6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jiawei Ye jiawei.ye@foxmail.com
[ Upstream commit 6d7c6ae1efb1ff68bc01d79d94fdf0388f86cdd8 ]
In the `wilc_parse_join_bss_param` function, the TSF field of the `ies` structure is accessed after the RCU read-side critical section is unlocked. According to RCU usage rules, this is illegal. Reusing this pointer can lead to unpredictable behavior, including accessing memory that has been updated or causing use-after-free issues.
This possible bug was identified using a static analysis tool developed by myself, specifically designed to detect RCU-related issues.
To address this, the TSF value is now stored in a local variable `ies_tsf` before the RCU lock is released. The `param->tsf_lo` field is then assigned using this local variable, ensuring that the TSF value is safely accessed.
Fixes: 205c50306acf ("wifi: wilc1000: fix RCU usage in connect path") Signed-off-by: Jiawei Ye jiawei.ye@foxmail.com Reviewed-by: Alexis Lothoré alexis.lothore@bootlin.com Signed-off-by: Kalle Valo kvalo@kernel.org Link: https://patch.msgid.link/tencent_466225AA599BA49627FB26F707EE17BC5407@qq.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/microchip/wilc1000/hif.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/microchip/wilc1000/hif.c b/drivers/net/wireless/microchip/wilc1000/hif.c index 13853fda3e047..420a3998d9ab2 100644 --- a/drivers/net/wireless/microchip/wilc1000/hif.c +++ b/drivers/net/wireless/microchip/wilc1000/hif.c @@ -381,6 +381,7 @@ void *wilc_parse_join_bss_param(struct cfg80211_bss *bss, struct wilc_join_bss_param *param; u8 rates_len = 0; int ies_len; + u64 ies_tsf; int ret;
param = kzalloc(sizeof(*param), GFP_KERNEL); @@ -396,6 +397,7 @@ void *wilc_parse_join_bss_param(struct cfg80211_bss *bss, return NULL; } ies_len = ies->len; + ies_tsf = ies->tsf; rcu_read_unlock();
param->beacon_period = cpu_to_le16(bss->beacon_interval); @@ -451,7 +453,7 @@ void *wilc_parse_join_bss_param(struct cfg80211_bss *bss, IEEE80211_P2P_ATTR_ABSENCE_NOTICE, (u8 *)&noa_attr, sizeof(noa_attr)); if (ret > 0) { - param->tsf_lo = cpu_to_le32(ies->tsf); + param->tsf_lo = cpu_to_le32(ies_tsf); param->noa_enabled = 1; param->idx = noa_attr.index; if (noa_attr.oppps_ctwindow & IEEE80211_P2P_OPPPS_ENABLE_BIT) {