[PATCH 6.19 37/49] wifi: rtw88: Fix alignment fault in rtw_core_enable_beacon()

Greg Kroah-Hartman
2026-02-13T13:51:01Z

From: Bitterblue Smith <rtl8821cerfe2@gmail.com>

commit 0177aa828d966117ea30a44f2e1890fdb356118e upstream.

rtw_core_enable_beacon() reads 4 bytes from an address that is not a
multiple of 4. This results in a crash on some systems.

Do 1 byte reads/writes instead.

Unable to handle kernel paging request at virtual address ffff8000827e0522
Mem abort info:
ESR = 0x0000000096000021
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x21: alignment fault
Data abort info:
ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000005492000
[ffff8000827e0522] pgd=0000000000000000, p4d=10000001021d9403, pud=10000001021da403, pmd=100000011061c403, pte=00780000f3200f13
Internal error: Oops: 0000000096000021 [#1] SMP
Modules linked in: [...] rtw88_8822ce rtw88_8822c rtw88_pci rtw88_core [...]
CPU: 0 UID: 0 PID: 73 Comm: kworker/u32:2 Tainted: G W 6.17.9 #1-NixOS VOLUNTARY
Tainted: [W]=WARN
Hardware name: FriendlyElec NanoPC-T6 LTS (DT)
Workqueue: phy0 rtw_c2h_work [rtw88_core]
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : rtw_pci_read32+0x18/0x40 [rtw88_pci]
lr : rtw_core_enable_beacon+0xe0/0x148 [rtw88_core]
sp : ffff800080cc3ca0
x29: ffff800080cc3ca0 x28: ffff0001031fc240 x27: ffff000102100828
x26: ffffd2cb7c9b4088 x25: ffff0001031fc2c0 x24: ffff000112fdef00
x23: ffff000112fdef18 x22: ffff000111c29970 x21: 0000000000000001
x20: 0000000000000001 x19: ffff000111c22040 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : ffffd2cb6507c090
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000007f10 x1 : 0000000000000522 x0 : ffff8000827e0522
Call trace:
rtw_pci_read32+0x18/0x40 [rtw88_pci] (P)
rtw_hw_scan_chan_switch+0x124/0x1a8 [rtw88_core]
rtw_fw_c2h_cmd_handle+0x254/0x290 [rtw88_core]
rtw_c2h_work+0x50/0x98 [rtw88_core]
process_one_work+0x178/0x3f8
worker_thread+0x208/0x418
kthread+0x120/0x220
ret_from_fork+0x10/0x20
Code: d28fe202 8b020000 f9524400 8b214000 (b9400000)
---[ end trace 0000000000000000 ]---

Fixes: ad6741b1e044 ("wifi: rtw88: Stop high queue during scan")
Cc: stable@vger.kernel.org
Closes: https://github.com/lwfinger/rtw88/issues/418
Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/6345300d-8c93-464c-9b05-d0d9af3c97ad@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/realtek/rtw88/main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -2444,10 +2444,10 @@ void rtw_core_enable_beacon(struct rtw_d

if (enable) {
rtw_write32_set(rtwdev, REG_BCN_CTRL, BIT_EN_BCN_FUNCTION);
- rtw_write32_clr(rtwdev, REG_TXPAUSE, BIT_HIGH_QUEUE);
+ rtw_write8_clr(rtwdev, REG_TXPAUSE, BIT_HIGH_QUEUE);
} else {
rtw_write32_clr(rtwdev, REG_BCN_CTRL, BIT_EN_BCN_FUNCTION);
- rtw_write32_set(rtwdev, REG_TXPAUSE, BIT_HIGH_QUEUE);
+ rtw_write8_set(rtwdev, REG_TXPAUSE, BIT_HIGH_QUEUE);
}
}