CVE-2026-53009: ice: fix double-free of tx_buf skb

CVE-2026-53009: ice: fix double-free of tx_buf skb

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

ice: fix double-free of tx_buf skb

If ice_tso() or ice_tx_csum() fail, the error path in
ice_xmit_frame_ring() frees the skb, but the 'first' tx_buf still points
to it and is marked as valid (ICE_TX_BUF_SKB).
'next_to_use' remains unchanged, so the potential problem will
likely fix itself when the next packet is transmitted and the tx_buf
gets overwritten. But if there is no next packet and the interface is
brought down instead, ice_clean_tx_ring() -> ice_unmap_and_free_tx_buf()
will find the tx_buf and free the skb for the second time.

The fix is to reset the tx_buf type to ICE_TX_BUF_EMPTY in the error
path, so that ice_unmap_and_free_tx_buf().
Move the initialization of 'first' up, to ensure it's already valid in
case we hit the linearization error path.

The bug was spotted by AI while I had it looking for something else.
It also proposed an initial version of the patch.

I reproduced the bug and tested the fix by adding code to inject
failures, on a build with KASAN.

I looked for similar bugs in related Intel drivers and did not find any.

The Linux kernel CVE team has assigned CVE-2026-53009 to this issue.


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

	Issue introduced in 4.17 with commit d76a60ba7afb89523c88cf2ed3a044ce4180289e and fixed in 7.0.10 with commit 4c08fc2119ef0281cfa2cee007acf0a251be55f2
	Issue introduced in 4.17 with commit d76a60ba7afb89523c88cf2ed3a044ce4180289e and fixed in 7.1 with commit 1a303baa715e6b78d6a406aaf335f87ff35acfcd

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-2026-53009
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_txrx.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/4c08fc2119ef0281cfa2cee007acf0a251be55f2
	https://git.kernel.org/stable/c/1a303baa715e6b78d6a406aaf335f87ff35acfcd