# New Ticket Created by Brian Carpenter # Please include the string: [perl #129903] # in the subject line of all future correspondence about this issue. # <URL: https://rt.perl.org/Ticket/Display.html?id=129903 > I'm not convinced that this is an actual bug, but #p5p was silent when I asked about it. Affects Perl back to 5.20.2 including v5.25.6 (v5.25.5-114-g87af8d5). Valgrind fails pretty quickly but gdb just goes on forever. perl -e '/(?{m}(0)},s\/\/\/})//0' ==6615==ERROR: AddressSanitizer: stack-overflow on address 0x7ffc78f88ca8 (pc 0x0000004c0d4c bp 0x7ffc78f89500 sp 0x7ffc78f88cb0 T0) #0 0x4c0d4b in calloc (/root/perl/perl+0x4c0d4b) #1 0x7f9301 in Perl_safesyscalloc /root/perl/util.c:442:18 #2 0xb45aed in Perl_regexec_flags /root/perl/regexec.c:3128:9 #3 0x8cf9c5 in Perl_pp_subst /root/perl/pp_hot.c:2981:10 #4 0x7f4483 in Perl_runops_debug /root/perl/dump.c:2246:23 #5 0xb984b6 in S_regmatch /root/perl/regexec.c:6888:3 #6 0xb7337c in S_regtry /root/perl/regexec.c:3622:14 ... ... #247 0xb4b82b in Perl_regexec_flags /root/perl/regexec.c:3489:7 #248 0x8cf9c5 in Perl_pp_subst /root/perl/pp_hot.c:2981:10 #249 0x7f4483 in Perl_runops_debug /root/perl/dump.c:2246:23 #250 0xb984b6 in S_regmatch /root/perl/regexec.c:6888:3 #251 0xb7337c in S_regtry /root/perl/regexec.c:3622:14 SUMMARY: AddressSanitizer: stack-overflow ??:0 calloc ==6615==ABORTING ==19424== Stack overflow in thread 1: can't grow stack to 0xffe801f90 ==19424== ==19424== Process terminating with default action of signal 11 (SIGSEGV) ==19424== Access not within mapped region at address 0xFFE801F90 ==19424== at 0x5B4137: S_regtry (regexec.c:3578) ==19424== If you believe this happened as a result of a stack ==19424== overflow in your program's main thread (unlikely but ==19424== possible), you can try to increase the size of the ==19424== main thread stack using the --main-stacksize= flag. ==19424== The main thread stack size used in this run was 8388608. ==19424== Stack overflow in thread 1: can't grow stack to 0xffe801f88 ==19424== ==19424== Process terminating with default action of signal 11 (SIGSEGV) ==19424== Access not within mapped region at address 0xFFE801F88 ==19424== at 0x4A236C0: _vgnU_freeres (vg_preloaded.c:58) ==19424== If you believe this happened as a result of a stack ==19424== overflow in your program's main thread (unlikely but ==19424== possible), you can try to increase the size of the ==19424== main thread stack using the --main-stacksize= flag. ==19424== The main thread stack size used in this run was 8388608. Segmentation faultThread Previous