The branch main has been updated by asomers: URL: https://cgit.FreeBSD.org/src/commit/?id=74bd6fb1eb028d15df407efb62628253dab90aa5
commit 74bd6fb1eb028d15df407efb62628253dab90aa5 Author: Jitendra Bhati <[email protected]> AuthorDate: 2026-08-04 19:40:32 +0000 Commit: Alan Somers <[email protected]> CommitDate: 2026-08-06 22:51:25 +0000 fts: fix fts_accpath regression after fts_children() When fts_children() is called, sp->fts_child is set. On the next fts_read() call, fts_safe_changedir() was incorrectly passed p->fts_dirfd (pointing to the parent directory) instead of -1. This caused fts to fchdir to the parent instead of the child directory, silently skipping the contents of 3rd-level subdirectories. This was observed as a failure in nmtree_test:mtree_create which calls fts_children() internally. Add regression test accpath_correct_after_descent that calls fts_children() on each directory entry and verifies files at depth 3 are still visited correctly. The test fails with the unfixed libc and passes with the fix. Reported by: Herbert J. Skuhra <[email protected]> Sponsored by: Google LLC (GSoC 2026) Reviewed by: asomers Fixes: 4bd01d6ae01 ("fts: refactor to use fd-relative") Pull Request: https://github.com/freebsd/freebsd-src/pull/2354 --- lib/libc/gen/fts.c | 3 +- lib/libc/tests/gen/fts_regress_test.c | 60 +++++++++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+), 2 deletions(-) diff --git a/lib/libc/gen/fts.c b/lib/libc/gen/fts.c index 204340e4b87f..5f56d169e076 100644 --- a/lib/libc/gen/fts.c +++ b/lib/libc/gen/fts.c @@ -489,8 +489,7 @@ fts_read(FTS *sp) * FTS_STOP or the fts_info field of the node. */ if (sp->fts_child != NULL) { - if (fts_safe_changedir(sp, p, - p->fts_dirfd, p->fts_name)) { + if (fts_safe_changedir(sp, p, -1, p->fts_name)) { p->fts_errno = errno; p->fts_flags |= FTS_DONTCHDIR; for (p = sp->fts_child; p != NULL; diff --git a/lib/libc/tests/gen/fts_regress_test.c b/lib/libc/tests/gen/fts_regress_test.c index cf4035a65259..7075addf92b4 100644 --- a/lib/libc/tests/gen/fts_regress_test.c +++ b/lib/libc/tests/gen/fts_regress_test.c @@ -303,6 +303,65 @@ ATF_TC_BODY(concurrent_modification, tc) pthread_join(thr, NULL); } +/* + * Regression test for a bug introduced in 4bd01d6ae01. + * With the bug, fts fchdir'd to the parent directory instead of the child, + * causing the contents of subdirectories at depth 3 to be silently skipped. + * + */ +ATF_TC(accpath_correct_after_descent); +ATF_TC_HEAD(accpath_correct_after_descent, tc) +{ + atf_tc_set_md_var(tc, "descr", + "fts correctly descends into 3-level directory trees"); +} + +ATF_TC_BODY(accpath_correct_after_descent, tc) +{ + char *paths[] = { ".", NULL }; + FTS *fts; + FTSENT *ent, *children; + bool saw_deep_file = false; + + /* + * Create a 3-level directory tree, mirroring the structure used + * by nmtree_test:mtree_create which also triggered this bug. + */ + ATF_REQUIRE_EQ(0, mkdir("a", 0755)); + ATF_REQUIRE_EQ(0, mkdir("a/1", 0755)); + ATF_REQUIRE_EQ(0, mkdir("a/2", 0755)); + ATF_REQUIRE_EQ(0, mkdir("b", 0755)); + ATF_REQUIRE_EQ(0, close(creat("a/1/file", 0644))); + + ATF_REQUIRE((fts = fts_open(paths, FTS_PHYSICAL, NULL)) != NULL); + + while ((ent = fts_read(fts)) != NULL) { + if (ent->fts_info == FTS_D) { + /* + * Call fts_children() to set sp->fts_child. + * This triggered the bug — when fts_read() then + * descends into the directory, it calls + * fts_safe_changedir(sp, p, p->fts_dirfd, p->fts_name) + * instead of fts_safe_changedir(sp, p, -1, p->fts_name). + * With fts_dirfd pointing to the parent, it fchdir's + * to the wrong directory and contents are skipped. + */ + children = fts_children(fts, 0); + (void)children; + } + + if (strcmp(ent->fts_name, "file") == 0 && + ent->fts_info == FTS_F) + saw_deep_file = true; + } + + ATF_CHECK_MSG(saw_deep_file, + "did not visit 'a/1/file' at depth 3 — " + "fts_safe_changedir used wrong fd after fts_children()"); + + ATF_REQUIRE_EQ_MSG(0, fts_close(fts), "fts_close(): %m"); +} + ATF_TP_ADD_TCS(tp) { ATF_TP_ADD_TC(tp, read_no_exec_dir); @@ -310,6 +369,7 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, readdir_error_detected); ATF_TP_ADD_TC(tp, odirectory_changedir); ATF_TP_ADD_TC(tp, concurrent_modification); + ATF_TP_ADD_TC(tp, accpath_correct_after_descent); return (atf_no_error()); }
