linux-kernel - [PATCH v4 04/12] iwlegacy: Check if pcie_capability_read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200731110240.98326-5-refactormyself@gmail.com>
Date:   Fri, 31 Jul 2020 13:02:32 +0200
From:   "Saheed O. Bolarinwa" <refactormyself@...il.com>
To:     helgaas@...nel.org, Kalle Valo <kvalo@...eaurora.org>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     "Saheed O. Bolarinwa" <refactormyself@...il.com>,
        bjorn@...gaas.com, skhan@...uxfoundation.org,
        linux-kernel-mentees@...ts.linuxfoundation.org,
        linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
        Stanislaw Gruszka <stf_xl@...pl>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH v4 04/12] iwlegacy: Check if pcie_capability_read_*() reads ~0

On failure pcie_capability_read_dword() sets it's last parameter, val
to 0. However, with Patch 12/12, it is possible that val is set to ~0
on failure. This would introduce a bug because (x & x) == (~0 & x).

Since ~0 is an invalid value here,

Add an extra check for ~0 to the if condition to ensure success.

Suggested-by: Bjorn Helgaas <bjorn@...gaas.com>
Signed-off-by: Saheed O. Bolarinwa <refactormyself@...il.com>
---
 drivers/net/wireless/intel/iwlegacy/common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
index 348c17ce72f5..659027563260 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.c
+++ b/drivers/net/wireless/intel/iwlegacy/common.c
@@ -4287,7 +4287,7 @@ il_apm_init(struct il_priv *il)
 	 */
 	if (il->cfg->set_l0s) {
 		pcie_capability_read_word(il->pci_dev, PCI_EXP_LNKCTL, &lctl);
-		if (lctl & PCI_EXP_LNKCTL_ASPM_L1) {
+		if ((lctl != (u16)~0) && (lctl & PCI_EXP_LNKCTL_ASPM_L1)) {
 			/* L1-ASPM enabled; disable(!) L0S  */
 			il_set_bit(il, CSR_GIO_REG,
 				   CSR_GIO_REG_VAL_L0S_ENABLED);
-- 
2.18.4