Files
libguestfs/daemon/readdir.c
Pino Toscano 7618e41d33 daemon: readdir: fix invalid memory access on error
If "strdup (d->d_name)" fails with "i" > 0, then both "p" and
"ret->guestfs_int_dirent_list_val" are non-null pointers, but the latter
is no more valid (since "p" is the new realloc'ed buffer). Hence, trying
to free both will access to invalid memory.

Make sure to free only one of them, "p" if not null or
"ret->guestfs_int_dirent_list_val" otherwise.
2015-01-20 16:09:53 +01:00

123 lines
2.8 KiB
C

/* libguestfs - the guestfsd daemon
* Copyright (C) 2009 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>
#include "daemon.h"
#include "actions.h"
static void
free_int_dirent_list (guestfs_int_dirent *p, size_t len)
{
size_t i;
for (i = 0; i < len; ++i) {
free (p[i].name);
}
free (p);
}
guestfs_int_dirent_list *
do_readdir (const char *path)
{
guestfs_int_dirent_list *ret;
guestfs_int_dirent v;
DIR *dir;
struct dirent *d;
size_t i;
ret = malloc (sizeof *ret);
if (ret == NULL) {
reply_with_perror ("malloc");
return NULL;
}
ret->guestfs_int_dirent_list_len = 0;
ret->guestfs_int_dirent_list_val = NULL;
CHROOT_IN;
dir = opendir (path);
CHROOT_OUT;
if (dir == NULL) {
reply_with_perror ("opendir: %s", path);
free (ret);
return NULL;
}
i = 0;
while ((d = readdir (dir)) != NULL) {
guestfs_int_dirent *p;
p = realloc (ret->guestfs_int_dirent_list_val,
sizeof (guestfs_int_dirent) * (i+1));
v.name = strdup (d->d_name);
if (!p || !v.name) {
reply_with_perror ("allocate");
if (p) {
free_int_dirent_list (p, i);
} else {
free_int_dirent_list (ret->guestfs_int_dirent_list_val, i);
}
free (v.name);
free (ret);
closedir (dir);
return NULL;
}
ret->guestfs_int_dirent_list_val = p;
v.ino = d->d_ino;
#ifdef HAVE_STRUCT_DIRENT_D_TYPE
switch (d->d_type) {
case DT_BLK: v.ftyp = 'b'; break;
case DT_CHR: v.ftyp = 'c'; break;
case DT_DIR: v.ftyp = 'd'; break;
case DT_FIFO: v.ftyp = 'f'; break;
case DT_LNK: v.ftyp = 'l'; break;
case DT_REG: v.ftyp = 'r'; break;
case DT_SOCK: v.ftyp = 's'; break;
case DT_UNKNOWN: v.ftyp = 'u'; break;
default: v.ftyp = '?'; break;
}
#else
v.ftyp = 'u';
#endif
ret->guestfs_int_dirent_list_val[i] = v;
i++;
}
ret->guestfs_int_dirent_list_len = i;
if (closedir (dir) == -1) {
reply_with_perror ("closedir");
free (ret->guestfs_int_dirent_list_val);
free (ret);
return NULL;
}
return ret;
}