Subject: CVE-2021-47453: ice: Avoid crash from unnecessary IDA free

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

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

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

ice: Avoid crash from unnecessary IDA free

In the remove path, there is an attempt to free the aux_idx IDA whether
it was allocated or not.  This can potentially cause a crash when
unloading the driver on systems that do not initialize support for RDMA.
But, this free cannot be gated by the status bit for RDMA, since it is
allocated if the driver detects support for RDMA at probe time, but the
driver can enter into a state where RDMA is not supported after the IDA
has been allocated at probe time and this would lead to a memory leak.

Initialize aux_idx to an invalid value and check for a valid value when
unloading to determine if an IDA free is necessary.

The Linux kernel CVE team has assigned CVE-2021-47453 to this issue.

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

	Issue introduced in 5.14 with commit d25a0fc41c1f and fixed in 5.14.15 with commit 777682e59840
	Issue introduced in 5.14 with commit d25a0fc41c1f and fixed in 5.15 with commit 73e30a62b19b

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-2021-47453
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_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/777682e59840e24e6c5672197e6ffbcf4bff823b
	https://git.kernel.org/stable/c/73e30a62b19b9fbb4e6a3465c59da186630d5f2e