2022-11-08 15:21:19

by Lorenzo Bianconi

Subject: [PATCH v2 wireless] wifi: mac8021: fix possible oob access in ieee80211_get_rate_duration

Fix possible out-of-bound access in ieee80211_get_rate_duration routine
as reported by the following UBSAN report:

UBSAN: array-index-out-of-bounds in net/mac80211/airtime.c:455:47
index 15 is out of range for type 'u16 [12]'
CPU: 2 PID: 217 Comm: kworker/u32:10 Not tainted 6.1.0-060100rc3-generic
Hardware name: Acer Aspire TC-281/Aspire TC-281, BIOS R01-A2 07/18/2017
Workqueue: mt76 mt76u_tx_status_data [mt76_usb]
Call Trace:
<TASK>
show_stack+0x4e/0x61
dump_stack_lvl+0x4a/0x6f
dump_stack+0x10/0x18
ubsan_epilogue+0x9/0x43
__ubsan_handle_out_of_bounds.cold+0x42/0x47
ieee80211_get_rate_duration.constprop.0+0x22f/0x2a0 [mac80211]
? ieee80211_tx_status_ext+0x32e/0x640 [mac80211]
ieee80211_calc_rx_airtime+0xda/0x120 [mac80211]
ieee80211_calc_tx_airtime+0xb4/0x100 [mac80211]
mt76x02_send_tx_status+0x266/0x480 [mt76x02_lib]
mt76x02_tx_status_data+0x52/0x80 [mt76x02_lib]
mt76u_tx_status_data+0x67/0xd0 [mt76_usb]
process_one_work+0x225/0x400
worker_thread+0x50/0x3e0
? process_one_work+0x400/0x400
kthread+0xe9/0x110
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x22/0x30

Fixes: db3e1c40cf2f ("mac80211: Import airtime calculation code from mt76")
Signed-off-by: Lorenzo Bianconi <[email protected]>
---
Changes since v1:
- drop WARN_ON_ONCE
---
net/mac80211/airtime.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/mac80211/airtime.c b/net/mac80211/airtime.c
index 2e66598fac79..e8ebd343e2bf 100644
--- a/net/mac80211/airtime.c
+++ b/net/mac80211/airtime.c
@@ -452,6 +452,9 @@ static u32 ieee80211_get_rate_duration(struct ieee80211_hw *hw,
(status->encoding == RX_ENC_HE && streams > 8)))
return 0;

+ if (idx >= MCS_GROUP_RATES)
+ return 0;
+
duration = airtime_mcs_groups[group].duration[idx];
duration <<= airtime_mcs_groups[group].shift;
*overhead = 36 + (streams << 2);
--
2.38.1

2022-11-08 15:44:01

by Toke Høiland-Jørgensen

Subject: Re: [PATCH v2 wireless] wifi: mac8021: fix possible oob access in ieee80211_get_rate_duration

Lorenzo Bianconi <[email protected]> writes:

> Fix possible out-of-bound access in ieee80211_get_rate_duration routine
> as reported by the following UBSAN report:
>
> UBSAN: array-index-out-of-bounds in net/mac80211/airtime.c:455:47
> index 15 is out of range for type 'u16 [12]'
> CPU: 2 PID: 217 Comm: kworker/u32:10 Not tainted 6.1.0-060100rc3-generic
> Hardware name: Acer Aspire TC-281/Aspire TC-281, BIOS R01-A2 07/18/2017
> Workqueue: mt76 mt76u_tx_status_data [mt76_usb]
> Call Trace:
> <TASK>
> show_stack+0x4e/0x61
> dump_stack_lvl+0x4a/0x6f
> dump_stack+0x10/0x18
> ubsan_epilogue+0x9/0x43
> __ubsan_handle_out_of_bounds.cold+0x42/0x47
> ieee80211_get_rate_duration.constprop.0+0x22f/0x2a0 [mac80211]
> ? ieee80211_tx_status_ext+0x32e/0x640 [mac80211]
> ieee80211_calc_rx_airtime+0xda/0x120 [mac80211]
> ieee80211_calc_tx_airtime+0xb4/0x100 [mac80211]
> mt76x02_send_tx_status+0x266/0x480 [mt76x02_lib]
> mt76x02_tx_status_data+0x52/0x80 [mt76x02_lib]
> mt76u_tx_status_data+0x67/0xd0 [mt76_usb]
> process_one_work+0x225/0x400
> worker_thread+0x50/0x3e0
> ? process_one_work+0x400/0x400
> kthread+0xe9/0x110
> ? kthread_complete_and_exit+0x20/0x20
> ret_from_fork+0x22/0x30
>
> Fixes: db3e1c40cf2f ("mac80211: Import airtime calculation code from mt76")
> Signed-off-by: Lorenzo Bianconi <[email protected]>

Acked-by: Toke Høiland-Jørgensen <[email protected]>