From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1kdaRO-0006ml-2U for mharc-qemu-trivial@gnu.org; Fri, 13 Nov 2020 09:52:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46402) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kdaRH-0006mG-WB; Fri, 13 Nov 2020 09:52:37 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:2419) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kdaRE-0002bU-DF; Fri, 13 Nov 2020 09:52:35 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4CXhJB472Hz15VTY; Fri, 13 Nov 2020 22:51:54 +0800 (CST) Received: from [10.174.187.138] (10.174.187.138) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Fri, 13 Nov 2020 22:51:55 +0800 Message-ID: <5FAE9D8B.9090209@huawei.com> Date: Fri, 13 Nov 2020 22:51:55 +0800 From: Alex Chen User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Markus Armbruster CC: , , Subject: Re: [PATCH] json: Fix a memleak in parse_pair() References: <20201111115609.48888-1-alex.chen@huawei.com> <87imabkrmm.fsf@dusky.pond.sub.org> In-Reply-To: <87imabkrmm.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.187.138] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.190; envelope-from=alex.chen@huawei.com; helo=szxga04-in.huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/13 09:52:06 X-ACL-Warn: Detected OS = Linux 3.1-3.10 [fuzzy] X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Nov 2020 14:52:38 -0000 On 2020/11/12 14:37, Markus Armbruster wrote: > Alex Chen writes: > >> In qobject_type(), NULL is returned when the 'QObject' returned from parse_value() is not of QString type, >> and this 'QObject' memory will leaked. >> So we need to first check whether the 'QObject' returned from parse_value() is of QString type, >> and if not, we free 'QObject' memory and return an error. >> >> The memleak stack is as follows: >> Direct leak of 32 byte(s) in 1 object(s) allocated from: >> #0 0xfffe4b3c34fb in __interceptor_malloc (/lib64/libasan.so.4+0xd34fb) >> #1 0xfffe4ae48aa3 in g_malloc (/lib64/libglib-2.0.so.0+0x58aa3) >> #2 0xaaab3557d9f7 in qnum_from_int /Images/source_org/qemu_master/qemu/qobject/qnum.c:25 >> #3 0xaaab35584d23 in parse_literal /Images/source_org/qemu_master/qemu/qobject/json-parser.c:511 >> #4 0xaaab35584d23 in parse_value /Images/source_org/qemu_master/qemu/qobject/json-parser.c:554 >> #5 0xaaab35583d77 in parse_pair /Images/source_org/qemu_master/qemu/qobject/json-parser.c:270 >> #6 0xaaab355845db in parse_object /Images/source_org/qemu_master/qemu/qobject/json-parser.c:327 >> #7 0xaaab355845db in parse_value /Images/source_org/qemu_master/qemu/qobject/json-parser.c:546 >> #8 0xaaab35585b1b in json_parser_parse /Images/source_org/qemu_master/qemu/qobject/json-parser.c:580 >> #9 0xaaab35583703 in json_message_process_token /Images/source_org/qemu_master/qemu/qobject/json-streamer.c:92 >> #10 0xaaab355ddccf in json_lexer_feed_char /Images/source_org/qemu_master/qemu/qobject/json-lexer.c:313 >> #11 0xaaab355de0eb in json_lexer_feed /Images/source_org/qemu_master/qemu/qobject/json-lexer.c:350 >> #12 0xaaab354aff67 in tcp_chr_read /Images/source_org/qemu_master/qemu/chardev/char-socket.c:525 >> #13 0xfffe4ae429db in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x529db) >> #14 0xfffe4ae42d8f (/lib64/libglib-2.0.so.0+0x52d8f) >> #15 0xfffe4ae430df in g_main_loop_run (/lib64/libglib-2.0.so.0+0x530df) >> #16 0xaaab34d70bff in iothread_run /Images/source_org/qemu_master/qemu/iothread.c:82 >> #17 0xaaab3559d71b in qemu_thread_start /Images/source_org/qemu_master/qemu/util/qemu-thread-posix.c:519 > > Good catch, thanks! > >> Fixes: 532fb5328473 ("qapi: Make more of qobject_to()") >> Reported-by: Euler Robot >> Signed-off-by: Alex Chen >> Signed-off-by: Chen Qun >> --- >> qobject/json-parser.