ASan reports pointer overflow

[edeiana]

Address Sanitizer reports pointer overflow when performing pointer arithmetic with final_pc.
This happens when final_pc is NULL, as adding to it is undefined behavior.
We cast final_pc (which is an app_pc aka unsigned char *) to unsigned integer to fix the issue.

[vitalybuka]

Detected reports:

core/ir/instrlist.c:575:18: runtime error: applying non-zero offset 4 to null pointer
    #0 ir/instrlist.c:575:18
    #1 dynamorio::drmemtrace::add_encodings_to_memrefs drmemtrace/memref_gen.h:198:9

core/ir/aarch64/codec.c:1084:62: runtime error: applying non-zero offset 16 to null pointer
    #0 decode_opnd_adr_page core/ir/aarch64/codec.c:1084:62
    #1 decode_opnds_adr core/ir/aarch64/codec.c:9156:10
    #2 decoder_v80 arm/decode_gen_v80.h
    #3 decode_common core/ir/aarch64/codec.c:9581:10
    #4 decode_from_copy core/ir/aarch64/decode.c:100:12

core/ir/x86/encode.c:3024:67: runtime error: applying non-zero offset 6 to null pointer
    #0 encode_cti core/ir/x86/encode.c:3024:67
    #1 instr_encode_arch core/ir/x86/encode.c:3173:20
    #2 instr_encode_common core/ir/encode_shared.c:129:12
    #3 instr_encode_to_copy core/ir/encode_shared.c:153:12
    #4 instrlist_encode_to_copy core/ir/instrlist.c:572:20
    #5 dynamorio::drmemtrace::add_encodings_to_memrefs drmemtrace/memref_gen.h:198:9

clients/drcachesim/tracer/raw2trace_shared.cpp:290:78: runtime error: applying non-zero offset 4096 to null pointer
    #0 dynamorio::drmemtrace::module_mapper_t::read_and_map_modules() clients/drcachesim/tracer/raw2trace_shared.cpp:290:78
    #1 dynamorio::drmemtrace::module_mapper_t::get_loaded_modules() clients/drcachesim/tracer/raw2trace_shared.h:270:13

core/drlibc/drlibc_module_elf.c:201:55: runtime error: applying non-zero offset 126787216 to null pointer
    #0 module_vaddr_from_prog_header core/drlibc/drlibc_module_elf.c:201:55
    #1 elf_loader_map_phdrs core/drlibc/drlibc_module_elf.c:397:16
    #2 privload_map_and_relocate core/unix/loader.c:571:12
    #3 dr_map_executable_file core/lib/instrument.c:3997:12
    #4 dynamorio::drmemtrace::module_mapper_t::read_and_map_modules() clients/drcachesim/tracer/raw2trace_shared.cpp:333:21
    #5 dynamorio::drmemtrace::module_mapper_t::get_loaded_modules() clients/drcachesim/tracer/raw2trace_shared.h:270:13

drlibc/drlibc_module_elf.c:459:77: runtime error: applying non-zero offset 140355803590656 to null pointer
    #0 elf_loader_map_phdrs drlibc/drlibc_module_elf.c:459:77
    #1 privload_map_and_relocate unix/loader.c:571:12
    #2 dr_map_executable_file lib/instrument.c:3997:12
    #3 dynamorio::drmemtrace::module_mapper_t::read_and_map_modules() clients/drcachesim/tracer/raw2trace_shared.cpp:334:21
    #4 dynamorio::drmemtrace::module_mapper_t::get_loaded_modules() drmemtrace/raw2trace_shared.h:270:13

