Subject: CVE-2021-47065: rtw88: Fix array overrun in rtw_get_tx_power_params()

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

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

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

rtw88: Fix array overrun in rtw_get_tx_power_params()

Using a kernel with the Undefined Behaviour Sanity Checker (UBSAN) enabled, the
following array overrun is logged:

================================================================================
UBSAN: array-index-out-of-bounds in /home/finger/wireless-drivers-next/drivers/net/wireless/realtek/rtw88/phy.c:1789:34
index 5 is out of range for type 'u8 [5]'
CPU: 2 PID: 84 Comm: kworker/u16:3 Tainted: G           O      5.12.0-rc5-00086-gd88bba47038e-dirty #651
Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.50   09/29/2014
Workqueue: phy0 ieee80211_scan_work [mac80211]
Call Trace:
 dump_stack+0x64/0x7c
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_out_of_bounds.cold+0x43/0x48
 rtw_get_tx_power_params+0x83a/drivers/net/wireless/realtek/rtw88/0xad0 [rtw_core]
 ? rtw_pci_read16+0x20/0x20 [rtw_pci]
 ? check_hw_ready+0x50/0x90 [rtw_core]
 rtw_phy_get_tx_power_index+0x4d/0xd0 [rtw_core]
 rtw_phy_set_tx_power_level+0xee/0x1b0 [rtw_core]
 rtw_set_channel+0xab/0x110 [rtw_core]
 rtw_ops_config+0x87/0xc0 [rtw_core]
 ieee80211_hw_config+0x9d/0x130 [mac80211]
 ieee80211_scan_state_set_channel+0x81/0x170 [mac80211]
 ieee80211_scan_work+0x19f/0x2a0 [mac80211]
 process_one_work+0x1dd/0x3a0
 worker_thread+0x49/0x330
 ? rescuer_thread+0x3a0/0x3a0
 kthread+0x134/0x150
 ? kthread_create_worker_on_cpu+0x70/0x70
 ret_from_fork+0x22/0x30
================================================================================

The statement where an array is being overrun is shown in the following snippet:

	if (rate <= DESC_RATE11M)
		tx_power = pwr_idx_2g->cck_base[group];
	else
====>		tx_power = pwr_idx_2g->bw40_base[group];

The associated arrays are defined in main.h as follows:

struct rtw_2g_txpwr_idx {
	u8 cck_base[6];
	u8 bw40_base[5];
	struct rtw_2g_1s_pwr_idx_diff ht_1s_diff;
	struct rtw_2g_ns_pwr_idx_diff ht_2s_diff;
	struct rtw_2g_ns_pwr_idx_diff ht_3s_diff;
	struct rtw_2g_ns_pwr_idx_diff ht_4s_diff;
};

The problem arises because the value of group is 5 for channel 14. The trivial
increase in the dimension of bw40_base fails as this struct must match the layout of
efuse. The fix is to add the rate as an argument to rtw_get_channel_group() and set
the group for channel 14 to 4 if rate <= DESC_RATE11M.

This patch fixes commit fa6dfe6bff24 ("rtw88: resolve order of tx power setting routines")

The Linux kernel CVE team has assigned CVE-2021-47065 to this issue.

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

	Issue introduced in 5.3 with commit fa6dfe6bff24 and fixed in 5.4.119 with commit 6b5aa0cf321c
	Issue introduced in 5.3 with commit fa6dfe6bff24 and fixed in 5.10.37 with commit 95fb153c6027
	Issue introduced in 5.3 with commit fa6dfe6bff24 and fixed in 5.11.21 with commit 5f3dbced8eaa
	Issue introduced in 5.3 with commit fa6dfe6bff24 and fixed in 5.12.4 with commit 9cd09722e18a
	Issue introduced in 5.3 with commit fa6dfe6bff24 and fixed in 5.13 with commit 2ff25985ea9c

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-2021-47065
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/realtek/rtw88/phy.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/6b5aa0cf321c25f41e09a61c83ee4dc7ab9549cb
	https://git.kernel.org/stable/c/95fb153c6027924cda3422120169d1890737f3a0
	https://git.kernel.org/stable/c/5f3dbced8eaa5c9ed7d6943f3fea99f235a6516a
	https://git.kernel.org/stable/c/9cd09722e18a08b6a3d68b8bccfac39ddc22434c
	https://git.kernel.org/stable/c/2ff25985ea9ccc6c9af2c77b0b49045adcc62e0e