[libvirt] [PATCH] qemuMonitorTextGetMemoryStats: decrease risk of false positive in parsing
Not urgent. This was highlighted by clang as a dead store, since the first result stored in "offset" was never used. But if "info balloon" were ever to print some introductory text (containing a comma) before the balloon: actual... line, the bug would have made a difference.
From c81c6af87f20740a6b75652937ec8346f8bf59e3 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering@redhat.com> Date: Fri, 5 Mar 2010 15:25:48 +0100 Subject: [PATCH] qemuMonitorTextGetMemoryStats: decrease risk of false positive in parsing
The code erroneously searched the entire "reply" for a comma, when its intent was to search only that portion after "balloon: actual=" * src/qemu/qemu_monitor_text.c (qemuMonitorTextGetMemoryStats): Search for "," only starting *after* the BALLOON_PREFIX string. Otherwise, we'd be more prone to false positives. --- src/qemu/qemu_monitor_text.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c index 7f0e7f6..e629c6b 100644 --- a/src/qemu/qemu_monitor_text.c +++ b/src/qemu/qemu_monitor_text.c @@ -593,7 +593,8 @@ int qemuMonitorTextGetMemoryStats(qemuMonitorPtr mon, } if ((offset = strstr(reply, BALLOON_PREFIX)) != NULL) { - if ((offset = strchr(reply, ',')) != NULL) { + offset += strlen(BALLOON_PREFIX); + if ((offset = strchr(offset, ',')) != NULL) { ret = qemuMonitorParseExtraBalloonInfo(offset, stats, nr_stats); } } -- 1.7.0.1.300.gd855a
On Fri, Mar 05, 2010 at 03:29:56PM +0100, Jim Meyering wrote:
Not urgent.
This was highlighted by clang as a dead store, since the first result stored in "offset" was never used. But if "info balloon" were ever to print some introductory text (containing a comma) before the balloon: actual... line, the bug would have made a difference.
From c81c6af87f20740a6b75652937ec8346f8bf59e3 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering@redhat.com> Date: Fri, 5 Mar 2010 15:25:48 +0100 Subject: [PATCH] qemuMonitorTextGetMemoryStats: decrease risk of false positive in parsing
The code erroneously searched the entire "reply" for a comma, when its intent was to search only that portion after "balloon: actual=" * src/qemu/qemu_monitor_text.c (qemuMonitorTextGetMemoryStats): Search for "," only starting *after* the BALLOON_PREFIX string. Otherwise, we'd be more prone to false positives. --- src/qemu/qemu_monitor_text.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c index 7f0e7f6..e629c6b 100644 --- a/src/qemu/qemu_monitor_text.c +++ b/src/qemu/qemu_monitor_text.c @@ -593,7 +593,8 @@ int qemuMonitorTextGetMemoryStats(qemuMonitorPtr mon, }
if ((offset = strstr(reply, BALLOON_PREFIX)) != NULL) { - if ((offset = strchr(reply, ',')) != NULL) { + offset += strlen(BALLOON_PREFIX); + if ((offset = strchr(offset, ',')) != NULL) { ret = qemuMonitorParseExtraBalloonInfo(offset, stats, nr_stats); } }
Right, it 'works' because BALLOON_PREFIX doesn't have a comma, but the patch makes the code consistent and more reliable, ACK, Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ daniel@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/
participants (2)
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Daniel Veillard -
Jim Meyering