drlibc/drlibc_module_elf.c:525:58: runtime error: applying non-zero offset 126787216 to null pointer
    #0 0x5647d0371fdb in elf_loader_map_phdrs drlibc/drlibc_module_elf.c:525:58
    #1 0x5647d034d227 in privload_map_and_relocate unix/loader.c:571:12
    #2 0x5647d032692c in dr_map_executable_file lib/instrument.c:3997:12
    #3 0x7fd41a57cb0f in dynamorio::drmemtrace::module_mapper_t::read_and_map_modules() drcachesim/tracer/raw2trace_shared.cpp:334:21
    #4 0x7fd41a57e6e2 in dynamorio::drmemtrace::module_mapper_t::get_loaded_modules() drcachesim/tracer/raw2trace_shared.h:270:13

clients/drcachesim/tracer/raw2trace_shared.h:315:82: runtime error: applying non-zero offset 3 to null pointer
    #0 dynamorio::drmemtrace::module_mapper_t::get_orig_pc clients/drcachesim/tracer/raw2trace_shared.h:315:82
    #1 dynamorio::drmemtrace::raw2trace_t::append_bb_entries clients/drcachesim/tracer/raw2trace.cpp:1540:19
    #2 dynamorio::drmemtrace::raw2trace_t::process_offline_entry clients/drcachesim/tracer/raw2trace.cpp:420:14
    #3 dynamorio::drmemtrace::raw2trace_t::process_next_thread_buffer clients/drcachesim/tracer/raw2trace.cpp:997:24

ext/drcovlib/modules.c:470:75: runtime error: applying non-zero offset 1 to null pointer
    #0 module_read_entry_print ext/drcovlib/modules.c:470:75
    #1 drmodtrack_offline_write ext/drcovlib/modules.c:838:15
    #2 dynamorio::drmemtrace::module_mapper_t::write_module_data clients/drcachesim/tracer/raw2trace_shared.cpp:249:15

clients/drcachesim/tracer/raw2trace_shared.h:289:61: runtime error: applying non-zero offset 3 to null pointer
    #0 dynamorio::drmemtrace::module_mapper_t::get_orig_pc_from_map_pc clients/drcachesim/tracer/raw2trace_shared.h:289:61
    #1 dynamorio::drmemtrace::raw2trace_t::append_bb_entries clients/drcachesim/tracer/raw2trace.cpp:1568:36
    #2 dynamorio::drmemtrace::raw2trace_t::process_offline_entry clients/drcachesim/tracer/raw2trace.cpp:420:14
    #3 dynamorio::drmemtrace::raw2trace_t::process_next_thread_buffer clients/drcachesim/tracer/raw2trace.cpp:997:24

[vitalybuka]

More reports

core/unix/module_elf.c:394:51: runtime error: applying non-zero offset 94646340419584 to null pointer
    #0 module_walk_program_headers core/unix/module_elf.c:394:51
    #1 os_module_area_init core/unix/module.c:84:9
    #2 module_area_create core/module_list.c:126:5
    #3 module_list_add core/module_list.c:260:13
    #4 os_walk_address_space core/unix/os.c:10078:17
    #5 find_executable_vm_areas core/unix/os.c:10145:13
    #6 vm_areas_init core/vmareas.c:1675:13
    #7 dynamorio_app_init_part_two_finalize core/dynamo.c:683:13
    #8 dynamorio_app_init core/dynamo.c:395:12
    #9 dr_app_setup core/dynamo.c:2745:11

core/drlibc/drlibc_module_elf.c:525:58: runtime error: applying non-zero offset 136317360 to null pointer
    #0 elf_loader_map_phdrs core/drlibc/drlibc_module_elf.c:525:58
    #1 privload_map_and_relocate core/unix/loader.c:571:12
    #2 dr_map_executable_file core/lib/instrument.c:3997:12

clients/drcachesim/tracer/output.cpp:835:85: runtime error: applying non-zero offset 4096 to null pointer
    #0 dynamorio::drmemtrace::output_buffer clients/drcachesim/tracer/output.cpp:835:85

core/unix/signal.c:5075:78: runtime error: applying non-zero offset 18446744073709551614 to null pointer
    #0 record_pending_signal core/unix/signal.c:5075:78