dwfl crash

repro.c

#include <dwarf.h>
#include <elfutils/libdwelf.h>
#include <elfutils/libdwfl.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>


static int module_callback (Dwfl_Module *mod, void **userdata, const char *name, Dwarf_Addr start, void *arg)
{
        const unsigned char *id;
        GElf_Addr id_vaddr;
        int id_len;

        assert(mod);

        id_len = dwfl_module_build_id(mod, &id, &id_vaddr);
        printf("build-id of size %d\n", id_len);

        GElf_Addr *bias = NULL;
        Elf *elf = dwfl_module_getelf(mod, bias);
        if (!elf) {
                printf("elf_begin() failed: %s\n", elf_errmsg(-1));
                return DWARF_CB_ABORT;
        }

        return DWARF_CB_OK;
}

int main(int argc, char **argv) {

        static const Dwfl_Callbacks callbacks = {
                .find_elf = dwfl_build_id_find_elf,
                .section_address = dwfl_offline_section_address,
                .find_debuginfo = dwfl_standard_find_debuginfo,
        };

        Dwfl *dwfl = NULL;
        Elf *elf = NULL;
        int r;
        int fd;

        assert(argc > 1);

        fd = open(argv[1], O_CLOEXEC|O_RDONLY);
        if (fd < 0)
                return -1;

        elf_version(EV_CURRENT);

        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
        if (!elf) {
                r = -EINVAL;
                goto finish;
        }

        dwfl = dwfl_begin(&callbacks);
        if (!dwfl) {
                r = -EINVAL;
                goto finish;
        }

        if (dwfl_core_file_report(dwfl, elf, "/usr/bin/sleep") < 0) {
                r = -EINVAL;
                goto finish;
        }

        if (dwfl_report_end(dwfl, NULL, NULL) != 0) {
                r = -EINVAL;
                goto finish;
        }

        if (dwfl_getmodules(dwfl, &module_callback, NULL, 0) < 0) {
                r = -EINVAL;
                goto finish;
        }

        r = 0;

finish:
        if (dwfl)
                dwfl_end(dwfl);

        if (elf)
                elf_end(elf);

        close(fd);

        return r;
}