Locate a memory leak in tools modules

["Rroach" <2284696125@xxxxxx>]

Hi, I'm attempting to use address sanitizer in locating bugs in Xen 4-13, while use address sanitizer in tools modules, while I ran some basic instructions like xl, Xen report such bug:

=================================================================
==2863==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 296 byte(s) in 11 object(s) allocated from:
    #0 0x7f5b91aefd28 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.3+0xc1d28)
    #1 0x467997  (/usr/bin/x86_64-linux-gnu-gcc-6+0x467997)

Indirect leak of 10 byte(s) in 1 object(s) allocated from:
    #0 0x7f5b91aefd28 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.3+0xc1d28)
    #1 0x467997  (/usr/bin/x86_64-linux-gnu-gcc-6+0x467997)

SUMMARY: AddressSanitizer: 306 byte(s) leaked in 12 allocation(s).
/root/faultxen/tools/libs/toolcore/../../../tools/Rules.mk:224: recipe for target 'headers.chk' failed
make[5]: *** [headers.chk] Error 1

==7520==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 10 byte(s) in 1 object(s) allocated from:
    #0 0x7fd1028c8d28 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.3+0xc1d28)
    #1 0x7fd1022e43b9 in __strdup (/lib/x86_64-linux-gnu/libc.so.6+0x803b9)

SUMMARY: AddressSanitizer: 10 byte(s) leaked in 1 allocation(s).
=================================================================

It seems this bug is very low-level, and affects many basic operations, do you have any idea what cause such bugs?