Subject: CVE-2024-38616: wifi: carl9170: re-fix fortified-memset warning

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

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

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

wifi: carl9170: re-fix fortified-memset warning

The carl9170_tx_release() function sometimes triggers a fortified-memset
warning in my randconfig builds:

In file included from include/linux/string.h:254,
                 from drivers/net/wireless/ath/carl9170/tx.c:40:
In function 'fortify_memset_chk',
    inlined from 'carl9170_tx_release' at drivers/net/wireless/ath/carl9170/tx.c:283:2,
    inlined from 'kref_put' at include/linux/kref.h:65:3,
    inlined from 'carl9170_tx_put_skb' at drivers/net/wireless/ath/carl9170/tx.c:342:9:
include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
  493 |                         __write_overflow_field(p_size_field, size);

Kees previously tried to avoid this by using memset_after(), but it seems
this does not fully address the problem. I noticed that the memset_after()
here is done on a different part of the union (status) than the original
cast was from (rate_driver_data), which may confuse the compiler.

Unfortunately, the memset_after() trick does not work on driver_rates[]
because that is part of an anonymous struct, and I could not get
struct_group() to do this either. Using two separate memset() calls
on the two members does address the warning though.

The Linux kernel CVE team has assigned CVE-2024-38616 to this issue.

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

	Issue introduced in 5.17 with commit fb5f6a0e8063 and fixed in 6.1.93 with commit 13857683126e
	Issue introduced in 5.17 with commit fb5f6a0e8063 and fixed in 6.6.33 with commit 875864670982
	Issue introduced in 5.17 with commit fb5f6a0e8063 and fixed in 6.8.12 with commit 0c38c9c460bb
	Issue introduced in 5.17 with commit fb5f6a0e8063 and fixed in 6.9.3 with commit 042a39bb8e08
	Issue introduced in 5.17 with commit fb5f6a0e8063 and fixed in 6.10 with commit 066afafc10c9

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-2024-38616
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/wireless/ath/carl9170/tx.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/13857683126e8a6492af73c74d702835f7a2175b
	https://git.kernel.org/stable/c/87586467098281f04fa93e59fe3a516b954bddc4
	https://git.kernel.org/stable/c/0c38c9c460bb8ce8d6f6cf316e0d71a70983ec83
	https://git.kernel.org/stable/c/042a39bb8e0812466327a5102606e88a5a4f8c02
	https://git.kernel.org/stable/c/066afafc10c9476ee36c47c9062527a17e763901