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 DA66D375ACC for ; Sat, 28 Feb 2026 18:00:13 +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=1772301613; cv=none; b=jkiz1NoWBX2VH3r51pZNn0hF2tguiPumWCSRUnuPv04Xl3beAPnnqHQUDIDQ6f5YgXPjH7/q/2mazmqnU8fAE/vH0zjZGbd+M8qJGFdIRdV+OBVwqkmV72Nk1FN9vmI7T//ZtkjolpWUfFdI6XOISuBu/UW56+PS6mVkKOWRW9I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772301613; c=relaxed/simple; bh=dngh46TmnsNASgHmfYC2rE5viEdiSU9GGLGhzsepmS8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GjGwUArNIZbPZHCml5OI1Hras1+8Vx67z6TNh5bdyX0xkagPRRvYAX9+6v2RnI66CkokOe1l9+xGozOJzezVDHFzHIvJMpW666OGldC/y91NXEDTA3QoIz55DSQkjGCaE+Wj3zWYNxnCUWsaxyNieSVdma63zspPjekDj+9XVWY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y67xqsuz; 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="Y67xqsuz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32F59C2BC9E; Sat, 28 Feb 2026 18:00:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772301613; bh=dngh46TmnsNASgHmfYC2rE5viEdiSU9GGLGhzsepmS8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y67xqsuz3EjXMQp8rC5sK+tfIVUYwKVeJCX3c3UgazzIW/QMshQnVNNxdIR/3w7wf 1FgdBB6Elcys0AcNpvd8X/lFsbv8wvq3H9cC//x7kipEW60rNVqhE0576zNQm8PVdt CzYUyMpuCLoRmxWc96NIGI6W/raWWErw8S0pOZm7dNy7yrZ20hA039E0KELzKAMz7F K2+6AAkFleFRzax4tz1zEVq7l2MGpoFer87bODkE2xJG4yxOrXenslXOrx2TmKto5h W8/XKL32mywC50AJkYK3fiQtK1fBGLo0ltPb/105X8H80tX4eqfUnc7K0ED6n4lHAq mH0bnFSySLeyQ== From: Sasha Levin To: patches@lists.linux.dev Cc: YunJe Shin , YunJe Shin , Leon Romanovsky , Greg Kroah-Hartman Subject: [PATCH 6.12 002/385] RDMA/umad: Reject negative data_len in ib_umad_write Date: Sat, 28 Feb 2026 12:53:44 -0500 Message-ID: <20260228180011.1568201-2-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228180011.1568201-1-sashal@kernel.org> References: <20260228180011.1568201-1-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 fd67fc9fe85a4..2f7e3c4483fc5 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