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authorLaszlo Ersek <lersek@redhat.com>2013-08-20 00:35:38 +0200
committerLuiz Capitulino <lcapitulino@redhat.com>2013-08-20 11:52:00 -0400
commit15a849be100b54776bcf63193c3fea598666030f (patch)
treef41db9777be6929ef8052c2d8a92fab294873935
parent581a8a800070500527f6c75e5d6b75134c2b5a9d (diff)
OptsVisitor: don't try to flatten overlong integer ranges
Prevent mistyped command line options from incurring high memory and CPU usage at startup. 64K elements in a range should be enough for everyone (TM). The OPTS_VISITOR_RANGE_MAX macro is public so that unit tests can construct corner cases with it. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
-rw-r--r--include/qapi/opts-visitor.h6
-rw-r--r--qapi/opts-visitor.c7
2 files changed, 11 insertions, 2 deletions
diff --git a/include/qapi/opts-visitor.h b/include/qapi/opts-visitor.h
index 5939eeebc7..fd48c14ec8 100644
--- a/include/qapi/opts-visitor.h
+++ b/include/qapi/opts-visitor.h
@@ -16,6 +16,12 @@
#include "qapi/visitor.h"
#include "qemu/option.h"
+/* Inclusive upper bound on the size of any flattened range. This is a safety
+ * (= anti-annoyance) measure; wrong ranges should not cause long startup
+ * delays nor exhaust virtual memory.
+ */
+#define OPTS_VISITOR_RANGE_MAX 65536
+
typedef struct OptsVisitor OptsVisitor;
/* Contrarily to qemu-option.c::parse_option_number(), OptsVisitor's "int"
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
index d54d373188..96ed85899d 100644
--- a/qapi/opts-visitor.c
+++ b/qapi/opts-visitor.c
@@ -384,7 +384,9 @@ opts_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
str = endptr + 1;
val2 = strtoll(str, &endptr, 0);
if (errno == 0 && endptr > str && *endptr == '\0' &&
- INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2) {
+ INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2 &&
+ (val > INT64_MAX - OPTS_VISITOR_RANGE_MAX ||
+ val2 < val + OPTS_VISITOR_RANGE_MAX)) {
ov->range_next.s = val;
ov->range_limit.s = val2;
ov->list_mode = LM_SIGNED_INTERVAL;
@@ -435,7 +437,8 @@ opts_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp)
str = endptr + 1;
if (parse_uint_full(str, &val2, 0) == 0 &&
- val2 <= UINT64_MAX && val <= val2) {
+ val2 <= UINT64_MAX && val <= val2 &&
+ val2 - val < OPTS_VISITOR_RANGE_MAX) {
ov->range_next.u = val;
ov->range_limit.u = val2;
ov->list_mode = LM_UNSIGNED_INTERVAL;