diff options
| author | Laszlo Ersek <lersek@redhat.com> | 2013-08-20 00:35:38 +0200 |
|---|---|---|
| committer | Luiz Capitulino <lcapitulino@redhat.com> | 2013-08-20 11:52:00 -0400 |
| commit | 15a849be100b54776bcf63193c3fea598666030f (patch) | |
| tree | f41db9777be6929ef8052c2d8a92fab294873935 | |
| parent | 581a8a800070500527f6c75e5d6b75134c2b5a9d (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.h | 6 | ||||
| -rw-r--r-- | qapi/opts-visitor.c | 7 |
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; |