[PATCH 1/2] pathspec: use match for sparse-index expansion checks
- From
tnyman@openai.com <tnyman@openai.com>
- Date
- Jul 20, 2026, 22:31 UTC
- Message-ID
- <20260720223118.62821-5-tnyman@openai.com>
- In-Reply-To
- <20260720223118.62821-4-tnyman@openai.com>
From: Ted Nyman <tnyman@openai.com>
The pathspec parser computes `len` and `nowildcard_len` from `item.match`, which includes any prefix added when a command is run from a subdirectory. `item.original` can still contain the shorter, unprefixed argument.
Using `item.original + item.nowildcard_len` in `pathspec_needs_expanded_index()` can therefore read past the end of the allocation. AddressSanitizer reports a heap-buffer-overflow for prefixed wildcard pathspecs passed to `git rm` and `git reset` with a sparse index.
The mismatch dates back to 4d1cfc1351 ("reset: make --mixed sparse-aware", 2021-11-29), which introduced the helper using `item.original`. b29ad38322 ("pathspec.h: move pathspec_needs_expanded_index() from reset.c to here", 2022-08-07) later moved it to `pathspec.c` and preserved the affected comparisons.
Use `item.match` consistently when checking whether a pathspec can match a sparse-directory entry. Add coverage for prefixed wildcard pathspecs so both commands keep the index sparse.
Signed-off-by: Ted Nyman <tnyman@openai.com> --- pathspec.c | 12 ++++++------ t/t1092-sparse-checkout-compatibility.sh | 7 +++++++ 2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/pathspec.c b/pathspec.c index f78b22709ccb67..281858f21f9c59 100644 --- a/pathspec.c +++ b/pathspec.c @@ -847,9 +847,9 @@ int pathspec_needs_expanded_index(struct index_state *istate, * - not-in-cone/bar*: may need expanded index * - **.c: may need expanded index */ - if (strspn(item.original + item.nowildcard_len, "*") == + if (strspn(item.match + item.nowildcard_len, "*") == (unsigned int)(item.len - item.nowildcard_len) && - path_in_cone_mode_sparse_checkout(item.original, istate)) + path_in_cone_mode_sparse_checkout(item.match, istate)) continue; for (pos = 0; pos < istate->cache_nr; pos++) { @@ -865,7 +865,7 @@ int pathspec_needs_expanded_index(struct index_state *istate, */ if ((unsigned int)item.nowildcard_len > ce_namelen(ce) && - !strncmp(item.original, ce->name, + !strncmp(item.match, ce->name, ce_namelen(ce))) { res = 1; break; @@ -876,13 +876,13 @@ int pathspec_needs_expanded_index(struct index_state *istate, * directory and the pathspec does not match the whole * directory, need to expand the index. */ - if (!strncmp(item.original, ce->name, item.nowildcard_len) && - wildmatch(item.original, ce->name, 0)) { + if (!strncmp(item.match, ce->name, item.nowildcard_len) && + wildmatch(item.match, ce->name, 0)) { res = 1; break; } } - } else if (!path_in_cone_mode_sparse_checkout(item.original, istate) && + } else if (!path_in_cone_mode_sparse_checkout(item.match, istate) && !matches_skip_worktree(pathspec, i, &skip_worktree_seen)) res = 1; diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh index 9814431cd74aff..d0b42371663f9d 100755 --- a/t/t1092-sparse-checkout-compatibility.sh +++ b/t/t1092-sparse-checkout-compatibility.sh @@ -2119,6 +2119,13 @@ test_expect_success 'sparse index is not expanded: rm' ' ensure_not_expanded rm -r deep ' +test_expect_success 'sparse index is not expanded: prefixed wildcard pathspec' ' + init_repos && + + ensure_not_expanded -C deep rm --dry-run -- "a*" && + ensure_not_expanded -C deep reset base -- "a*" +' + test_expect_success 'grep with and --cached' ' init_repos &&