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/qobject/json-parser.c b/qobject/json-parser.c >> index d083810d37..b37762a203 100644 >> --- a/qobject/json-parser.c >> +++ b/qobject/json-parser.c >> @@ -267,10 +267,13 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict) >> goto out; >> } >> >> - key = qobject_to(QString, parse_value(ctxt)); >> - if (!key) { >> - parse_error(ctxt, peek, "key is not a string in object"); >> + value = parse_value(ctxt); >> + if (!value || qobject_type(value) != QTYPE_QSTRING) { > > The "is string" test becomes more cumbersome. Also, we reuse @value for > another purpose. > >> + qobject_unref(value); >> + parse_error(ctxt, peek, "value is not a string in object"); > > Changing error messages in a memory leak fix is inappropriate. > Accident? > >> goto out; >> + } else { >> + key = qobject_to(QString, value); >> } >> >> token = parser_context_pop_token(ctxt); > > Here's a simpler, straightforward fix, with a test case thrown in: > > diff --git a/qobject/json-parser.c b/qobject/json-parser.c > index d083810d37..c0f521b56b 100644 > --- a/qobject/json-parser.c > +++ b/qobject/json-parser.c > @@ -257,8 +257,9 @@ static JSONToken *parser_context_peek_token(JSONParserContext *ctxt) > */ > static int parse_pair(JSONParserContext *ctxt, QDict *dict) > { > + QObject *key_obj = NULL; > + QString *key; > QObject *value; > - QString *key = NULL; > JSONToken *peek, *token; > > peek = parser_context_peek_token(ctxt); > @@ -267,7 +268,8 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict) > goto out; > } > > - key = qobject_to(QString, parse_value(ctxt)); > + key_obj = parse_value(ctxt); > + key = qobject_to(QString, key_obj); > if (!key) { > parse_error(ctxt, peek, "key is not a string in object"); > goto out; > @@ -297,13 +299,11 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict) > > qdict_put_obj(dict, qstring_get_str(key), value); > > - qobject_unref(key); > - > + qobject_unref(key_obj); > return 0; > > out: > - qobject_unref(key); > - > + qobject_unref(key_obj); > return -1; > } > > diff --git a/tests/check-qjson.c b/tests/check-qjson.c > index 07a773e653..9a02079099 100644 > --- a/tests/check-qjson.c > +++ b/tests/check-qjson.c > @@ -1415,6 +1415,14 @@ static void invalid_dict_comma(void) > g_assert(obj == NULL); > } > > +static void invalid_dict_key(void) > +{ > + Error *err = NULL; > + QObject *obj = qobject_from_json("{32:'abc'}", &err); > + error_free_or_abort(&err); > + g_assert(obj == NULL); > +} > + > static void unterminated_literal(void) > { > Error *err = NULL; > @@ -1500,6 +1508,7 @@ int main(int argc, char **argv) > g_test_add_func("/errors/unterminated/dict_comma", unterminated_dict_comma); > g_test_add_func("/errors/invalid_array_comma", invalid_array_comma); > g_test_add_func("/errors/invalid_dict_comma", invalid_dict_comma); > + g_test_add_func("/errors/invalid_dict_key", invalid_dict_key); > g_test_add_func("/errors/unterminated/literal", unterminated_literal); > g_test_add_func("/errors/limits/nesting", limits_nesting); > g_test_add_func("/errors/multiple_values", multiple_values); > Thanks for your review，your patch is better than mine. I will send the patch v2. 