{ ZLib doesn't allocate its buffer. This is no bug according to the FAQ. Memcheck:Cond fun:longest_match fun:deflate_slow fun:deflate } { Not sure why this happens. Memcheck:Leak fun:calloc fun:_dl_allocate_tls fun:pthread_create@@GLIBC_2.1 fun:_ZN5boost6thread12start_threadEv } { <insert_a_suppression_name_here> Memcheck:Leak fun:malloc fun:__cxa_get_globals fun:__cxa_allocate_exception fun:_ZN5boost14copy_exceptionINS_16exception_detail10bad_alloc_EEENS_10shared_ptrIKNS1_10clone_baseEEERKT_ fun:_ZN5boost16exception_detail13get_bad_allocILi42EEENS_10shared_ptrIKNS0_10clone_baseEEEv fun:_Z41__static_initialization_and_destruction_0ii fun:_GLOBAL__I__ZN12_GLOBAL__N_12_1E fun:_ZN16ImageLoaderMachO18doModInitFunctionsERKN11ImageLoader11LinkContextE fun:_ZN11ImageLoader23recursiveInitializationERKNS_11LinkContextEj fun:_ZN11ImageLoader15runInitializersERKNS_11LinkContextE fun:_ZN4dyld24initializeMainExecutableEv fun:_ZN4dyld5_mainEPK12macho_headermiPPKcS5_S5_ } { <insert a suppression name here> Memcheck:Param socketcall.sendto(msg) fun:sendto fun:getaddrinfo } { <insert a suppression name here> Memcheck:Cond fun:BN_bin2bn } { <insert a suppression name here> Memcheck:Cond fun:BN_num_bits_word } { <insert a suppression name here> Memcheck:Value4 fun:BN_mod_exp_mont_consttime fun:BN_mod_exp_mont } { <insert a suppression name here> Memcheck:Value4 fun:BN_num_bits_word fun:BN_mod_exp_mont_consttime fun:BN_mod_exp_mont }