From: Ming Yen Hsieh mingyen.hsieh@mediatek.com

Address a kernel panic caused by a null pointer dereference in the `mt792x_rx_get_wcid` function. The issue arises because the `deflink` structure is not properly initialized with the `sta` context. This patch ensures that the `deflink` structure is correctly linked to the `sta` context, preventing the null pointer dereference.

BUG: kernel NULL pointer dereference, address: 0000000000000400 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 UID: 0 PID: 470 Comm: mt76-usb-rx phy Not tainted 6.12.13-gentoo-dist #1 Hardware name: /AMD HUDSON-M1, BIOS 4.6.4 11/15/2011 RIP: 0010:mt792x_rx_get_wcid+0x48/0x140 [mt792x_lib] RSP: 0018:ffffa147c055fd98 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff8e9ecb652000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8e9ecb652000 RBP: 0000000000000685 R08: ffff8e9ec6570000 R09: 0000000000000000 R10: ffff8e9ecd2ca000 R11: ffff8e9f22a217c0 R12: 0000000038010119 R13: 0000000080843801 R14: ffff8e9ec6570000 R15: ffff8e9ecb652000 FS: 0000000000000000(0000) GS:ffff8e9f22a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000400 CR3: 000000000d2ea000 CR4: 00000000000006f0 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? page_fault_oops+0x15a/0x2f0 ? search_module_extables+0x19/0x60 ? search_bpf_extables+0x5f/0x80 ? exc_page_fault+0x7e/0x180 ? asm_exc_page_fault+0x26/0x30 ? mt792x_rx_get_wcid+0x48/0x140 [mt792x_lib] mt7921_queue_rx_skb+0x1c6/0xaa0 [mt7921_common] mt76u_alloc_queues+0x784/0x810 [mt76_usb] ? __pfx___mt76_worker_fn+0x10/0x10 [mt76] __mt76_worker_fn+0x4f/0x80 [mt76] kthread+0xd2/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> ---[ end trace 0000000000000000 ]---

Reported-by: Nick Morrow usbwifi2024@gmail.com Closes: https://github.com/morrownr/USB-WiFi/issues/577 Cc: stable@vger.kernel.org Fixes: 90c10286b176 ("wifi: mt76: mt7925: Update mt792x_rx_get_wcid for per-link STA") Signed-off-by: Ming Yen Hsieh mingyen.hsieh@mediatek.com Tested-by: Salah Coronya salah.coronya@gmail.com --- v2: - Change Nick from "Tested-by" to "Reported-by". v3: - Rewrite the commit msg in the imperative mood. - Remove the boot time for code trace. --- drivers/net/wireless/mediatek/mt76/mt7921/main.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/main.c b/drivers/net/wireless/mediatek/mt76/mt7921/main.c index 13e58c328aff..78b77a54d195 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c @@ -811,6 +811,7 @@ int mt7921_mac_sta_add(struct mt76_dev *mdev, struct ieee80211_vif *vif, msta->deflink.wcid.phy_idx = mvif->bss_conf.mt76.band_idx; msta->deflink.wcid.tx_info |= MT_WCID_TX_INFO_SET; msta->deflink.last_txs = jiffies; + msta->deflink.sta = msta;

ret = mt76_connac_pm_wake(&dev->mphy, &dev->pm); if (ret)