From 64cc539fd2f8e02f39cfae21e9523da2532c0467 Mon Sep 17 00:00:00 2001 From: Andrzej Hunt Date: Sun, 21 Mar 2021 16:58:36 +0000 Subject: [PATCH] parse-options: don't leak alias help messages preprocess_options() allocates new strings for help messages for OPTION_ALIAS. Therefore we also need to clean those help messages up when freeing the returned options. First introduced in: 7c280589cf (parse-options: teach "git cmd -h" to show alias as alias, 2020-03-16) The preprocessed options themselves no longer contain any indication that a given option is/was an alias - therefore we add a new flag to indicate former aliases. (An alternative approach would be to look back at the original options to determine which options are aliases - but that seems like a fragile approach. Or we could even look at the alias_groups list - which might be less fragile, but would be slower as it requires nested looping.) As far as I can tell, parse_options() is only ever used once per command, and the help messages are small - hence this leak has very little impact. This leak was found while running t0001. LSAN output can be found below: Direct leak of 65 byte(s) in 1 object(s) allocated from: #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9aae36 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8 #2 0x939d8d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2 #3 0x93b936 in strbuf_vaddf /home/ahunt/oss-fuzz/git/strbuf.c:392:3 #4 0x93b7ff in strbuf_addf /home/ahunt/oss-fuzz/git/strbuf.c:333:2 #5 0x86747e in preprocess_options /home/ahunt/oss-fuzz/git/parse-options.c:666:3 #6 0x866ed2 in parse_options /home/ahunt/oss-fuzz/git/parse-options.c:847:17 #7 0x51c4a7 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:989:9 #8 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #9 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #10 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #11 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #12 0x69c9fe in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #13 0x7fdac42d4349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt Signed-off-by: Junio C Hamano --- parse-options.c | 19 ++++++++++++++++++- parse-options.h | 1 + 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/parse-options.c b/parse-options.c index fbea16eaf5..e6f56768ca 100644 --- a/parse-options.c +++ b/parse-options.c @@ -625,6 +625,8 @@ static int show_gitcomp(const struct option *opts, int show_all) * * Right now this is only used to preprocess and substitute * OPTION_ALIAS. + * + * The returned options should be freed using free_preprocessed_options. */ static struct option *preprocess_options(struct parse_opt_ctx_t *ctx, const struct option *options) @@ -678,6 +680,7 @@ static struct option *preprocess_options(struct parse_opt_ctx_t *ctx, newopt[i].short_name = short_name; newopt[i].long_name = long_name; newopt[i].help = strbuf_detach(&help, NULL); + newopt[i].flags |= PARSE_OPT_FROM_ALIAS; break; } @@ -693,6 +696,20 @@ static struct option *preprocess_options(struct parse_opt_ctx_t *ctx, return newopt; } +static void free_preprocessed_options(struct option *options) +{ + int i; + + if (!options) + return; + + for (i = 0; options[i].type != OPTION_END; i++) { + if (options[i].flags & PARSE_OPT_FROM_ALIAS) + free((void *)options[i].help); + } + free(options); +} + static int usage_with_options_internal(struct parse_opt_ctx_t *, const char * const *, const struct option *, int, int); @@ -870,7 +887,7 @@ int parse_options(int argc, const char **argv, const char *prefix, } precompose_argv_prefix(argc, argv, NULL); - free(real_options); + free_preprocessed_options(real_options); free(ctx.alias_groups); return parse_options_end(&ctx); } diff --git a/parse-options.h b/parse-options.h index f2ddef18f7..a845a9d952 100644 --- a/parse-options.h +++ b/parse-options.h @@ -44,6 +44,7 @@ enum parse_opt_option_flags { PARSE_OPT_LASTARG_DEFAULT = 1 << 4, PARSE_OPT_NODASH = 1 << 5, PARSE_OPT_LITERAL_ARGHELP = 1 << 6, + PARSE_OPT_FROM_ALIAS = 1 << 7, PARSE_OPT_SHELL_EVAL = 1 << 8, PARSE_OPT_NOCOMPLETE = 1 << 9, PARSE_OPT_COMP_ARG = 1 << 10,