harden wf_cliprdr.c (#15515)

* harden wf_cliprdr.c

* fix copilot review

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* fix review

* fix review

* condense hardening comments, fix style in wf_cliprdr.c

Comment-only cleanup of the review-justification comments; also move
the mutex wait result declaration to the top of the block and fix
continuation-line indentation. No behavior change.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* add invariant tests for file contents request/response hardening

Cover the zeroed optional request fields, stream ID filtering,
oversized/NULL response rejection and the zero-byte EOF path.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* address copilot review findings in wf_cliprdr.c

- Reject a negative FILECONTENTS_SIZE result: m_lSize is unsigned, so a
  negative value became a huge bogus stream size that keeps reads going.
- Use a unique per-stream counter as the CLIPRDR streamId instead of a
  truncated IStream pointer, which could collide or be reused after free
  (and leaked heap addresses to the peer).
- Add req_f_request_mutex to serialize whole file-contents request/response
  cycles, enforcing the previously assumed one-outstanding-request
  invariant when multiple streams are read concurrently. Bounded acquire
  so a wedged request fails the read instead of hanging a consumer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* serialize file-contents request state and poison streams after timeout

- Extract lock_mutex() for the WAIT_OBJECT_0/WAIT_ABANDONED idiom shared by
  take_req_fdata, the request-serialization acquire, and the response handler.
- Collapse the acquire/send/take/release cycle into
  cliprdr_request_filecontents_sync(), used by CliprdrStream_Read and the size
  probe in CliprdrStream_New.
- Publish req_f_stream_id_expected/req_f_size_requested under req_f_mutex in the
  sender and read them under the same lock in the response handler, removing the
  cross-thread data race on those fields.
- Poison a stream (m_failed) after a request fails/times out, so a late response
  carrying a previous offset's bytes cannot satisfy a later same-stream read.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* key the responder stream cache on connID as well as streamId

Per-stream ids restart from 1 in each peer process, so two connections can
emit the same streamId. The process-static pStreamStc cache keyed only on
streamId could then serve one peer the IStream cached for another peer (a
different file), silently returning wrong-file bytes. Add connID to the key.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* harden the format-data path against late/duplicate responses

The format-data rendezvous had the same single-slot race the file-contents
path just fixed: the channel thread rewrote clipboard->hmem with no lock while
explorer-thread consumers read/freed it, nothing serialized concurrent
requests, and no flag told an expected response from a stray one.

- Add format_request_mutex (serializes the whole request/response cycle) and
  hmem_mutex (guards the hmem hand-off and formatDataRespExpected).
- cliprdr_send_data_request now takes ownership of the response buffer under
  hmem_mutex and returns it to the caller, so a later response cannot touch a
  buffer a consumer is using. All three consumers (GetData, WM_RENDERFORMAT,
  DELAYED_RENDERING) and the WM_CLIPBOARDUPDATE cleanup use the returned/taken
  handle instead of the shared slot.
- The response handler drops any response arriving while formatDataRespExpected
  is clear (late/duplicate/unsolicited), consumes the flag on the first
  response, and no longer dereferences a NULL clipboard in the SetEvent path.

Pre-existing issue, not introduced by this branch; generalizes the
file-contents hardening to the format-data path.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* remove the dedicated wf-cliprdr CI workflow

Drop .github/workflows/wf-cliprdr-ci.yml on this branch as requested.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* remove wf-cliprdr invariant tests

Drop tests/test_invariant_wf_cliprdr.c on this branch as requested.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* refactor and simplify, remove mutex which is dangeours

* fix copilot false report

* fix review

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

tests/test_invariant_wf_cliprdr.c

@@ -1,92 +0,0 @@
-#include <check.h>
-#include <stdlib.h>
-#include <stddef.h>
-
-#include "../libs/clipboard/src/windows/wf_cliprdr.c"
-
-static SIZE_T descriptor_size(UINT count)
-{
-	return offsetof(FILEGROUPDESCRIPTORW, fgd) + (SIZE_T)count * sizeof(FILEDESCRIPTORW);
-}
-
-START_TEST(test_descriptor_size_rejects_buffer_smaller_than_header)
-{
-	ck_assert_int_eq(wf_cliprdr_file_group_descriptor_size_valid(0, 1), FALSE);
-	ck_assert_int_eq(wf_cliprdr_file_group_descriptor_size_valid(
-	                     offsetof(FILEGROUPDESCRIPTORW, fgd) - 1, 1),
-	                 FALSE);
-}
-END_TEST
-
-START_TEST(test_descriptor_size_rejects_zero_items)
-{
-	ck_assert_int_eq(
-	    wf_cliprdr_file_group_descriptor_size_valid(offsetof(FILEGROUPDESCRIPTORW, fgd), 0),
-	    FALSE);
-}
-END_TEST
-
-START_TEST(test_descriptor_size_accepts_max_stream_count)
-{
-	ck_assert_int_eq(wf_cliprdr_file_group_descriptor_size_valid(
-	                     descriptor_size(WF_CLIPRDR_MAX_STREAMS), WF_CLIPRDR_MAX_STREAMS),
-	                 TRUE);
-}
-END_TEST
-
-START_TEST(test_descriptor_size_rejects_stream_count_above_limit)
-{
-	ck_assert_int_eq(wf_cliprdr_file_group_descriptor_size_valid(
-	                     descriptor_size(WF_CLIPRDR_MAX_STREAMS), WF_CLIPRDR_MAX_STREAMS + 1),
-	                 FALSE);
-}
-END_TEST
-
-START_TEST(test_descriptor_size_rejects_truncated_descriptor_array)
-{
-	ck_assert_int_eq(wf_cliprdr_file_group_descriptor_size_valid(descriptor_size(2) - 1, 2),
-	                 FALSE);
-}
-END_TEST
-
-START_TEST(test_descriptor_size_rejects_extreme_count)
-{
-	ck_assert_int_eq(wf_cliprdr_file_group_descriptor_size_valid((SIZE_T)-1, (UINT)-1),
-	                 FALSE);
-}
-END_TEST
-
-Suite *wf_cliprdr_invariant_suite(void)
-{
-	Suite *s;
-	TCase *tc_core;
-
-	s = suite_create("wf_cliprdr_invariants");
-	tc_core = tcase_create("descriptor_size");
-
-	tcase_add_test(tc_core, test_descriptor_size_rejects_buffer_smaller_than_header);
-	tcase_add_test(tc_core, test_descriptor_size_rejects_zero_items);
-	tcase_add_test(tc_core, test_descriptor_size_accepts_max_stream_count);
-	tcase_add_test(tc_core, test_descriptor_size_rejects_stream_count_above_limit);
-	tcase_add_test(tc_core, test_descriptor_size_rejects_truncated_descriptor_array);
-	tcase_add_test(tc_core, test_descriptor_size_rejects_extreme_count);
-
-	suite_add_tcase(s, tc_core);
-	return s;
-}
-
-int main(void)
-{
-	int number_failed;
-	Suite *s;
-	SRunner *sr;
-
-	s = wf_cliprdr_invariant_suite();
-	sr = srunner_create(s);
-
-	srunner_run_all(sr, CK_NORMAL);
-	number_failed = srunner_ntests_failed(sr);
-	srunner_free(sr);
-
-	return (number_failed == 0) ? EXIT_SUCCESS : EXIT_FAILURE;
-}