[SSSD] [PATCHES] dyndns: Fix talloc hierarchy of "struct sss_iface_addr"

Lukas Slebodnik lslebodn at redhat.com
Thu Aug 21 18:14:50 UTC 2014


On (21/08/14 18:58), Jakub Hrozek wrote:
>On Thu, Aug 21, 2014 at 10:25:08AM +0200, Lukas Slebodnik wrote:
>> ehlo
>> 
>> 0001-dyndns_test-Use-right-socket-length-of-for-IPv4-addr.patch
>>     not very important patch.
>> 
>> 0002-responder-get-domains-tests-fix-checking-of-leaks.patch
>> 0003-test_dyndns-Use-different-talloc-context-in-wrapped-.patch
>>     previous two patches are necessary for 4th patch
>> 
>> 0004-TESTS-leak_check-functions-shouldn-t-be-called-with-.patch
>>     Wit this patch it will be possible to cach mem leak in 6th patch
>> 
>> 0005-dyndns-Fix-talloc-hierarchy-of-struct-sss_iface_addr.patch
>>     this simpepatch fix use after free problem in ticket #2405
>> 
>> 0006-test_dyndns-sss_iface_addr_list_get-can-return-more-.patch
>>     test for previous patch. You can try to revert 5th patch
>>     and you will see memory leak (not all data were moved to appropriate
>>             talloc context)
>> 
>> Leak report for ../sssd/src/tests/cmocka/test_dyndns.c:247:
>> full talloc report on 'struct dyndns_test_ctx' (total     80 bytes in   3 blocks)
>>     struct sss_iface_addr          contains     40 bytes in   2 blocks (ref 0) 0x1469c20
>>         ../sssd/src/providers/dp_dyndns.c:210 contains     16 bytes in   1 blocks (ref 0) 0x1469990
>> check_leaks_pop(dyndns_test_ctx) == true
>> ../sssd/src/tests/cmocka/test_dyndns.c:247: error: Failure!
>> [  FAILED  ] dyndns_test_get_multi_ifaddr
>> 
>> 0007-SDAP-free-subrequest-in-sdap_dyndns_update_addrs_don.patch
>>     subrequest can be freed after fixing talloc hierarchy in 5th patch.
>> 
>> How to test.
>> two IP addresses shoudl be used in ptr update. You can use valgrind to see use
>> after free error.
>> 
>> The other option is to export env variable TALLOC_FREE_FILL=255 and sssd_be
>> will crash in function resolv_get_string_ptr_address
>> 
>> LS
>
>> From c1dcfbf48ad07d3ac34f2085272e64666a0b4239 Mon Sep 17 00:00:00 2001
>> From: Lukas Slebodnik <lslebodn at redhat.com>
>> Date: Wed, 20 Aug 2014 17:32:04 +0200
>> Subject: [PATCH 1/7] dyndns_test: Use right socket length of for IPv4 address.
>> 
>> man inet_ntop says:
>>   The caller specifies the number of bytes available in this buffer
>>   in the argument size.
>> 
>>    AF_INET
>>           src points to a struct in_addr (in network byte order) which is
>>           converted to an IPv4 network address in the dotted-decimal
>>           format, "ddd.ddd.ddd.ddd". The buffer dst must be at least
>>           INET_ADDRSTRLEN bytes long.
>> ---
>>  src/tests/cmocka/test_dyndns.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/src/tests/cmocka/test_dyndns.c b/src/tests/cmocka/test_dyndns.c
>> index b0e8df81bc079efa8ebd8ae45603921261330c9b..b7e45a19db5dd9e85260029fe81e46aa18c1c8ed 100644
>> --- a/src/tests/cmocka/test_dyndns.c
>> +++ b/src/tests/cmocka/test_dyndns.c
>> @@ -194,7 +194,7 @@ void dyndns_test_get_ifaddr(void **state)
>>  
>>      assert_non_null(inet_ntop(AF_INET,
>>                                &((struct sockaddr_in *) addrlist->addr)->sin_addr,
>> -                              straddr, INET6_ADDRSTRLEN));
>> +                              straddr, INET_ADDRSTRLEN));
>
>Does it make sense to also use INET_ADDRSTRLEN+1 for the straddr length,
>too?
>
maximul length of IPV4 address is 15 "ddd.ddd.ddd.ddd"

sh-4.3$ grep -RniI INET_ADDRSTRLEN
netinet/in.h:232:#define INET_ADDRSTRLEN 16

BTW man inet_ntop says:
     The caller specifies the number of bytes available in this buffer
     in the argument size.                    ^^^^^^^^^

     The buffer dst must be at least INET_ADDRSTRLEN bytes long.
                            ^^^^^^^^
In teory, this patch is not needed, because constant INET6_ADDRSTRLEN is longer
than INET_ADDRSTRLEN

LS



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