linux-cve-announce - CVE-2022-50679: i40e: Fix DMA mappings leak

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Message-ID: <2025120949-CVE-2022-50679-b2b8@gregkh>
Date: Tue,  9 Dec 2025 10:31:04 +0900
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2022-50679: i40e: Fix DMA mappings leak

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

i40e: Fix DMA mappings leak

During reallocation of RX buffers, new DMA mappings are created for
those buffers.

steps for reproduction:
while :
do
for ((i=0; i<=8160; i=i+32))
do
ethtool -G enp130s0f0 rx $i tx $i
sleep 0.5
ethtool -g enp130s0f0
done
done

This resulted in crash:
i40e 0000:01:00.1: Unable to allocate memory for the Rx descriptor ring, size=65536
Driver BUG
WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:141 xdp_rxq_info_unreg+0x43/0x50
Call Trace:
i40e_free_rx_resources+0x70/0x80 [i40e]
i40e_set_ringparam+0x27c/0x800 [i40e]
ethnl_set_rings+0x1b2/0x290
genl_family_rcv_msg_doit.isra.15+0x10f/0x150
genl_family_rcv_msg+0xb3/0x160
? rings_fill_reply+0x1a0/0x1a0
genl_rcv_msg+0x47/0x90
? genl_family_rcv_msg+0x160/0x160
netlink_rcv_skb+0x4c/0x120
genl_rcv+0x24/0x40
netlink_unicast+0x196/0x230
netlink_sendmsg+0x204/0x3d0
sock_sendmsg+0x4c/0x50
__sys_sendto+0xee/0x160
? handle_mm_fault+0xbe/0x1e0
? syscall_trace_enter+0x1d3/0x2c0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x5b/0x1a0
entry_SYSCALL_64_after_hwframe+0x65/0xca
RIP: 0033:0x7f5eac8b035b
Missing register, driver bug
WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:119 xdp_rxq_info_unreg_mem_model+0x69/0x140
Call Trace:
xdp_rxq_info_unreg+0x1e/0x50
i40e_free_rx_resources+0x70/0x80 [i40e]
i40e_set_ringparam+0x27c/0x800 [i40e]
ethnl_set_rings+0x1b2/0x290
genl_family_rcv_msg_doit.isra.15+0x10f/0x150
genl_family_rcv_msg+0xb3/0x160
? rings_fill_reply+0x1a0/0x1a0
genl_rcv_msg+0x47/0x90
? genl_family_rcv_msg+0x160/0x160
netlink_rcv_skb+0x4c/0x120
genl_rcv+0x24/0x40
netlink_unicast+0x196/0x230
netlink_sendmsg+0x204/0x3d0
sock_sendmsg+0x4c/0x50
__sys_sendto+0xee/0x160
? handle_mm_fault+0xbe/0x1e0
? syscall_trace_enter+0x1d3/0x2c0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x5b/0x1a0
entry_SYSCALL_64_after_hwframe+0x65/0xca
RIP: 0033:0x7f5eac8b035b

This was caused because of new buffers with different RX ring count should
substitute older ones, but those buffers were freed in
i40e_configure_rx_ring and reallocated again with i40e_alloc_rx_bi,
thus kfree on rx_bi caused leak of already mapped DMA.

Fix this by reallocating ZC with rx_bi_zc struct when BPF program loads. Additionally
reallocate back to rx_bi when BPF program unloads.

If BPF program is loaded/unloaded and XSK pools are created, reallocate
RX queues accordingly in XSP_SETUP_XSK_POOL handler.

The Linux kernel CVE team has assigned CVE-2022-50679 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.8 with commit be1222b585fdc410b8c1dbcc57dd03a00f04eff5 and fixed in 5.10.152 with commit ed5baf3d0a33caaca4cd4073ebb0854cc77a616d
	Issue introduced in 5.8 with commit be1222b585fdc410b8c1dbcc57dd03a00f04eff5 and fixed in 5.15.76 with commit 94a171c982b8a8137a00721c1e62bc2713435bca
	Issue introduced in 5.8 with commit be1222b585fdc410b8c1dbcc57dd03a00f04eff5 and fixed in 6.0.6 with commit 5f499596dfa3db9b3172645b6de9e1096a669c95
	Issue introduced in 5.8 with commit be1222b585fdc410b8c1dbcc57dd03a00f04eff5 and fixed in 6.1 with commit aae425efdfd1b1d8452260a3cb49344ebf20b1f5

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-50679
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/intel/i40e/i40e_ethtool.c
	drivers/net/ethernet/intel/i40e/i40e_main.c
	drivers/net/ethernet/intel/i40e/i40e_txrx.c
	drivers/net/ethernet/intel/i40e/i40e_txrx.h
	drivers/net/ethernet/intel/i40e/i40e_xsk.c
	drivers/net/ethernet/intel/i40e/i40e_xsk.h


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/ed5baf3d0a33caaca4cd4073ebb0854cc77a616d
	https://git.kernel.org/stable/c/94a171c982b8a8137a00721c1e62bc2713435bca
	https://git.kernel.org/stable/c/5f499596dfa3db9b3172645b6de9e1096a669c95
	https://git.kernel.org/stable/c/aae425efdfd1b1d8452260a3cb49344ebf20b1f5