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[Qemu-devel] [PATCH v3 for-2.5 02/12] qjson: Don't crash when input exce
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v3 for-2.5 02/12] qjson: Don't crash when input exceeds nesting limit |
Date: |
Wed, 25 Nov 2015 22:23:23 +0100 |
We limit nesting depth and input size to defend against input
triggering excessive heap or stack memory use (commit 29c75dd
json-streamer: limit the maximum recursion depth and maximum token
count). However, when the nesting limit is exceeded,
parser_context_peek_token()'s assertion fails.
Broken in commit 65c0f1e "json-parser: don't replicate tokens at each
level of recursion".
To reproduce stuff 1025 open braces or brackets into QMP.
Fix by taking the error exit instead of the normal one.
Reported-by: Eric Blake <address@hidden>
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
qobject/json-streamer.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c
index dced2c7..2bd22a7 100644
--- a/qobject/json-streamer.c
+++ b/qobject/json-streamer.c
@@ -68,13 +68,14 @@ static void json_message_process_token(JSONLexer *lexer,
QString *token, JSONTok
/* Security consideration, we limit total memory allocated per object
* and the maximum recursion depth that a message can force.
*/
- goto out_emit;
+ goto out_emit_bad;
}
return;
out_emit_bad:
- /* clear out token list and tell the parser to emit and error
+ /*
+ * Clear out token list and tell the parser to emit an error
* indication by passing it a NULL list
*/
QDECREF(parser->tokens);
--
2.4.3
- [Qemu-devel] [PATCH v3 for-2.5 03/12] check-qjson: Add test for JSON nesting depth limit, (continued)
- [Qemu-devel] [PATCH v3 for-2.5 03/12] check-qjson: Add test for JSON nesting depth limit, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 04/12] qjson: Spell out some silent assumptions, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 12/12] qjson: Limit number of tokens in addition to total size, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 08/12] qjson: replace QString in JSONLexer with GString, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 09/12] qjson: Convert to parser to recursive descent, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 02/12] qjson: Don't crash when input exceeds nesting limit,
Markus Armbruster <=
- [Qemu-devel] [PATCH v3 for-2.5 10/12] qjson: store tokens in a GQueue, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 11/12] qjson: surprise, allocating 6 QObjects per token is expensive, Markus Armbruster, 2015/11/25
- [Qemu-devel] [PATCH v3 for-2.5 05/12] qjson: Give each of the six structural chars its own token type, Markus Armbruster, 2015/11/25