Possible memory leak bug reports for the latest "git" repository.

Dear Git Development team.

Hi. Recently, we discovered that the vulnerable code of CVE-2019-9169 is included in the latest version (v2.31.1) of your source repository (https://github.com/git/git).

Vulnerable file: git/compat/regex/regexec.c

Ref: CVE-2019-9169 (https://nvd.nist.gov/vuln/detail/CVE-2019-9169)

Original patch link: https://sourceware.org/git/?p=glibc.git;a=blobdiff;f=posix/regexec.c;h=084b1222d95b62eb2930166060174ef78cb74b02;hp=91d5a797b82e2679ceab74238416de06693e46ea;hb=583dd860d5b833037175247230a328f0050dbfe9;hpb=2bac7daa58da1a313bd452369b0508b31e146637

Although the original vulnerability caused a heap-based buffer over-read, the vulnerable code seems to cause a memory leak in your repository.

Could you review whether this is a real vulnerability?

The below information shows our testing environments and results:

***************************************************************************************** First test:

OS: Ubuntu 16.04.07 LTS
Git version: v2.31.1
Makefile config:

  1184 # Set CFLAGS, LDFLAGS and other *FLAGS variables. These might be
  1185 # tweaked by config.* below as well as the command-line, both of
  1186 # which'll override these defaults.
  1187 CFLAGS = -g -O2 -Wall -fsanitize=address
  1188 LDFLAGS =

Result:

$ ./git-log -i '\(\(\)*.\)*\(\)\(\)\1' fatal: your current branch 'master' does not have any commits yet ================================================================= ==27253==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 65 byte(s) in 1 object(s) allocated from:
    #0 0x7f6ff01de961 in realloc
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98961)
    #1 0x843ee5 in xrealloc  /HDD/POC/CVE-2019-9169/git-2.31.1/wrapper.c:126

SUMMARY: AddressSanitizer: 65 byte(s) leaked in 1 allocation(s).
*****************************************************************************************

***************************************************************************************** Second test:

OS: Ubuntu 18.04.5 LTS
Git version: v2.31.1
Makefile config: Default

Result:

