From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DF8D31D5141; Wed, 25 Feb 2026 01:42:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983722; cv=none; b=KAmHQ0Aj3LpjmDByJEvCdTaPC0ES5WTWc5D012ew3vKn8kqZotIQb2UyT+UJQMHZRA3vXkD2cMTS0KnqrhdSp87IQ61wr//8EhwSuY2ZPrz1Yu/s1RPglvgKeiIfMnwIombTGfLaunjz5apdqZ67HefchsjrXbJ/lpFNLGlPNI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983722; c=relaxed/simple; bh=QeTEYCHNKAMoXnIY/Yhge/lBbPcGfjPP7fTWHK/+g9I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fowgymDqbGpSZKWSxVZmzKY+2qQaHOREBsxWhqBVN/5gyk272wDvKewe3rhrxI4ofU2qywNEL/9BzVtg2pYq98rjgwQzRo3r43+fsIUppBFtMWsupHmryFBCg2VhxeukYvrED0Fq7qKzVxbAwAGkUpbt/Y7xiZrs9SB6zgsi5IU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ER2D4jIk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ER2D4jIk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B68B4C19424; Wed, 25 Feb 2026 01:42:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983722; bh=QeTEYCHNKAMoXnIY/Yhge/lBbPcGfjPP7fTWHK/+g9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ER2D4jIkdzlRpjbiG9W4dzyjB2tHwa8lEsLlSOShmZNWg4QuKevM+eAvvkplws3NJ O7UBbVulwF6Xs2XDqm9cpGEWvrXc4rtPMBTQFHQ4KtdHIzaCUxOWHLMRxHq00mRD/F jH6ctbOZgGp2chUM85zBE8efk2CEPcltOasxnrIc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, YunJe Shin , Leon Romanovsky Subject: [PATCH 6.18 002/641] RDMA/umad: Reject negative data_len in ib_umad_write Date: Tue, 24 Feb 2026 17:15:28 -0800 Message-ID: <20260225012348.986046651@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: YunJe Shin commit 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2 upstream. ib_umad_write computes data_len from user-controlled count and the MAD header sizes. With a mismatched user MAD header size and RMPP header length, data_len can become negative and reach ib_create_send_mad(). This can make the padding calculation exceed the segment size and trigger an out-of-bounds memset in alloc_send_rmpp_list(). Add an explicit check to reject negative data_len before creating the send buffer. KASAN splat: [ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0 [ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102 [ 211.365867] ib_create_send_mad+0xa01/0x11b0 [ 211.365887] ib_umad_write+0x853/0x1c80 Fixes: 2be8e3ee8efd ("IB/umad: Add P_Key index support") Signed-off-by: YunJe Shin Link: https://patch.msgid.link/20260203100628.1215408-1-ioerts@kookmin.ac.kr Signed-off-by: Leon Romanovsky Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/user_mad.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/infiniband/core/user_mad.c +++ b/drivers/infiniband/core/user_mad.c @@ -514,7 +514,8 @@ static ssize_t ib_umad_write(struct file struct rdma_ah_attr ah_attr; struct ib_ah *ah; __be64 *tid; - int ret, data_len, hdr_len, copy_offset, rmpp_active; + int ret, hdr_len, copy_offset, rmpp_active; + size_t data_len; u8 base_version; if (count < hdr_size(file) + IB_MGMT_RMPP_HDR) @@ -588,7 +589,10 @@ static ssize_t ib_umad_write(struct file } base_version = ((struct ib_mad_hdr *)&packet->mad.data)->base_version; - data_len = count - hdr_size(file) - hdr_len; + if (check_sub_overflow(count, hdr_size(file) + hdr_len, &data_len)) { + ret = -EINVAL; + goto err_ah; + } packet->msg = ib_create_send_mad(agent, be32_to_cpu(packet->mad.hdr.qpn), packet->mad.hdr.pkey_index, rmpp_active,