linux-kernel - [Debug 2/2] x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs

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]

Date:	Tue,  3 Mar 2015 12:25:41 +0800
From:	Jiang Liu <jiang.liu@...ux.intel.com>
To:	"Rafael J . Wysocki" <rjw@...ysocki.net>,
	Thomas Voegtle <tv@...96.de>, Hudd <hedede.l@...il.com>,
	Prakash Punnoor <prakash@...noor.de>,
	Francois Romieu <romieu@...zoreil.com>,
	Dave Airlie <airlied@...il.com>,
	Marcel Holtmann <marcel@...tmann.org>,
	Len Brown <lenb@...nel.org>
Cc:	Jiang Liu <jiang.liu@...ux.intel.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	LKML <linux-kernel@...r.kernel.org>, linux-pci@...r.kernel.org,
	linux-acpi@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Lv Zheng <lv.zheng@...el.com>
Subject: [Debug 2/2] x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs

Some BIOSes report incorrect length for ACPI address space descriptors,
so relax the checks to avoid regressions.

Signed-off-by: Jiang Liu <jiang.liu@...ux.intel.com>
---
 drivers/acpi/resource.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index c723668e3e27..5589a6e2a023 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -42,8 +42,10 @@ static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
 	 * CHECKME: len might be required to check versus a minimum
 	 * length as well. 1 for io is fine, but for memory it does
 	 * not make any sense at all.
+	 * Note: some BIOSes report incorrect length for ACPI address space
+	 * descriptor, so remove check of 'reslen == len' to avoid regression.
 	 */
-	if (len && reslen && reslen == len && start <= end)
+	if (len && reslen && start <= end)
 		return true;
 
 	pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/