CVE-2021-47558

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

net: stmmac: Disable Tx queues when reconfiguring the interface

The Tx queues were not disabled in situations where the driver needed to
stop the interface to apply a new configuration. This could result in a
kernel panic when doing any of the 3 following actions:

• reconfiguring the number of queues (ethtool -L)
• reconfiguring the size of the ring buffers (ethtool -G)
• installing/removing an XDP program (ip l set dev ethX xdp)

Prevent the panic by making sure netif_tx_disable is called when stopping
an interface.

Without this patch, the following kernel panic can be observed when doing
any of the actions above:

Unable to handle kernel paging request at virtual address ffff80001238d040
[…]
Call trace:
dwmac4_set_addr+0x8/0x10
dev_hard_start_xmit+0xe4/0x1ac
sch_direct_xmit+0xe8/0x39c
__dev_queue_xmit+0x3ec/0xaf0
dev_queue_xmit+0x14/0x20
[…]
[ end trace 0000000000000002 ]—