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[Qemu-devel] [PULL 07/11] OptsVisitor: don't try to flatten overlong int
From: |
Luiz Capitulino |
Subject: |
[Qemu-devel] [PULL 07/11] OptsVisitor: don't try to flatten overlong integer ranges |
Date: |
Tue, 20 Aug 2013 12:10:37 -0400 |
From: Laszlo Ersek <address@hidden>
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 <address@hidden>
Tested-by: Wanlong Gao <address@hidden>
Signed-off-by: Luiz Capitulino <address@hidden>
---
include/qapi/opts-visitor.h | 6 ++++++
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 5939eee..fd48c14 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 d54d373..96ed858 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;
--
1.8.1.4
- [Qemu-devel] [PULL 05/11] OptsVisitor: rebase opts_type_uint64() to parse_uint_full(), (continued)
- [Qemu-devel] [PULL 05/11] OptsVisitor: rebase opts_type_uint64() to parse_uint_full(), Luiz Capitulino, 2013/08/20
- [Qemu-devel] [PULL 01/11] Convert stderr message calling error_get_pretty() to error_report(), Luiz Capitulino, 2013/08/20
- [Qemu-devel] [PULL 06/11] OptsVisitor: opts_type_uint64(): recognize intervals when LM_IN_PROGRESS, Luiz Capitulino, 2013/08/20
- [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Luiz Capitulino, 2013/08/20
- Re: [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Andreas Färber, 2013/08/20
- Re: [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Luiz Capitulino, 2013/08/20
- Re: [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Andreas Färber, 2013/08/20
- Re: [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Laszlo Ersek, 2013/08/21
- Re: [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Eric Blake, 2013/08/21
- Re: [Qemu-devel] [PULL 08/11] add "test-int128" and "test-bitops" to .gitignore, Markus Armbruster, 2013/08/22
[Qemu-devel] [PULL 07/11] OptsVisitor: don't try to flatten overlong integer ranges,
Luiz Capitulino <=
[Qemu-devel] [PULL 09/11] OptsVisitor: introduce unit tests, with test cases for range flattening, Luiz Capitulino, 2013/08/20
[Qemu-devel] [PULL 11/11] scripts/qapi.py: Avoid syntax not supported by Python 2.4, Luiz Capitulino, 2013/08/20
[Qemu-devel] [PULL 10/11] monitor: print the invalid char in error message, Luiz Capitulino, 2013/08/20