From 959c13da6c36167ce1016d400a6104d2367f686e Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Thu, 30 Apr 2026 12:07:40 -0400 Subject: [PATCH] wifi: rtw88: check for PCI upstream bridge existence [ Upstream commit eb101d2abdcccb514ca4fccd3b278dd8267374f6 ] pci_upstream_bridge() returns NULL if the device is on a root bus. If 8821CE is installed in the system with such a PCI topology, the probing routine will crash. This has probably been unnoticed as 8821CE is mostly supplied in laptops where there is a PCI-to-PCI bridge located upstream from the device. However the card might be installed on a system with different configuration. Check if the bridge does exist for the specific workaround to be applied. Found by Linux Verification Center (linuxtesting.org) with Svace static analysis tool. Fixes: 24f5e38a13b5 ("rtw88: Disable PCIe ASPM while doing NAPI poll on 8821CE") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Acked-by: Ping-Ke Shih Signed-off-by: Ping-Ke Shih Link: https://patch.msgid.link/20260220094730.49791-1-pchelkin@ispras.ru Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/realtek/rtw88/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index 0d1b1dfab8a2..fa302d5e7839 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -1766,7 +1766,8 @@ int rtw_pci_probe(struct pci_dev *pdev, } /* Disable PCIe ASPM L1 while doing NAPI poll for 8821CE */ - if (rtwdev->chip->id == RTW_CHIP_TYPE_8821C && bridge->vendor == PCI_VENDOR_ID_INTEL) + if (rtwdev->chip->id == RTW_CHIP_TYPE_8821C && + bridge && bridge->vendor == PCI_VENDOR_ID_INTEL) rtwpci->rx_no_aspm = true; rtw_pci_phy_cfg(rtwdev);