Subject: CVE-2021-47424: i40e: Fix freeing of uninitialized misc IRQ vector

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

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

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

i40e: Fix freeing of uninitialized misc IRQ vector

When VSI set up failed in i40e_probe() as part of PF switch set up
driver was trying to free misc IRQ vectors in
i40e_clear_interrupt_scheme and produced a kernel Oops:

   Trying to free already-free IRQ 266
   WARNING: CPU: 0 PID: 5 at kernel/irq/manage.c:1731 __free_irq+0x9a/0x300
   Workqueue: events work_for_cpu_fn
   RIP: 0010:__free_irq+0x9a/0x300
   Call Trace:
   ? synchronize_irq+0x3a/0xa0
   free_irq+0x2e/0x60
   i40e_clear_interrupt_scheme+0x53/0x190 [i40e]
   i40e_probe.part.108+0x134b/0x1a40 [i40e]
   ? kmem_cache_alloc+0x158/0x1c0
   ? acpi_ut_update_ref_count.part.1+0x8e/0x345
   ? acpi_ut_update_object_reference+0x15e/0x1e2
   ? strstr+0x21/0x70
   ? irq_get_irq_data+0xa/0x20
   ? mp_check_pin_attr+0x13/0xc0
   ? irq_get_irq_data+0xa/0x20
   ? mp_map_pin_to_irq+0xd3/0x2f0
   ? acpi_register_gsi_ioapic+0x93/0x170
   ? pci_conf1_read+0xa4/0x100
   ? pci_bus_read_config_word+0x49/0x70
   ? do_pci_enable_device+0xcc/0x100
   local_pci_probe+0x41/0x90
   work_for_cpu_fn+0x16/0x20
   process_one_work+0x1a7/0x360
   worker_thread+0x1cf/0x390
   ? create_worker+0x1a0/0x1a0
   kthread+0x112/0x130
   ? kthread_flush_work_fn+0x10/0x10
   ret_from_fork+0x1f/0x40

The problem is that at that point misc IRQ vectors
were not allocated yet and we get a call trace
that driver is trying to free already free IRQ vectors.

Add a check in i40e_clear_interrupt_scheme for __I40E_MISC_IRQ_REQUESTED
PF state before calling i40e_free_misc_vector. This state is set only if
misc IRQ vectors were properly initialized.

The Linux kernel CVE team has assigned CVE-2021-47424 to this issue.

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

	Issue introduced in 4.15 with commit c17401a1dd21 and fixed in 4.19.211 with commit 60ad4cde0ad2
	Issue introduced in 4.15 with commit c17401a1dd21 and fixed in 5.4.153 with commit 17063cac4088
	Issue introduced in 4.15 with commit c17401a1dd21 and fixed in 5.10.73 with commit 97aeed72af4f
	Issue introduced in 4.15 with commit c17401a1dd21 and fixed in 5.14.12 with commit 75099439209d
	Issue introduced in 4.15 with commit c17401a1dd21 and fixed in 5.15 with commit 2e5a20573a92

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-2021-47424
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_main.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/60ad4cde0ad28921f9ea25b0201c774b95ffa4b4
	https://git.kernel.org/stable/c/17063cac4088b8e2fc0f633abddca5426ed58312
	https://git.kernel.org/stable/c/97aeed72af4f83ae51534f0a2473ff52f8d66236
	https://git.kernel.org/stable/c/75099439209d3cda439a1d9b00d19a50f0066fef
	https://git.kernel.org/stable/c/2e5a20573a926302b233b0c2e1077f5debc7ab2e