linux-kernel - [PATCH] x86:sysfb_efi:efifb_set_system: fix miss valid address range in later BARs

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>] [day] [month] [year] [list]

Message-ID: <20160411032221.GA13983@udknight>
Date:	Mon, 11 Apr 2016 11:22:21 +0800
From:	Wang YanQing <udknight@...il.com>
To:	tomi.valkeinen@...com
Cc:	pjones@...hat.com, dh.herrmann@...il.com, hpa@...or.com,
	linux-kernel@...r.kernel.org, x86@...nel.org
Subject: [PATCH] x86:sysfb_efi:efifb_set_system: fix miss valid address range
 in later BARs

We can't just break out when meet start is equal to zero,
this will cause we miss valid address range in later BARs.

On the other hand, it isn't enough to test start only
for below situation:
0(start) <= lfb_base < end

Signed-off-by: Wang YanQing <udknight@...il.com>
---
 arch/x86/kernel/sysfb_efi.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/sysfb_efi.c b/arch/x86/kernel/sysfb_efi.c
index b285d4e..ac0b521 100644
--- a/arch/x86/kernel/sysfb_efi.c
+++ b/arch/x86/kernel/sysfb_efi.c
@@ -106,10 +106,19 @@ static int __init efifb_set_system(const struct dmi_system_id *id)
 					continue;
 				for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
 					resource_size_t start, end;
+					unsigned long flags;
+
+					flags = pci_resource_flags(dev, i);
+					if (!(flags & IORESOURCE_MEM))
+						continue;
+
+					if (flags & IORESOURCE_UNSET)
+						continue;
+
+					if (pci_resource_len(dev, i) == 0)
+						continue;
 
 					start = pci_resource_start(dev, i);
-					if (start == 0)
-						break;
 					end = pci_resource_end(dev, i);
 					if (screen_info.lfb_base >= start &&
 					    screen_info.lfb_base < end) {
-- 
1.8.5.6.2.g3d8a54e.dirty