Subject: CVE-2024-41036: net: ks8851: Fix deadlock with the SPI chip variant

From: Greg Kroah-Hartman <[email-masked]>

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

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

net: ks8851: Fix deadlock with the SPI chip variant

When SMP is enabled and spinlocks are actually functional then there is
a deadlock with the 'statelock' spinlock between ks8851_start_xmit_spi
and ks8851_irq:

    watchdog: BUG: soft lockup - CPU#0 stuck for 27s!
    call trace:
      queued_spin_lock_slowpath+0x100/0x284
      do_raw_spin_lock+0x34/0x44
      ks8851_start_xmit_spi+0x30/0xb8
      ks8851_start_xmit+0x14/0x20
      netdev_start_xmit+0x40/0x6c
      dev_hard_start_xmit+0x6c/0xbc
      sch_direct_xmit+0xa4/0x22c
      __qdisc_run+0x138/0x3fc
      qdisc_run+0x24/0x3c
      net_tx_action+0xf8/0x130
      handle_softirqs+0x1ac/0x1f0
      __do_softirq+0x14/0x20
      ____do_softirq+0x10/0x1c
      call_on_irq_stack+0x3c/0x58
      do_softirq_own_stack+0x1c/0x28
      __irq_exit_rcu+0x54/0x9c
      irq_exit_rcu+0x10/0x1c
      el1_interrupt+0x38/0x50
      el1h_64_irq_handler+0x18/0x24
      el1h_64_irq+0x64/0x68
      __netif_schedule+0x6c/0x80
      netif_tx_wake_queue+0x38/0x48
      ks8851_irq+0xb8/0x2c8
      irq_thread_fn+0x2c/0x74
      irq_thread+0x10c/0x1b0
      kthread+0xc8/0xd8
      ret_from_fork+0x10/0x20

This issue has not been identified earlier because tests were done on
a device with SMP disabled and so spinlocks were actually NOPs.

Now use spin_(un)lock_bh for TX queue related locking to avoid execution
of softirq work synchronously that would lead to a deadlock.

The Linux kernel CVE team has assigned CVE-2024-41036 to this issue.

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

	Issue introduced in 6.1.70 with commit 1092525155ea and fixed in 6.1.100 with commit a0c69c492f4a
	Issue introduced in 6.6.9 with commit 30302b41ffdc and fixed in 6.6.41 with commit 80ece0013730
	Issue introduced in 6.7 with commit 3dc5d4454545 and fixed in 6.9.10 with commit 10fec0cd0e8f
	Issue introduced in 6.7 with commit 3dc5d4454545 and fixed in 6.10 with commit 0913ec336a6c
	Issue introduced in 5.10.206 with commit 786788bb1396
	Issue introduced in 5.15.146 with commit 7c25c5d72746

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-2024-41036
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/micrel/ks8851_common.c
	drivers/net/ethernet/micrel/ks8851_spi.c

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/a0c69c492f4a8fad52f0a97565241c926160c9a4
	https://git.kernel.org/stable/c/80ece00137300d74642f2038c8fe5440deaf9f05
	https://git.kernel.org/stable/c/10fec0cd0e8f56ff06c46bb24254c7d8f8f2bbf0
	https://git.kernel.org/stable/c/0913ec336a6c0c4a2b296bd9f74f8e41c4c83c8c