From: Olaf Hering <olaf@aepfle.de>
Date: Tue, 16 Jan 2018 09:24:37 +0000 (+0100)
Subject: Fix parsing of features in detect_vm_xen_dom0 (#7890)
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=26dc3c373d72dcaa70e533d5d0ca626a02bf8785;p=elogind.git

Fix parsing of features in detect_vm_xen_dom0 (#7890)

Use sscanf instead of the built-in safe_atolu because the scanned string
lacks the leading "0x", it is generated with snprintf(b, "%08x", val).
As a result strtoull handles it as octal, and parsing fails.

The initial submission already used sscanf, then parsing was replaced by
safe_atolu without retesting the updated PR.

Fixes 575e6588d ("virt: use XENFEAT_dom0 to detect the hardware domain
(#6442, #6662) (#7581)")
---

diff --git a/src/basic/virt.c b/src/basic/virt.c
index 21e11b698..4c3791381 100644
--- a/src/basic/virt.c
+++ b/src/basic/virt.c
@@ -223,8 +223,8 @@ static int detect_vm_xen_dom0(void) {
         if (r == 0) {
                 unsigned long features;
 
-                r = safe_atolu(domcap, &features);
-                if (r == 0) {
+                r = sscanf(domcap, "%lx", &features);
+                if (r == 1) {
                         r = !!(features & (1U << XENFEAT_dom0));
                         log_debug("Virtualization XEN, found %s with value %08lx, "
                                   "XENFEAT_dom0 (indicating the 'hardware domain') is%s set.",