Subject: CVE-2022-49026: e100: Fix possible use after free in e100_xmit_prepare

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

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

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

e100: Fix possible use after free in e100_xmit_prepare

In e100_xmit_prepare(), if we can't map the skb, then return -ENOMEM, so
e100_xmit_frame() will return NETDEV_TX_BUSY and the upper layer will
resend the skb. But the skb is already freed, which will cause UAF bug
when the upper layer resends the skb.

Remove the harmful free.

The Linux kernel CVE team has assigned CVE-2022-49026 to this issue.

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

	Issue introduced in 4.3 with commit 5e5d49422dfb and fixed in 5.10.158 with commit b775f37d9439
	Issue introduced in 4.3 with commit 5e5d49422dfb and fixed in 5.15.82 with commit 9fc27d22cdb9
	Issue introduced in 4.3 with commit 5e5d49422dfb and fixed in 6.0.12 with commit b46f6144ab89
	Issue introduced in 4.3 with commit 5e5d49422dfb and fixed in 6.1 with commit 45605c75c52c

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-2022-49026
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/e100.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/b775f37d943966f6f77dca402f5a9dedce502c25
	https://git.kernel.org/stable/c/9fc27d22cdb9b1fcd754599d216a8992fed280cd
	https://git.kernel.org/stable/c/b46f6144ab89d3d757ead940759c505091626a7d
	https://git.kernel.org/stable/c/45605c75c52c7ae7bfe902214343aabcfe5ba0ff