Message ID | 20210927152613.1551692-1-adhemerval.zanella@linaro.org |
---|---|
State | New |
Headers | show |
Series | [v6] io: Fix ftw internal realloc buffer (BZ #28126) | expand |
Ping. On 27/09/2021 12:26, Adhemerval Zanella wrote: > The 106ff08526d3ca did not take in consideration the buffer might be > reallocated if the total path is larger than PATH_MAX. The realloc > uses 'dirbuf', where 'dirstreams' is the allocated buffer. > > Checked on x86_64-linux-gnu. > --- > io/Makefile | 1 + > io/ftw.c | 13 +++--- > io/tst-ftw-bz28126.c | 97 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 106 insertions(+), 5 deletions(-) > create mode 100644 io/tst-ftw-bz28126.c > > diff --git a/io/Makefile b/io/Makefile > index 9871ecbc74..ecf65aba60 100644 > --- a/io/Makefile > +++ b/io/Makefile > @@ -79,6 +79,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \ > tst-futimens \ > tst-utimensat \ > tst-closefrom \ > + tst-ftw-bz28126 > > tests-time64 := \ > tst-futimens-time64 \ > diff --git a/io/ftw.c b/io/ftw.c > index f0db173727..3964c07bbb 100644 > --- a/io/ftw.c > +++ b/io/ftw.c > @@ -391,13 +391,16 @@ process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, > if (data->dirbufsize < new_buflen) > { > /* Enlarge the buffer. */ > - char *newp; > - > - data->dirbufsize = 2 * new_buflen; > - newp = (char *) realloc (data->dirbuf, data->dirbufsize); > + size_t newsize = 2 * new_buflen; > + void *newp = realloc (data->dirstreams, data->maxdir > + * sizeof (struct dir_data *) > + + newsize); > if (newp == NULL) > return -1; > - data->dirbuf = newp; > + data->dirstreams = newp; > + data->dirbufsize = newsize; > + data->dirbuf = (char *) data->dirstreams > + + data->maxdir * sizeof (struct dir_data *); > } > > *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; > diff --git a/io/tst-ftw-bz28126.c b/io/tst-ftw-bz28126.c > new file mode 100644 > index 0000000000..94044ab9d1 > --- /dev/null > +++ b/io/tst-ftw-bz28126.c > @@ -0,0 +1,97 @@ > +/* Check if internal buffer reallocation work for large paths (BZ #28126) > + Copyright (C) 2021 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 > + <https://www.gnu.org/licenses/>. */ > + > +#include <errno.h> > +#include <ftw.h> > +#include <limits.h> > +#include <string.h> > +#include <stdlib.h> > +#include <support/check.h> > +#include <support/support.h> > +#include <support/temp_file.h> > +#include <support/xunistd.h> > +#include <stdio.h> > + > +static int > +my_func (const char *file, const struct stat *sb, int flag) > +{ > + return 0; > +} > + > +static const char folder[NAME_MAX] = { [0 ... 253] = 'a', [254] = '\0' }; > + > +#define NSUBFOLDERS 16 > +static int nsubfolders; > + > +static void > +do_cleanup (void) > +{ > + xchdir (".."); > + for (int i = 0; i < nsubfolders; i++) > + { > + remove (folder); > + xchdir (".."); > + } > + remove (folder); > +} > +#define CLEANUP_HANDLER do_cleanup > + > +static void > +check_mkdir (const char *path) > +{ > + int r = mkdir (path, 0777); > + /* Some filesystem such as overlayfs does not support larger path required > + to trigger the internal buffer reallocation. */ > + if (r != 0) > + { > + if (errno == ENAMETOOLONG) > + FAIL_UNSUPPORTED ("the filesystem does not support the required" > + "large path"); > + else > + FAIL_EXIT1 ("mkdir (\"%s\", 0%o): %m", folder, 0777); > + } > +} > + > +static int > +do_test (void) > +{ > + char *tempdir = support_create_temp_directory ("tst-bz28126"); > + > + /* Create path with various subfolders to force an internal buffer > + reallocation within ntfw. */ > + char *path = xasprintf ("%s/%s", tempdir, folder); > + check_mkdir (path); > + xchdir (path); > + free (path); > + for (int i = 0; i < NSUBFOLDERS - 1; i++) > + { > + check_mkdir (folder); > + xchdir (folder); > + nsubfolders++; > + } > + > + TEST_COMPARE (ftw (tempdir, my_func, 20), 0); > + > + free (tempdir); > + > + do_cleanup (); > + > + return 0; > +} > + > +#include <support/test-driver.c> >
On Mon, Sep 27, 2021 at 8:26 AM Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote: > > The 106ff08526d3ca did not take in consideration the buffer might be > reallocated if the total path is larger than PATH_MAX. The realloc > uses 'dirbuf', where 'dirstreams' is the allocated buffer. > > Checked on x86_64-linux-gnu. > --- > io/Makefile | 1 + > io/ftw.c | 13 +++--- > io/tst-ftw-bz28126.c | 97 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 106 insertions(+), 5 deletions(-) > create mode 100644 io/tst-ftw-bz28126.c > > diff --git a/io/Makefile b/io/Makefile > index 9871ecbc74..ecf65aba60 100644 > --- a/io/Makefile > +++ b/io/Makefile > @@ -79,6 +79,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \ > tst-futimens \ > tst-utimensat \ > tst-closefrom \ > + tst-ftw-bz28126 > > tests-time64 := \ > tst-futimens-time64 \ > diff --git a/io/ftw.c b/io/ftw.c > index f0db173727..3964c07bbb 100644 > --- a/io/ftw.c > +++ b/io/ftw.c > @@ -391,13 +391,16 @@ process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, > if (data->dirbufsize < new_buflen) > { > /* Enlarge the buffer. */ > - char *newp; > - > - data->dirbufsize = 2 * new_buflen; > - newp = (char *) realloc (data->dirbuf, data->dirbufsize); > + size_t newsize = 2 * new_buflen; > + void *newp = realloc (data->dirstreams, data->maxdir > + * sizeof (struct dir_data *) > + + newsize); > if (newp == NULL) > return -1; > - data->dirbuf = newp; > + data->dirstreams = newp; > + data->dirbufsize = newsize; > + data->dirbuf = (char *) data->dirstreams > + + data->maxdir * sizeof (struct dir_data *); This almost duplicates: data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX); data.dirstreams = malloc (data.maxdir * sizeof (struct dir_data *) + data.dirbufsize); if (data.dirstreams == NULL) return -1; memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *)); data.dirbuf = (char *) data.dirstreams + data.maxdir * sizeof (struct dir_data *); Can you write a helper function and call it in these 2 places?
On 9/27/21 20:56, Adhemerval Zanella wrote: > The 106ff08526d3ca did not take in consideration the buffer might be > reallocated if the total path is larger than PATH_MAX. The realloc > uses 'dirbuf', where 'dirstreams' is the allocated buffer. > > Checked on x86_64-linux-gnu. LGTM. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > --- > io/Makefile | 1 + > io/ftw.c | 13 +++--- > io/tst-ftw-bz28126.c | 97 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 106 insertions(+), 5 deletions(-) > create mode 100644 io/tst-ftw-bz28126.c > > diff --git a/io/Makefile b/io/Makefile > index 9871ecbc74..ecf65aba60 100644 > --- a/io/Makefile > +++ b/io/Makefile > @@ -79,6 +79,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \ > tst-futimens \ > tst-utimensat \ > tst-closefrom \ > + tst-ftw-bz28126 > > tests-time64 := \ > tst-futimens-time64 \ > diff --git a/io/ftw.c b/io/ftw.c > index f0db173727..3964c07bbb 100644 > --- a/io/ftw.c > +++ b/io/ftw.c > @@ -391,13 +391,16 @@ process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, > if (data->dirbufsize < new_buflen) > { > /* Enlarge the buffer. */ > - char *newp; > - > - data->dirbufsize = 2 * new_buflen; > - newp = (char *) realloc (data->dirbuf, data->dirbufsize); > + size_t newsize = 2 * new_buflen; > + void *newp = realloc (data->dirstreams, data->maxdir > + * sizeof (struct dir_data *) > + + newsize); > if (newp == NULL) > return -1; > - data->dirbuf = newp; > + data->dirstreams = newp; > + data->dirbufsize = newsize; > + data->dirbuf = (char *) data->dirstreams > + + data->maxdir * sizeof (struct dir_data *); > } > > *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; > diff --git a/io/tst-ftw-bz28126.c b/io/tst-ftw-bz28126.c > new file mode 100644 > index 0000000000..94044ab9d1 > --- /dev/null > +++ b/io/tst-ftw-bz28126.c > @@ -0,0 +1,97 @@ > +/* Check if internal buffer reallocation work for large paths (BZ #28126) > + Copyright (C) 2021 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 > + <https://www.gnu.org/licenses/>. */ > + > +#include <errno.h> > +#include <ftw.h> > +#include <limits.h> > +#include <string.h> > +#include <stdlib.h> > +#include <support/check.h> > +#include <support/support.h> > +#include <support/temp_file.h> > +#include <support/xunistd.h> > +#include <stdio.h> > + > +static int > +my_func (const char *file, const struct stat *sb, int flag) > +{ > + return 0; > +} > + > +static const char folder[NAME_MAX] = { [0 ... 253] = 'a', [254] = '\0' }; > + > +#define NSUBFOLDERS 16 > +static int nsubfolders; > + > +static void > +do_cleanup (void) > +{ > + xchdir (".."); > + for (int i = 0; i < nsubfolders; i++) > + { > + remove (folder); > + xchdir (".."); > + } > + remove (folder); > +} > +#define CLEANUP_HANDLER do_cleanup > + > +static void > +check_mkdir (const char *path) > +{ > + int r = mkdir (path, 0777); > + /* Some filesystem such as overlayfs does not support larger path required > + to trigger the internal buffer reallocation. */ > + if (r != 0) > + { > + if (errno == ENAMETOOLONG) > + FAIL_UNSUPPORTED ("the filesystem does not support the required" > + "large path"); > + else > + FAIL_EXIT1 ("mkdir (\"%s\", 0%o): %m", folder, 0777); > + } > +} > + > +static int > +do_test (void) > +{ > + char *tempdir = support_create_temp_directory ("tst-bz28126"); > + > + /* Create path with various subfolders to force an internal buffer > + reallocation within ntfw. */ > + char *path = xasprintf ("%s/%s", tempdir, folder); > + check_mkdir (path); > + xchdir (path); > + free (path); > + for (int i = 0; i < NSUBFOLDERS - 1; i++) > + { > + check_mkdir (folder); > + xchdir (folder); > + nsubfolders++; > + } > + > + TEST_COMPARE (ftw (tempdir, my_func, 20), 0); > + > + free (tempdir); > + > + do_cleanup (); > + > + return 0; > +} > + > +#include <support/test-driver.c> >
diff --git a/io/Makefile b/io/Makefile index 9871ecbc74..ecf65aba60 100644 --- a/io/Makefile +++ b/io/Makefile @@ -79,6 +79,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \ tst-futimens \ tst-utimensat \ tst-closefrom \ + tst-ftw-bz28126 tests-time64 := \ tst-futimens-time64 \ diff --git a/io/ftw.c b/io/ftw.c index f0db173727..3964c07bbb 100644 --- a/io/ftw.c +++ b/io/ftw.c @@ -391,13 +391,16 @@ process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, if (data->dirbufsize < new_buflen) { /* Enlarge the buffer. */ - char *newp; - - data->dirbufsize = 2 * new_buflen; - newp = (char *) realloc (data->dirbuf, data->dirbufsize); + size_t newsize = 2 * new_buflen; + void *newp = realloc (data->dirstreams, data->maxdir + * sizeof (struct dir_data *) + + newsize); if (newp == NULL) return -1; - data->dirbuf = newp; + data->dirstreams = newp; + data->dirbufsize = newsize; + data->dirbuf = (char *) data->dirstreams + + data->maxdir * sizeof (struct dir_data *); } *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; diff --git a/io/tst-ftw-bz28126.c b/io/tst-ftw-bz28126.c new file mode 100644 index 0000000000..94044ab9d1 --- /dev/null +++ b/io/tst-ftw-bz28126.c @@ -0,0 +1,97 @@ +/* Check if internal buffer reallocation work for large paths (BZ #28126) + Copyright (C) 2021 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 + <https://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <ftw.h> +#include <limits.h> +#include <string.h> +#include <stdlib.h> +#include <support/check.h> +#include <support/support.h> +#include <support/temp_file.h> +#include <support/xunistd.h> +#include <stdio.h> + +static int +my_func (const char *file, const struct stat *sb, int flag) +{ + return 0; +} + +static const char folder[NAME_MAX] = { [0 ... 253] = 'a', [254] = '\0' }; + +#define NSUBFOLDERS 16 +static int nsubfolders; + +static void +do_cleanup (void) +{ + xchdir (".."); + for (int i = 0; i < nsubfolders; i++) + { + remove (folder); + xchdir (".."); + } + remove (folder); +} +#define CLEANUP_HANDLER do_cleanup + +static void +check_mkdir (const char *path) +{ + int r = mkdir (path, 0777); + /* Some filesystem such as overlayfs does not support larger path required + to trigger the internal buffer reallocation. */ + if (r != 0) + { + if (errno == ENAMETOOLONG) + FAIL_UNSUPPORTED ("the filesystem does not support the required" + "large path"); + else + FAIL_EXIT1 ("mkdir (\"%s\", 0%o): %m", folder, 0777); + } +} + +static int +do_test (void) +{ + char *tempdir = support_create_temp_directory ("tst-bz28126"); + + /* Create path with various subfolders to force an internal buffer + reallocation within ntfw. */ + char *path = xasprintf ("%s/%s", tempdir, folder); + check_mkdir (path); + xchdir (path); + free (path); + for (int i = 0; i < NSUBFOLDERS - 1; i++) + { + check_mkdir (folder); + xchdir (folder); + nsubfolders++; + } + + TEST_COMPARE (ftw (tempdir, my_func, 20), 0); + + free (tempdir); + + do_cleanup (); + + return 0; +} + +#include <support/test-driver.c>