[PATCH 13/23] diffcore-order: fix leaking buffer when parsing orderfiles
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Sep 16, 2024, 11:46 UTC
- Message-ID
- <c975dfe462e321252bd4c83f4ed18bc7757204b7.1726484308.git.ps@pks.im>
- In-Reply-To
- <cover.1726484308.git.ps@pks.im>
In `prepare_order()` we parse an orderfile and assign it to a global array. In order to save on some allocations, we replace newlines with NUL characters and then assign pointers into the allocated buffer to that array. This can cause the buffer to be completely unreferenced though in some cases, e.g. because the order file is empty or because we had to use `xmemdupz()` to copy the lines instead of NUL-terminating them.
Refactor the code to always `xmemdupz()` the strings. This is a bit simpler, and it is rather unlikely that saving a handful of allocations really matters. This allows us to release the string buffer and thus plug the memory leak.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- diffcore-order.c | 19 +++++++------------ t/t4056-diff-order.sh | 1 + t/t4204-patch-id.sh | 1 + 3 files changed, 9 insertions(+), 12 deletions(-)
diff --git a/diffcore-order.c b/diffcore-order.c index e7d20ebd2d1..912513d3e67 100644 --- a/diffcore-order.c +++ b/diffcore-order.c @@ -14,8 +14,7 @@ static void prepare_order(const char *orderfile) { int cnt, pass; struct strbuf sb = STRBUF_INIT; - void *map; - char *cp, *endp; + const char *cp, *endp; ssize_t sz; if (order) @@ -24,14 +23,13 @@ static void prepare_order(const char *orderfile) sz = strbuf_read_file(&sb, orderfile, 0); if (sz < 0) die_errno(_("failed to read orderfile '%s'"), orderfile); - map = strbuf_detach(&sb, NULL); - endp = (char *) map + sz; + endp = sb.buf + sz; for (pass = 0; pass < 2; pass++) { cnt = 0; - cp = map; + cp = sb.buf; while (cp < endp) { - char *ep; + const char *ep; for (ep = cp; ep < endp && *ep != '\n'; ep++) ; /* cp to ep has one line */ @@ -40,12 +38,7 @@ static void prepare_order(const char *orderfile) else if (pass == 0) cnt++; else { - if (*ep == '\n') { - *ep = 0; - order[cnt] = cp; - } else { - order[cnt] = xmemdupz(cp, ep - cp); - } + order[cnt] = xmemdupz(cp, ep - cp); cnt++; } if (ep < endp) @@ -57,6 +50,8 @@ static void prepare_order(const char *orderfile) ALLOC_ARRAY(order, cnt); } } + + strbuf_release(&sb); } static int match_order(const char *path) diff --git a/t/t4056-diff-order.sh b/t/t4056-diff-order.sh index aec1d9d1b42..32c5fcb9a27 100755 --- a/t/t4056-diff-order.sh +++ b/t/t4056-diff-order.sh @@ -5,6 +5,7 @@ test_description='diff order & rotate' GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME +TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh create_files () { diff --git a/t/t4204-patch-id.sh b/t/t4204-patch-id.sh index dc8ddb10aff..c0a4a02dcfa 100755 --- a/t/t4204-patch-id.sh +++ b/t/t4204-patch-id.sh @@ -5,6 +5,7 @@ test_description='git patch-id' GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME +TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh test_expect_success 'setup' '
-- 2.46.0.551.gc5ee8f2d1c.dirty