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 35EE82DFA3A for ; Sat, 28 Feb 2026 18:15:08 +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=1772302508; cv=none; b=GWoJH35u/Xv203B8XaAys4UEuyqq4Mx2Uap/ZvY4QSLs3EwablNICSThntD0r1Lgk2dxHF6TiThIq5+gUU/iTPvlmxvlNxvglvJ2znIjtYJUAsXDxqN0G1wvNa7XcwoN1kdnV57txs92pTOkodSU11FufXyvBazFA2qugmi8dQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302508; c=relaxed/simple; bh=akVzfs7NDCP60jDfg+c8ln0ANGcWETGZIJA5Ko2us9w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LYb5XtVPvZ3E1Z9OV5hA145fxj8LNFoXx+72CCqLyO31hapB4P7/Uf28qq8SqzRH0Je0W1fKQedb/XvB6NMlp0veEazSpiQuN0oSc0nSl4gqNqWfDpFgnQmQ23UEROnBgQOLIJS6lRw86AUQJy0xLAV7rQQ+RyOmRvHun8tavHM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ckJx/dmL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ckJx/dmL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 680EDC19425; Sat, 28 Feb 2026 18:15:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302508; bh=akVzfs7NDCP60jDfg+c8ln0ANGcWETGZIJA5Ko2us9w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ckJx/dmL0XLeuThZ+wE3sIcah0Ipd9raRZuVi3nfR5yi5fmGfqgGxmNx9pjL/UDj5 fClPaVT0OJjuDeUy1kH2Ob9hQvHsRIWPqrojxqbhIP19RID3jE54KOvlRSqAwegO0T g8jmO8t//nqLbmF7BC+dmzYq02kR56aYk+SiYGTq9H8aoLvgQhXNs6roKrts+tUmie kwN8ZoP/HxfykOMwlJvVNHTM5UzalV0/+PPvcEDiIXpmRPo2frcEGGI7PAvAoJAFMP +ORLXz3T4lKihOxnjawZJz6JrW95r2D7z1DeSYjZ+E1GCCG3kcZCQidzOQL8OU9iiB yLGg/FzxGl4ug== From: Sasha Levin To: patches@lists.linux.dev Cc: YunJe Shin , YunJe Shin , Leon Romanovsky , Greg Kroah-Hartman Subject: [PATCH 5.15 002/164] RDMA/umad: Reject negative data_len in ib_umad_write Date: Sat, 28 Feb 2026 13:12:21 -0500 Message-ID: <20260228181505.1600663-2-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228181505.1600663-1-sashal@kernel.org> References: <20260228181505.1600663-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit 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(-) diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c index 66a0c5a73b832..03e94ef2d9227 100644 --- 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 *filp, const char __user *buf, 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 *filp, const char __user *buf, } 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, -- 2.51.0