freshlybakedca.ke / git
Git fork
fork atom

userdiff: fix leaking memory for configured diff drivers

The userdiff structures may be initialized either statically on the
stack or dynamically via configuration keys. In the latter case we end
up leaking memory because we didn't have any infrastructure to discern
those strings which have been allocated statically and those which have
been allocated dynamically.

Refactor the code such that we have two pointers for each of these
strings: one that holds the value as accessed by other subsystems, and
one that points to the same string in case it has been allocated. Like
this, we can safely free the second pointer and thus plug those memory
leaks.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

authored by

Patrick Steinhardt and committed by
Junio C Hamano 38678e5d 1bc158e7

+43 -11
unified split
+4 -2
range-diff.c
··· 450 450 } 451 451 452 452 static struct userdiff_driver section_headers = { 453 - .funcname = { "^ ## (.*) ##$\n" 454 - "^.?@@ (.*)$", REG_EXTENDED } 453 + .funcname = { 454 + .pattern = "^ ## (.*) ##$\n^.?@@ (.*)$", 455 + .cflags = REG_EXTENDED, 456 + }, 455 457 }; 456 458 457 459 static struct diff_filespec *get_filespec(const char *name, const char *p)
+1
t/t4018-diff-funcname.sh
··· 5 5 6 6 test_description='Test custom diff function name patterns' 7 7 8 + TEST_PASSES_SANITIZE_LEAK=true 8 9 . ./test-lib.sh 9 10 10 11 test_expect_success 'setup' '
+2
t/t4042-diff-textconv-caching.sh
··· 1 1 #!/bin/sh 2 2 3 3 test_description='test textconv caching' 4 + 5 + TEST_PASSES_SANITIZE_LEAK=true 4 6 . ./test-lib.sh 5 7 6 8 cat >helper <<'EOF'
+1
t/t4048-diff-combined-binary.sh
··· 4 4 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main 5 5 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME 6 6 7 + TEST_PASSES_SANITIZE_LEAK=true 7 8 . ./test-lib.sh 8 9 9 10 test_expect_success 'setup binary merge conflict' '
+2
t/t4209-log-pickaxe.sh
··· 1 1 #!/bin/sh 2 2 3 3 test_description='log --grep/--author/--regexp-ignore-case/-S/-G' 4 + 5 + TEST_PASSES_SANITIZE_LEAK=true 4 6 . ./test-lib.sh 5 7 6 8 test_log () {
+29 -9
userdiff.c
··· 399 399 static int parse_funcname(struct userdiff_funcname *f, const char *k, 400 400 const char *v, int cflags) 401 401 { 402 - if (git_config_string((char **) &f->pattern, k, v) < 0) 402 + f->pattern = NULL; 403 + FREE_AND_NULL(f->pattern_owned); 404 + if (git_config_string(&f->pattern_owned, k, v) < 0) 403 405 return -1; 406 + f->pattern = f->pattern_owned; 404 407 f->cflags = cflags; 405 408 return 0; 406 409 } ··· 444 447 return parse_funcname(&drv->funcname, k, v, REG_EXTENDED); 445 448 if (!strcmp(type, "binary")) 446 449 return parse_tristate(&drv->binary, k, v); 447 - if (!strcmp(type, "command")) 448 - return git_config_string((char **) &drv->external.cmd, k, v); 450 + if (!strcmp(type, "command")) { 451 + FREE_AND_NULL(drv->external.cmd); 452 + return git_config_string(&drv->external.cmd, k, v); 453 + } 449 454 if (!strcmp(type, "trustexitcode")) { 450 455 drv->external.trust_exit_code = git_config_bool(k, v); 451 456 return 0; 452 457 } 453 - if (!strcmp(type, "textconv")) 454 - return git_config_string((char **) &drv->textconv, k, v); 458 + if (!strcmp(type, "textconv")) { 459 + int ret; 460 + FREE_AND_NULL(drv->textconv_owned); 461 + ret = git_config_string(&drv->textconv_owned, k, v); 462 + drv->textconv = drv->textconv_owned; 463 + return ret; 464 + } 455 465 if (!strcmp(type, "cachetextconv")) 456 466 return parse_bool(&drv->textconv_want_cache, k, v); 457 - if (!strcmp(type, "wordregex")) 458 - return git_config_string((char **) &drv->word_regex, k, v); 459 - if (!strcmp(type, "algorithm")) 460 - return git_config_string((char **) &drv->algorithm, k, v); 467 + if (!strcmp(type, "wordregex")) { 468 + int ret; 469 + FREE_AND_NULL(drv->word_regex_owned); 470 + ret = git_config_string(&drv->word_regex_owned, k, v); 471 + drv->word_regex = drv->word_regex_owned; 472 + return ret; 473 + } 474 + if (!strcmp(type, "algorithm")) { 475 + int ret; 476 + FREE_AND_NULL(drv->algorithm_owned); 477 + ret = git_config_string(&drv->algorithm_owned, k, v); 478 + drv->algorithm = drv->algorithm_owned; 479 + return ret; 480 + } 461 481 462 482 return 0; 463 483 }
+4
userdiff.h
··· 8 8 9 9 struct userdiff_funcname { 10 10 const char *pattern; 11 + char *pattern_owned; 11 12 int cflags; 12 13 }; 13 14 ··· 20 21 const char *name; 21 22 struct external_diff external; 22 23 const char *algorithm; 24 + char *algorithm_owned; 23 25 int binary; 24 26 struct userdiff_funcname funcname; 25 27 const char *word_regex; 28 + char *word_regex_owned; 26 29 const char *word_regex_multi_byte; 27 30 const char *textconv; 31 + char *textconv_owned; 28 32 struct notes_cache *textconv_cache; 29 33 int textconv_want_cache; 30 34 };