From: Paweł Lenkow pawel.lenkow@camlingroup.com
[ Upstream commit be92292b90bfdc31f332c962882b6d3ea0285fdf ]
During our testing of WFM200 module over SDIO on i.MX6Q-based platform, we discovered a memory corruption on the system, tracing back to the wfx driver. Using kfence, it was possible to trace it back to the root cause, which is hw->max_rates set to 8 in wfx_init_common, while the maximum defined by IEEE80211_TX_TABLE_SIZE is 4.
This causes array out-of-bounds writes during updates of the rate table, as seen below:
BUG: KFENCE: memory corruption in kfree_rcu_work+0x320/0x36c
Corrupted memory at 0xe0a4ffe0 [ 0x03 0x03 0x03 0x03 0x01 0x00 0x00 0x02 0x02 0x02 0x09 0x00 0x21 0xbb 0xbb 0xbb ] (in kfence-#81): kfree_rcu_work+0x320/0x36c process_one_work+0x3ec/0x920 worker_thread+0x60/0x7a4 kthread+0x174/0x1b4 ret_from_fork+0x14/0x2c 0x0
kfence-#81: 0xe0a4ffc0-0xe0a4ffdf, size=32, cache=kmalloc-64
allocated by task 297 on cpu 0 at 631.039555s: minstrel_ht_update_rates+0x38/0x2b0 [mac80211] rate_control_tx_status+0xb4/0x148 [mac80211] ieee80211_tx_status_ext+0x364/0x1030 [mac80211] ieee80211_tx_status+0xe0/0x118 [mac80211] ieee80211_tasklet_handler+0xb0/0xe0 [mac80211] tasklet_action_common.constprop.0+0x11c/0x148 __do_softirq+0x1a4/0x61c irq_exit+0xcc/0x104 call_with_stack+0x18/0x20 __irq_svc+0x80/0xb0 wq_worker_sleeping+0x10/0x100 wq_worker_sleeping+0x10/0x100 schedule+0x50/0xe0 schedule_timeout+0x2e0/0x474 wait_for_completion+0xdc/0x1ec mmc_wait_for_req_done+0xc4/0xf8 mmc_io_rw_extended+0x3b4/0x4ec sdio_io_rw_ext_helper+0x290/0x384 sdio_memcpy_toio+0x30/0x38 wfx_sdio_copy_to_io+0x88/0x108 [wfx] wfx_data_write+0x88/0x1f0 [wfx] bh_work+0x1c8/0xcc0 [wfx] process_one_work+0x3ec/0x920 worker_thread+0x60/0x7a4 kthread+0x174/0x1b4 ret_from_fork+0x14/0x2c 0x0
After discussion on the wireless mailing list it was clarified that the issue has been introduced by: commit ee0e16ab756a ("mac80211: minstrel_ht: fill all requested rates") and fix shall be in minstrel_ht_update_rates in rc80211_minstrel_ht.c.
Fixes: ee0e16ab756a ("mac80211: minstrel_ht: fill all requested rates") Link: https://lore.kernel.org/all/12e5adcd-8aed-f0f7-70cc-4fb7b656b829@camlingroup... Link: https://lore.kernel.org/linux-wireless/20220915131445.30600-1-lech.perczak@c... Cc: Jérôme Pouiller jerome.pouiller@silabs.com Cc: Johannes Berg johannes@sipsolutions.net Cc: Peter Seiderer ps.report@gmx.net Cc: Kalle Valo kvalo@kernel.org Cc: Krzysztof Drobiński krzysztof.drobinski@camlingroup.com, Signed-off-by: Paweł Lenkow pawel.lenkow@camlingroup.com Signed-off-by: Lech Perczak lech.perczak@camlingroup.com Reviewed-by: Peter Seiderer ps.report@gmx.net Reviewed-by: Jérôme Pouiller jerome.pouiller@silabs.com Acked-by: Felix Fietkau nbd@nbd.name Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/rc80211_minstrel_ht.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 5f27e6746762..788a82f9c74d 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -10,6 +10,7 @@ #include <linux/random.h> #include <linux/moduleparam.h> #include <linux/ieee80211.h> +#include <linux/minmax.h> #include <net/mac80211.h> #include "rate.h" #include "sta_info.h" @@ -1550,6 +1551,7 @@ minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) { struct ieee80211_sta_rates *rates; int i = 0; + int max_rates = min_t(int, mp->hw->max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
rates = kzalloc(sizeof(*rates), GFP_ATOMIC); if (!rates) @@ -1559,10 +1561,10 @@ minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
/* Fill up remaining, keep one entry for max_probe_rate */ - for (; i < (mp->hw->max_rates - 1); i++) + for (; i < (max_rates - 1); i++) minstrel_ht_set_rate(mp, mi, rates, i, mi->max_tp_rate[i]);
- if (i < mp->hw->max_rates) + if (i < max_rates) minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
if (i < IEEE80211_TX_RATE_TABLE_SIZE)