsvya69NGEXAyRZc4zqc9qzWhtACwvw2qqKgnBNV1SrstpnxBBkNxYW22dsGa5nwjt4Qoslzaok8JZz0fps1iSt8fl80RoERYeL/runr28FyF5UmdCfgF2q2v7hO7ZnG+W6ZLnFTuBKXLsQOXi6k66Os= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787238717; c=relaxed/simple; bh=esdX+Tj6mDWg2WBR3g7QHo0tcS8ypGjgg47m4e0IkK0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ulSGn4NVFae0U7DBh5Kkcv8YJ6rv3PYngNt68YU9jqaNms381a3oHB4FZu5gw1LEM+Ip7Z+kAVmwEt1I3/Lrrmu6LN8SDyMDGhiZyxKuaUL11dKUiAfFpQj1ftcg7ZV55zSVpldQS7/ij+gknbRQ9qzD8mWMUkW9OSPNY4qVKMk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vv4cK907; 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="vv4cK907" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 205071F000E9; Thu, 20 Aug 2026 15:11:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787238716; bh=HnsMKlKrRMDEG7Zx/DqBI8sIDVBWQqi7eZ/5wbW/vhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vv4cK907RuhlHPhAVOcoBQoSrnlAI0gEZLzhgAh/D35Ltq0czR1aH4aXAgPndtchP DsdlrKrV+E92Xb8hdhRdWuYxAsr3ixXsu1doKVVEz0RRjpFl/h3kxmCJ9sD5mpW4GW KvbRojQcMXEHuQas1/4RTUVP/+V4tloGZcgP9TMM= 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 6.18 017/217] s390/qeth: validate user buffer length in SNMP and ARP query ioctls Date: Thu, 20 Aug 2026 16:53:05 +0200 Message-ID: <20260820145238.145013414@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145237.531699751@linuxfoundation.org> References: <20260820145237.531699751@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 6.18-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 @@ -4712,6 +4712,9 @@ 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 @@ -1416,6 +1416,11 @@ 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;