From cbf97d5b799f4bc47b9e825100d1a98d3cf77c80 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Thu, 16 Jul 2020 17:06:17 +0200 Subject: [PATCH] qapi: Fix visit_type_STRUCT() not to fail for null object To make deallocating partially constructed objects work, the visit_type_STRUCT() need to succeed without doing anything when passed a null object. Commit cdd2b228b9 "qapi: Smooth visitor error checking in generated code" broke that. To reproduce, run tests/test-qobject-input-visitor with AddressSanitizer: ==4353==ERROR: LeakSanitizer: detected memory leaks Direct leak of 16 byte(s) in 1 object(s) allocated from: #0 0x7f192d0c5d28 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28) #1 0x7f192cd21b10 in g_malloc0 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51b10) #2 0x556725f6bbee in visit_next_list qapi/qapi-visit-core.c:86 #3 0x556725f49e15 in visit_type_UserDefOneList tests/test-qapi-visit.c:474 #4 0x556725f4489b in test_visitor_in_fail_struct_in_list tests/test-qobject-input-visitor.c:1086 #5 0x7f192cd42f29 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72f29) SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s). Test case /visitor/input/fail/struct-in-list feeds a list with a bad element to the QObject input visitor. Visiting that element duly fails, and aborts the visit with the list only partially constructed: the faulty object is null. Cleaning up the partially constructed list visits that null object, fails, and aborts the visit before the list node gets freed. Fix the the generated visit_type_STRUCT() to succeed for null objects. Fixes: cdd2b228b973d2a29edf7696ef6e8b08ec329019 Reported-by: Li Qiang Signed-off-by: Markus Armbruster Message-Id: <20200716150617.4027356-1-armbru@redhat.com> Tested-by: Li Qiang Reviewed-by: Li Qiang --- scripts/qapi/visit.py | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py index 3fb2f30510b2..cdabc5fa283b 100644 --- a/scripts/qapi/visit.py +++ b/scripts/qapi/visit.py @@ -249,6 +249,7 @@ def gen_visit_object(name, base, members, variants): if (!*obj) { /* incomplete */ assert(visit_is_dealloc(v)); + ok = true; goto out_obj; } if (!visit_type_%(c_name)s_members(v, *obj, errp)) {