CVE-2024-26896: wifi: wfx: fix memory leak when starting AP

CVE-2024-26896: wifi: wfx: fix memory leak when starting AP

[Greg Kroah-Hartman]

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

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

wifi: wfx: fix memory leak when starting AP

Kmemleak reported this error:

    unreferenced object 0xd73d1180 (size 184):
      comm "wpa_supplicant", pid 1559, jiffies 13006305 (age 964.245s)
      hex dump (first 32 bytes):
        00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        00 00 00 00 00 00 00 00 1e 00 01 00 00 00 00 00  ................
      backtrace:
        [<5ca11420>] kmem_cache_alloc+0x20c/0x5ac
        [<127bdd74>] __alloc_skb+0x144/0x170
        [<fb8a5e38>] __netdev_alloc_skb+0x50/0x180
        [<0f9fa1d5>] __ieee80211_beacon_get+0x290/0x4d4 [mac80211]
        [<7accd02d>] ieee80211_beacon_get_tim+0x54/0x18c [mac80211]
        [<41e25cc3>] wfx_start_ap+0xc8/0x234 [wfx]
        [<93a70356>] ieee80211_start_ap+0x404/0x6b4 [mac80211]
        [<a4a661cd>] nl80211_start_ap+0x76c/0x9e0 [cfg80211]
        [<47bd8b68>] genl_rcv_msg+0x198/0x378
        [<453ef796>] netlink_rcv_skb+0xd0/0x130
        [<6b7c977a>] genl_rcv+0x34/0x44
        [<66b2d04d>] netlink_unicast+0x1b4/0x258
        [<f965b9b6>] netlink_sendmsg+0x1e8/0x428
        [<aadb8231>] ____sys_sendmsg+0x1e0/0x274
        [<d2b5212d>] ___sys_sendmsg+0x80/0xb4
        [<69954f45>] __sys_sendmsg+0x64/0xa8
    unreferenced object 0xce087000 (size 1024):
      comm "wpa_supplicant", pid 1559, jiffies 13006305 (age 964.246s)
      hex dump (first 32 bytes):
        00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        10 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............
      backtrace:
        [<9a993714>] __kmalloc_track_caller+0x230/0x600
        [<f83ea192>] kmalloc_reserve.constprop.0+0x30/0x74
        [<a2c61343>] __alloc_skb+0xa0/0x170
        [<fb8a5e38>] __netdev_alloc_skb+0x50/0x180
        [<0f9fa1d5>] __ieee80211_beacon_get+0x290/0x4d4 [mac80211]
        [<7accd02d>] ieee80211_beacon_get_tim+0x54/0x18c [mac80211]
        [<41e25cc3>] wfx_start_ap+0xc8/0x234 [wfx]
        [<93a70356>] ieee80211_start_ap+0x404/0x6b4 [mac80211]
        [<a4a661cd>] nl80211_start_ap+0x76c/0x9e0 [cfg80211]
        [<47bd8b68>] genl_rcv_msg+0x198/0x378
        [<453ef796>] netlink_rcv_skb+0xd0/0x130
        [<6b7c977a>] genl_rcv+0x34/0x44
        [<66b2d04d>] netlink_unicast+0x1b4/0x258
        [<f965b9b6>] netlink_sendmsg+0x1e8/0x428
        [<aadb8231>] ____sys_sendmsg+0x1e0/0x274
        [<d2b5212d>] ___sys_sendmsg+0x80/0xb4

However, since the kernel is build optimized, it seems the stack is not
accurate. It appears the issue is related to wfx_set_mfp_ap(). The issue
is obvious in this function: memory allocated by ieee80211_beacon_get()
is never released. Fixing this leak makes kmemleak happy.

The Linux kernel CVE team has assigned CVE-2024-26896 to this issue.


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

	Issue introduced in 5.10 with commit 268bceec1684 and fixed in 6.1.83 with commit a1f57a0127b8
	Issue introduced in 5.10 with commit 268bceec1684 and fixed in 6.6.23 with commit 3a71ec74e5e3
	Issue introduced in 5.10 with commit 268bceec1684 and fixed in 6.7.11 with commit 12f00a367b2b
	Issue introduced in 5.10 with commit 268bceec1684 and fixed in 6.8.2 with commit dadbb5d29d6c
	Issue introduced in 5.10 with commit 268bceec1684 and fixed in 6.9-rc1 with commit b8cfb7c819dd

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-2024-26896
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/silabs/wfx/sta.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/a1f57a0127b89a6b6620514564aa7eaec16d9af3
	https://git.kernel.org/stable/c/3a71ec74e5e3478d202a1874f085ca3ef40be49b
	https://git.kernel.org/stable/c/12f00a367b2b62756e0396f14b54c2c15524e1c3
	https://git.kernel.org/stable/c/dadbb5d29d6c5f571a50272fce8c1505a9559487
	https://git.kernel.org/stable/c/b8cfb7c819dd39965136a66fe3a7fde688d976fc