2021-04-01 19:30:38

by Larry Finger

[permalink] [raw]
Subject: [PATCH] rtw88: Fix array overrun in rtw_get_tx_power_params()

From: Ping-Ke Shih <[email protected]>

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")

Fixes: fa6dfe6bff24 ("rtw88: resolve order of tx power setting routines")
Reported-by: Богдан Пилипенко <[email protected]>
Signed-off-by: Larry Finger <[email protected]>
Signed-off-by: Ping-Ke Shih <[email protected]>
Cc: Stable <[email protected]>
---
drivers/net/wireless/realtek/rtw88/phy.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/phy.c b/drivers/net/wireless/realtek/rtw88/phy.c
index e114ddecac09..0b3da5bef703 100644
--- a/drivers/net/wireless/realtek/rtw88/phy.c
+++ b/drivers/net/wireless/realtek/rtw88/phy.c
@@ -1584,7 +1584,7 @@ void rtw_phy_load_tables(struct rtw_dev *rtwdev)
}
EXPORT_SYMBOL(rtw_phy_load_tables);

-static u8 rtw_get_channel_group(u8 channel)
+static u8 rtw_get_channel_group(u8 channel, u8 rate)
{
switch (channel) {
default:
@@ -1628,6 +1628,7 @@ static u8 rtw_get_channel_group(u8 channel)
case 106:
return 4;
case 14:
+ return rate <= DESC_RATE11M ? 5 : 4;
case 108:
case 110:
case 112:
@@ -1879,7 +1880,7 @@ void rtw_get_tx_power_params(struct rtw_dev *rtwdev, u8 path, u8 rate, u8 bw,
s8 *remnant = &pwr_param->pwr_remnant;

pwr_idx = &rtwdev->efuse.txpwr_idx_table[path];
- group = rtw_get_channel_group(ch);
+ group = rtw_get_channel_group(ch, rate);

/* base power index for 2.4G/5G */
if (IS_CH_2G_BAND(ch)) {
--
2.30.2


2021-04-18 06:35:59

by Kalle Valo

[permalink] [raw]
Subject: Re: rtw88: Fix array overrun in rtw_get_tx_power_params()

Larry Finger <[email protected]> wrote:

> From: Ping-Ke Shih <[email protected]>
>
> 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")
>
> Fixes: fa6dfe6bff24 ("rtw88: resolve order of tx power setting routines")
> Reported-by: Богдан Пилипенко <[email protected]>
> Signed-off-by: Larry Finger <[email protected]>
> Signed-off-by: Ping-Ke Shih <[email protected]>
> Cc: Stable <[email protected]>

Patch applied to wireless-drivers-next.git, thanks.

2ff25985ea9c rtw88: Fix array overrun in rtw_get_tx_power_params()

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches