From 6f3f6c506cdaf981a4374f1f12863b98ac7fea1a Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Sat, 21 Sep 2024 19:32:34 +0200 Subject: [PATCH] Linux: readdir64_r should not skip d_ino == 0 entries (bug 32126) This is the same bug as bug 12165, but for readdir_r. The regression test covers both bug 12165 and bug 32126. Reviewed-by: DJ Delorie --- dirent/Makefile | 1 + dirent/tst-readdir-zero-inode.c | 134 ++++++++++++++++++++++++++ sysdeps/unix/sysv/linux/readdir64_r.c | 29 +++--- 3 files changed, 147 insertions(+), 17 deletions(-) create mode 100644 dirent/tst-readdir-zero-inode.c diff --git a/dirent/Makefile b/dirent/Makefile index 045c786575..11b772e3ab 100644 --- a/dirent/Makefile +++ b/dirent/Makefile @@ -62,6 +62,7 @@ tests := \ tst-fdopendir \ tst-fdopendir2 \ tst-readdir-long \ + tst-readdir-zero-inode \ tst-rewinddir \ tst-scandir \ tst-scandir64 \ diff --git a/dirent/tst-readdir-zero-inode.c b/dirent/tst-readdir-zero-inode.c new file mode 100644 index 0000000000..af9fb946ab --- /dev/null +++ b/dirent/tst-readdir-zero-inode.c @@ -0,0 +1,134 @@ +/* Test that readdir does not skip entries with d_ino == 0 (bug 12165). + Copyright (C) 2024 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + +/* Add the directory entry at OFFSET to the stream D. */ +static uint64_t +add_directory_entry (struct support_fuse_dirstream *d, uint64_t offset) +{ + bool added = false; + ++offset; + switch (offset - 1) + { + case 0: + added = support_fuse_dirstream_add (d, 1, offset, DT_DIR, "."); + break; + case 1: + added = support_fuse_dirstream_add (d, 1, offset, DT_DIR, ".."); + break; + case 2: + added = support_fuse_dirstream_add (d, 2, offset, DT_REG, "before"); + break; + case 3: + added = support_fuse_dirstream_add (d, 0, offset, DT_REG, "zero"); + break; + case 4: + added = support_fuse_dirstream_add (d, 3, offset, DT_REG, "after"); + break; + } + if (added) + return offset; + else + return 0; +} + +/* Set to true if getdents64 should produce only one entry. */ +static bool one_entry_per_getdents64; + +static void +fuse_thread (struct support_fuse *f, void *closure) +{ + struct fuse_in_header *inh; + while ((inh = support_fuse_next (f)) != NULL) + { + if (support_fuse_handle_mountpoint (f) + || (inh->nodeid == 1 && support_fuse_handle_directory (f))) + continue; + switch (inh->opcode) + { + case FUSE_READDIR: + if (inh->nodeid == 1) + { + uint64_t offset = support_fuse_cast (READ, inh)->offset; + struct support_fuse_dirstream *d + = support_fuse_prepare_readdir (f); + while (true) + { + offset = add_directory_entry (d, offset); + if (offset == 0 || one_entry_per_getdents64) + break; + } + support_fuse_reply_prepared (f); + } + else + support_fuse_reply_error (f, EIO); + break; + default: + FAIL ("unexpected event %s", support_fuse_opcode (inh->opcode)); + support_fuse_reply_error (f, EIO); + } + } +} + +static int +do_test (void) +{ + support_fuse_init (); + + for (enum support_readdir_op op = 0; op <= support_readdir_op_last (); ++op) + { + struct support_fuse *f = support_fuse_mount (fuse_thread, NULL); + DIR *dir = xopendir (support_fuse_mountpoint (f)); + struct support_dirent e = { 0, }; + + TEST_VERIFY (support_readdir (dir, op, &e)); + TEST_COMPARE_STRING (e.d_name, "."); + TEST_COMPARE (e.d_ino, 1); + + TEST_VERIFY (support_readdir (dir, op, &e)); + TEST_COMPARE_STRING (e.d_name, ".."); + TEST_COMPARE (e.d_ino, 1); + + TEST_VERIFY (support_readdir (dir, op, &e)); + TEST_COMPARE_STRING (e.d_name, "before"); + TEST_COMPARE (e.d_ino, 2); + + TEST_VERIFY (support_readdir (dir, op, &e)); + TEST_COMPARE_STRING (e.d_name, "zero"); + TEST_COMPARE (e.d_ino, 0); + + TEST_VERIFY (support_readdir (dir, op, &e)); + TEST_COMPARE_STRING (e.d_name, "after"); + TEST_COMPARE (e.d_ino, 3); + + TEST_VERIFY (!support_readdir (dir, op, &e)); + + free (e.d_name); + xclosedir (dir); + support_fuse_unmount (f); + } + + return 0; +} + +#include diff --git a/sysdeps/unix/sysv/linux/readdir64_r.c b/sysdeps/unix/sysv/linux/readdir64_r.c index 7ad7e5945b..c42a161ffc 100644 --- a/sysdeps/unix/sysv/linux/readdir64_r.c +++ b/sysdeps/unix/sysv/linux/readdir64_r.c @@ -37,7 +37,7 @@ __readdir64_r (DIR *dirp, struct dirent64 *entry, struct dirent64 **result) __libc_lock_lock (dirp->lock); - do + while (1) { if (dirp->offset >= dirp->size) { @@ -79,26 +79,21 @@ __readdir64_r (DIR *dirp, struct dirent64 *entry, struct dirent64 **result) dirp->filepos = dp->d_off; - if (reclen > offsetof (struct dirent64, d_name) + NAME_MAX + 1) + if (reclen <= offsetof (struct dirent64, d_name) + NAME_MAX + 1) + break; + + /* The record is very long. It could still fit into the + caller-supplied buffer if we can skip padding at the end. */ + size_t namelen = _D_EXACT_NAMLEN (dp); + if (namelen <= NAME_MAX) { - /* The record is very long. It could still fit into the - caller-supplied buffer if we can skip padding at the - end. */ - size_t namelen = _D_EXACT_NAMLEN (dp); - if (namelen <= NAME_MAX) - reclen = offsetof (struct dirent64, d_name) + namelen + 1; - else - { - /* The name is too long. Ignore this file. */ - dirp->errcode = ENAMETOOLONG; - dp->d_ino = 0; - continue; - } + reclen = offsetof (struct dirent64, d_name) + namelen + 1; + break; } - /* Skip deleted and ignored files. */ + /* The name is too long. Ignore this file. */ + dirp->errcode = ENAMETOOLONG; } - while (dp->d_ino == 0); if (dp != NULL) {