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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47840 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kdaSI-0007PK-JW for qemu-devel@archiver.kernel.org; Fri, 13 Nov 2020 09:53:38 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46402) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kdaRH-0006mG-WB; Fri, 13 Nov 2020 09:52:37 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:2419) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kdaRE-0002bU-DF; Fri, 13 Nov 2020 09:52:35 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4CXhJB472Hz15VTY; Fri, 13 Nov 2020 22:51:54 +0800 (CST) Received: from [10.174.187.138] (10.174.187.138) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Fri, 13 Nov 2020 22:51:55 +0800 Message-ID: <5FAE9D8B.9090209@huawei.com> Date: Fri, 13 Nov 2020 22:51:55 +0800 From: Alex Chen User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Markus Armbruster Subject: Re: [PATCH] json: Fix a memleak in parse_pair() References: <20201111115609.48888-1-alex.chen@huawei.com> <87imabkrmm.fsf@dusky.pond.sub.org> In-Reply-To: <87imabkrmm.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.187.138] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.190; envelope-from=alex.chen@huawei.com; helo=szxga04-in.huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/13 09:52:06 X-ACL-Warn: Detected OS = Linux 3.1-3.10 [fuzzy] X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-trivial@nongnu.org, qemu-devel@nongnu.org, zhang.zhanghailiang@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/11/12 14:37, Markus Armbruster wrote: > Alex Chen writes: > >> In qobject_type(), NULL is returned when the 'QObject' returned from parse_value() is not of QString type, >> and this 'QObject' memory will leaked. >> So we need to first check whether the 'QObject' returned from parse_value() is of QString type, >> and if not, we free 'QObject' memory and return an error. >> >> The memleak stack is as follows: >> Direct leak of 32 byte(s) in 1 object(s) allocated from: >> #0 0xfffe4b3c34fb in __interceptor_malloc (/lib64/libasan.so.4+0xd34fb) >> #1 0xfffe4ae48aa3 in g_malloc (/lib64/libglib-2.0.so.0+0x58aa3) >> #2 0xaaab3557d9f7 in qnum_from_int /Images/source_org/qemu_master/qemu/qobject/qnum.c:25 >> #3 0xaaab35584d23 in parse_literal /Images/source_org/qemu_master/qemu/qobject/json-parser.c:511 >> #4 0xaaab35584d23 in parse_value /Images/source_org/qemu_master/qemu/qobject/json-parser.c:554 >> #5 0xaaab35583d77 in parse_pair /Images/source_org/qemu_master/qemu/qobject/json-parser.c:270 >> #6 0xaaab355845db in parse_object /Images/source_org/qemu_master/qemu/qobject/json-parser.c:327 >> #7 0xaaab355845db in parse_value /Images/source_org/qemu_master/qemu/qobject/json-parser.c:546 >> #8 0xaaab35585b1b in json_parser_parse /Images/source_org/qemu_master/qemu/qobject/json-parser.c:580 >> #9 0xaaab35583703 in json_message_process_token /Images/source_org/qemu_master/qemu/qobject/json-streamer.c:92 >> #10 0xaaab355ddccf in json_lexer_feed_char /Images/source_org/qemu_master/qemu/qobject/json-lexer.c:313 >> #11 0xaaab355de0eb in json_lexer_feed /Images/source_org/qemu_master/qemu/qobject/json-lexer.c:350 >> #12 0xaaab354aff67 in tcp_chr_read /Images/source_org/qemu_master/qemu/chardev/char-socket.c:525 >> #13 0xfffe4ae429db in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x529db) >> #14 0xfffe4ae42d8f (/lib64/libglib-2.0.so.0+0x52d8f) >> #15 0xfffe4ae430df in g_main_loop_run (/lib64/libglib-2.0.so.0+0x530df) >> #16 0xaaab34d70bff in iothread_run /Images/source_org/qemu_master/qemu/iothread.c:82 >> #17 0xaaab3559d71b in qemu_thread_start /Images/source_org/qemu_master/qemu/util/qemu-thread-posix.c:519 > > Good catch, thanks! > >> Fixes: 532fb5328473 ("qapi: Make more of qobject_to()") >> Reported-by: Euler Robot >> Signed-off-by: Alex Chen >> Signed-off-by: Chen Qun >> --- >> qobject/json-parser.