Subject: CVE-2024-50042: ice: Fix increasing MSI-X on VF

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

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

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

ice: Fix increasing MSI-X on VF

Increasing MSI-X value on a VF leads to invalid memory operations. This
is caused by not reallocating some arrays.

Reproducer:
  modprobe ice
  echo 0 > /sys/bus/pci/devices/$PF_PCI/sriov_drivers_autoprobe
  echo 1 > /sys/bus/pci/devices/$PF_PCI/sriov_numvfs
  echo 17 > /sys/bus/pci/devices/$VF0_PCI/sriov_vf_msix_count

Default MSI-X is 16, so 17 and above triggers this issue.

KASAN reports:

  BUG: KASAN: slab-out-of-bounds in ice_vsi_alloc_ring_stats+0x38d/0x4b0 [ice]
  Read of size 8 at addr ffff8888b937d180 by task bash/28433
  (...)

  Call Trace:
   (...)
   ? ice_vsi_alloc_ring_stats+0x38d/0x4b0 [ice]
   kasan_report+0xed/0x120
   ? ice_vsi_alloc_ring_stats+0x38d/0x4b0 [ice]
   ice_vsi_alloc_ring_stats+0x38d/0x4b0 [ice]
   ice_vsi_cfg_def+0x3360/0x4770 [ice]
   ? mutex_unlock+0x83/0xd0
   ? __pfx_ice_vsi_cfg_def+0x10/0x10 [ice]
   ? __pfx_ice_remove_vsi_lkup_fltr+0x10/0x10 [ice]
   ice_vsi_cfg+0x7f/0x3b0 [ice]
   ice_vf_reconfig_vsi+0x114/0x210 [ice]
   ice_sriov_set_msix_vec_count+0x3d0/0x960 [ice]
   sriov_vf_msix_count_store+0x21c/0x300
   (...)

  Allocated by task 28201:
   (...)
   ice_vsi_cfg_def+0x1c8e/0x4770 [ice]
   ice_vsi_cfg+0x7f/0x3b0 [ice]
   ice_vsi_setup+0x179/0xa30 [ice]
   ice_sriov_configure+0xcaa/0x1520 [ice]
   sriov_numvfs_store+0x212/0x390
   (...)

To fix it, use ice_vsi_rebuild() instead of ice_vf_reconfig_vsi(). This
causes the required arrays to be reallocated taking the new queue count
into account (ice_vsi_realloc_stat_arrays()). Set req_txq and req_rxq
before ice_vsi_rebuild(), so that realloc uses the newly set queue
count.

Additionally, ice_vsi_rebuild() does not remove VSI filters
(ice_fltr_remove_all()), so ice_vf_init_host_cfg() is no longer
necessary.

The Linux kernel CVE team has assigned CVE-2024-50042 to this issue.

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

	Issue introduced in 6.8 with commit 2a2cb4c6c181 and fixed in 6.11.4 with commit cbda61979294
	Issue introduced in 6.8 with commit 2a2cb4c6c181 and fixed in 6.12-rc3 with commit bce9af1b030b
	Issue introduced in 6.7.10 with commit 8910b1cef190

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-2024-50042
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/ice/ice_sriov.c
	drivers/net/ethernet/intel/ice/ice_vf_lib.c
	drivers/net/ethernet/intel/ice/ice_vf_lib_private.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/cbda6197929418fabf0e45ecf9b7a76360944c70
	https://git.kernel.org/stable/c/bce9af1b030bf59d51bbabf909a3ef164787e44e