[ 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>
[ Upstream commit 39ab8fff623053a50951b659e5f6b72343d7d78c ]
Commit 205c50306acf ("wifi: wilc1000: fix RCU usage in connect path")
made sure that the IEs data was manipulated under the relevant RCU section.
Unfortunately, while doing so, the commit brought a faulty implicit cast
from int to u8 on the ies_len variable, making the parsing fail to be
performed correctly if the IEs block is larger than 255 bytes. This failure
can be observed with Access Points appending a lot of IEs TLVs in their
beacon frames (reproduced with a Pixel phone acting as an Access Point,
which brough 273 bytes of IE data in my testing environment).
Fix IEs parsing by removing this undesired implicit cast.
Fixes: 205c50306acf ("wifi: wilc1000: fix RCU usage in connect path")
Signed-off-by: Jozef Hopko <jozef.hopko@altana.com>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Acked-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20240701-wilc_fix_ies_data-v1-1-7486cbacf98a@bootlin.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 205c50306acf58a335eb19fa84e40140f4fe814f ]
With lockdep enabled, calls to the connect function from cfg802.11 layer
lead to the following warning:
=============================
WARNING: suspicious RCU usage
6.7.0-rc1-wt+ #333 Not tainted
-----------------------------
drivers/net/wireless/microchip/wilc1000/hif.c:386
suspicious rcu_dereference_check() usage!
[...]
stack backtrace:
CPU: 0 PID: 100 Comm: wpa_supplicant Not tainted 6.7.0-rc1-wt+ #333
Hardware name: Atmel SAMA5
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x34/0x48
dump_stack_lvl from wilc_parse_join_bss_param+0x7dc/0x7f4
wilc_parse_join_bss_param from connect+0x2c4/0x648
connect from cfg80211_connect+0x30c/0xb74
cfg80211_connect from nl80211_connect+0x860/0xa94
nl80211_connect from genl_rcv_msg+0x3fc/0x59c
genl_rcv_msg from netlink_rcv_skb+0xd0/0x1f8
netlink_rcv_skb from genl_rcv+0x2c/0x3c
genl_rcv from netlink_unicast+0x3b0/0x550
netlink_unicast from netlink_sendmsg+0x368/0x688
netlink_sendmsg from ____sys_sendmsg+0x190/0x430
____sys_sendmsg from ___sys_sendmsg+0x110/0x158
___sys_sendmsg from sys_sendmsg+0xe8/0x150
sys_sendmsg from ret_fast_syscall+0x0/0x1c
This warning is emitted because in the connect path, when trying to parse
target BSS parameters, we dereference a RCU pointer whithout being in RCU
critical section.
Fix RCU dereference usage by moving it to a RCU read critical section. To
avoid wrapping the whole wilc_parse_join_bss_param under the critical
section, just use the critical section to copy ies data
Fixes: c460495ee072 ("staging: wilc1000: fix incorrent type in initializer")
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240105075733.36331-3-alexis.lothore@bootlin.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