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/qobject/json-parser.c b/qobject/json-parser.c >> index d083810d37..b37762a203 100644 >> --- a/qobject/json-parser.c >> +++ b/qobject/json-parser.c >> @@ -267,10 +267,13 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict) >> goto out; >> } >> >> - key = qobject_to(QString, parse_value(ctxt)); >> - if (!key) { >> - parse_error(ctxt, peek, "key is not a string in object"); >> + value = parse_value(ctxt); >> + if (!value || qobject_type(value) != QTYPE_QSTRING) { > > The "is string" test becomes more cumbersome. Also, we reuse @value for > another purpose. > >> + qobject_unref(value); >> + parse_error(ctxt, peek, "value is not a string in object"); > > Changing error messages in a memory leak fix is inappropriate. > Accident? > >> goto out; >> + } else { >> + key = qobject_to(QString, value); >> } >> >> token = parser_context_pop_token(ctxt); > > Here's a simpler, straightforward fix, with a test case thrown in: > > diff --git a/qobject/json-parser.c b/qobject/json-parser.c > index d083810d37..c0f521b56b 100644 > --- a/qobject/json-parser.c > +++ b/qobject/json-parser.c > @@ -257,8 +257,9 @@ static JSONToken *parser_context_peek_token(JSONParserContext *ctxt) > */ > static int parse_pair(JSONParserContext *ctxt, QDict *dict) > { > + QObject *key_obj = NULL; > + QString *key; > QObject *value; > - QString *key = NULL; > JSONToken *peek, *token; > > peek = parser_context_peek_token(ctxt); > @@ -267,7 +268,8 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict) > goto out; > } > > - key = qobject_to(QString, parse_value(ctxt)); > + key_obj = parse_value(ctxt); > + key = qobject_to(QString, key_obj); > if (!key) { > parse_error(ctxt, peek, "key is not a string in object"); > goto out; > @@ -297,13 +299,11 @@ static int parse_pair(JSONParserContext *ctxt, QDict *dict) > > qdict_put_obj(dict, qstring_get_str(key), value); > > - qobject_unref(key); > - > + qobject_unref(key_obj); > return 0; > > out: > - qobject_unref(key); > - > + qobject_unref(key_obj); > return -1; > } > > diff --git a/tests/check-qjson.c b/tests/check-qjson.c > index 07a773e653..9a02079099 100644 > --- a/tests/check-qjson.c > +++ b/tests/check-qjson.c > @@ -1415,6 +1415,14 @@ static void invalid_dict_comma(void) > g_assert(obj == NULL); > } > > +static void invalid_dict_key(void) > +{ > + Error *err = NULL; > + QObject *obj = qobject_from_json("{32:'abc'}", &err); > + error_free_or_abort(&err); > + g_assert(obj == NULL); > +} > + > static void unterminated_literal(void) > { > Error *err = NULL; > @@ -1500,6 +1508,7 @@ int main(int argc, char **argv) > g_test_add_func("/errors/unterminated/dict_comma", unterminated_dict_comma); > g_test_add_func("/errors/invalid_array_comma", invalid_array_comma); > g_test_add_func("/errors/invalid_dict_comma", invalid_dict_comma); > + g_test_add_func("/errors/invalid_dict_key", invalid_dict_key); > g_test_add_func("/errors/unterminated/literal", unterminated_literal); > g_test_add_func("/errors/limits/nesting", limits_nesting); > g_test_add_func("/errors/multiple_values", multiple_values); > Thanks for your review，your patch is better than mine. I will send the patch v2. Thanks, Alex