CVE-2026-98105: net: ethernet: oa_tc6: Improve the error recovery

CVE-2026-98105: net: ethernet: oa_tc6: Improve the error recovery

[Greg Kroah-Hartman]

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

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

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

net: ethernet: oa_tc6: Improve the error recovery

When oversubscribed traffic causes lot of buffer overflow errors,
probably due to loss of data chunks, driver fails to find a
data chunk with end_valid bit set, before it runs out of sk buffer
space. As a result, assert is seen during skb_put.

Now, check is made if skb buffer has enough tailroom for the
incoming data before accepting. If there is no room, current
frame is abandoned and it will start looking for a data chunk
with start_valid bit, that is a new frame.

SK buffer allocation error is considered as recoverable error.

rx_buf_overflow flag is too specific and no longer the only
condition this flag is used for. Therefore it is renamed as
wait_until_start_valid. This is more appropriate as this flag
is used to look for the next data chunk with SV bit set, after
failures like buffer overflow, buffer allocation failure, skb pointer
validity besides buffer overflow error.

Not writing to status0 if it reads 0.

The Linux kernel CVE team has assigned CVE-2026-98105 to this issue.


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

	Issue introduced in 6.12 with commit d70a0d8f2f2d1b9bb6e3e9dfed25ae3ca3303770 and fixed in 6.12.111 with commit d33003e752f25c385f2cf21964123582a44f6818
	Issue introduced in 6.12 with commit d70a0d8f2f2d1b9bb6e3e9dfed25ae3ca3303770 and fixed in 6.18.53 with commit 9d3f6e714d5f8b728837f31bbe865b64cfd3216a
	Issue introduced in 6.12 with commit d70a0d8f2f2d1b9bb6e3e9dfed25ae3ca3303770 and fixed in 7.2.7 with commit b89770d493749d7c3b8649996e1089719b4eff8d
	Issue introduced in 6.12 with commit d70a0d8f2f2d1b9bb6e3e9dfed25ae3ca3303770 and fixed in 7.3-rc2 with commit 172c974113bffe5723b80b1acac17593bb50513c

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-2026-98105
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/oa_tc6.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/d33003e752f25c385f2cf21964123582a44f6818
	https://git.kernel.org/stable/c/9d3f6e714d5f8b728837f31bbe865b64cfd3216a
	https://git.kernel.org/stable/c/b89770d493749d7c3b8649996e1089719b4eff8d
	https://git.kernel.org/stable/c/172c974113bffe5723b80b1acac17593bb50513c