$ printf xxxxxxxxxxxxxx |valgrind --leak-check=full ./git-log -i '\(\(\)*.\)*\1' ==63105== Memcheck, a memory error detector ==63105== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==63105== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info ==63105== Command: ./git-log -i \\(\\(\\)*.\\)*\\1 ==63105== ==63105== ==63105== HEAP SUMMARY: ==63105== in use at exit: 118,368,930 bytes in 76,720 blocks ==63105== total heap usage: 463,994 allocs, 387,274 frees, 2,273,364,625 bytes allocated ==63105== ==63105== 40 bytes in 1 blocks are possibly lost in loss record 38 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x355BB5: chdir_notify_register (chdir-notify.c:18) ==63105== by 0x355BB5: chdir_notify_reparent (chdir-notify.c:48) ==63105== by 0x2D5DC6: packed_ref_store_create (packed-backend.c:207) ==63105== by 0x2D02BA: files_ref_store_create (files-backend.c:96) ==63105== by 0x2CC295: get_main_ref_store (refs.c:1900) ==63105== by 0x2E969D: handle_revision_pseudo_opt (revision.c:2578) ==63105== by 0x2E969D: setup_revisions (revision.c:2730) ==63105== by 0x180562: cmd_log_init_finish (log.c:206) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 40 bytes in 1 blocks are possibly lost in loss record 39 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x355BB5: chdir_notify_register (chdir-notify.c:18) ==63105== by 0x355BB5: chdir_notify_reparent (chdir-notify.c:48) ==63105== by 0x2D02D6: files_ref_store_create (files-backend.c:99) ==63105== by 0x2CC295: get_main_ref_store (refs.c:1900) ==63105== by 0x2E969D: handle_revision_pseudo_opt (revision.c:2578) ==63105== by 0x2E969D: setup_revisions (revision.c:2730) ==63105== by 0x180562: cmd_log_init_finish (log.c:206) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 40 bytes in 1 blocks are possibly lost in loss record 40 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x355BB5: chdir_notify_register (chdir-notify.c:18) ==63105== by 0x355BB5: chdir_notify_reparent (chdir-notify.c:48) ==63105== by 0x2D02E6: files_ref_store_create (files-backend.c:100) ==63105== by 0x2CC295: get_main_ref_store (refs.c:1900) ==63105== by 0x2E969D: handle_revision_pseudo_opt (revision.c:2578) ==63105== by 0x2E969D: setup_revisions (revision.c:2730) ==63105== by 0x180562: cmd_log_init_finish (log.c:206) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 65 bytes in 1 blocks are definitely lost in loss record 59 of 142 ==63105== at 0x4C31A3F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x4C33D84: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x340345: xrealloc (wrapper.c:126) ==63105== by 0x30B93A: strbuf_grow (strbuf.c:98) ==63105== by 0x30C8EC: strbuf_vaddf (strbuf.c:392) ==63105== by 0x30CA33: strbuf_addf (strbuf.c:333) ==63105== by 0x2A9700: preprocess_options (parse-options.c:666) ==63105== by 0x2A9700: parse_options (parse-options.c:847) ==63105== by 0x18053E: cmd_log_init_finish (log.c:199) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 84 (56 direct, 28 indirect) bytes in 1 blocks are definitely lost in loss record 61 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x2AE9C0: copy_pathspec (pathspec.c:664) ==63105== by 0x2E993A: setup_revisions (revision.c:2844) ==63105== by 0x180562: cmd_log_init_finish (log.c:206) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 84 (56 direct, 28 indirect) bytes in 1 blocks are definitely lost in loss record 62 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x2AE9C0: copy_pathspec (pathspec.c:664) ==63105== by 0x2E996A: setup_revisions (revision.c:2849) ==63105== by 0x180562: cmd_log_init_finish (log.c:206) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 191 (112 direct, 79 indirect) bytes in 1 blocks are definitely lost in loss record 76 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x2AE381: parse_pathspec (pathspec.c:582) ==63105== by 0x2E9164: setup_revisions (revision.c:2800) ==63105== by 0x180562: cmd_log_init_finish (log.c:206) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 464 (448 direct, 16 indirect) bytes in 28 blocks are definitely lost in loss record 98 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x217A3D: commit_list_insert (commit.c:554) ==63105== by 0x217A3D: parse_commit_buffer (commit.c:447) ==63105== by 0x296F37: parse_object_buffer (object.c:217) ==63105== by 0x297070: parse_object (object.c:282) ==63105== by 0x274781: add_ref_decoration (log-tree.c:179) ==63105== by 0x2D5C53: do_for_each_repo_ref_iterator (iterator.c:418) ==63105== by 0x2CB9F8: do_for_each_ref (refs.c:1492) ==63105== by 0x274A65: load_ref_decorations (log-tree.c:211) ==63105== by 0x1807C9: cmd_log_init_finish (log.c:262) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== ==63105== 37,468 (32 direct, 37,436 indirect) bytes in 1 blocks are definitely lost in loss record 120 of 142 ==63105== at 0x4C33B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x3403AD: xcalloc (wrapper.c:140) ==63105== by 0x1806F4: cmd_log_init_finish (log.c:233) ==63105== by 0x18241F: cmd_log_init (log.c:275) ==63105== by 0x18241F: cmd_log (log.c:754) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== by 0x1289A4: cmd_main (git.c:872) ==63105== by 0x127467: main (common-main.c:52) ==63105== ==63105== 184,176 (183,792 direct, 384 indirect) bytes in 11,487 blocks are definitely lost in loss record 130 of 142 ==63105== at 0x4C31B0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==63105== by 0x34013A: do_xmalloc (wrapper.c:41) ==63105== by 0x217A3D: commit_list_insert (commit.c:554) ==63105== by 0x217A3D: parse_commit_buffer (commit.c:447) ==63105== by 0x217CEC: repo_parse_commit_internal (commit.c:498) ==63105== by 0x2E4C3D: repo_parse_commit (commit.h:89) ==63105== by 0x2E4C3D: try_to_simplify_commit (revision.c:1007) ==63105== by 0x2E84AA: process_parents (revision.c:1140) ==63105== by 0x2EBFED: get_revision_1 (revision.c:3999) ==63105== by 0x2EC1BF: get_revision_internal (revision.c:4113) ==63105== by 0x2EC344: get_revision (revision.c:4187) ==63105== by 0x181538: cmd_log_walk (log.c:422) ==63105== by 0x182427: cmd_log (log.c:755) ==63105== by 0x12781D: run_builtin (git.c:453) ==63105== by 0x12781D: handle_builtin (git.c:704) ==63105== ==63105== LEAK SUMMARY: ==63105== definitely lost: 184,561 bytes in 11,520 blocks ==63105== indirectly lost: 37,971 bytes in 1,139 blocks ==63105== possibly lost: 120 bytes in 3 blocks ==63105== still reachable: 118,146,278 bytes in 64,058 blocks ==63105== suppressed: 0 bytes in 0 blocks ==63105== Reachable blocks (those to which a pointer was found) are not shown. ==63105== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==63105== ==63105== For counts of detected and suppressed errors, rerun with: -v ==63105== ERROR SUMMARY: 10 errors from 10 contexts (suppressed: 0 from 0) *****************************************************************************************

Thank you. Best regards, Seunghoon Woo, Jiyeon Han