qga: Rewrite code where using readdir_r

If readdir_r fails, error_setg_errno will reference the freed
pointer *dirpath*.

Moreover, readdir_r may cause a buffer overflow, using readdir instead.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This commit is contained in:
zhanghailiang 2014-09-19 11:09:10 +08:00 committed by Michael Roth
parent 01a2050fa5
commit e668d1b854

View file

@ -956,7 +956,7 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath,
{
DIR *dir;
char *dirpath;
struct dirent entry, *result;
struct dirent *entry;
dirpath = g_strdup_printf("%s/slaves", syspath);
dir = opendir(dirpath);
@ -965,22 +965,24 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath,
g_free(dirpath);
return;
}
g_free(dirpath);
for (;;) {
if (readdir_r(dir, &entry, &result) != 0) {
error_setg_errno(errp, errno, "readdir_r(\"%s\")", dirpath);
break;
}
if (!result) {
errno = 0;
entry = readdir(dir);
if (entry == NULL) {
if (errno) {
error_setg_errno(errp, errno, "readdir(\"%s\")", dirpath);
}
break;
}
if (entry.d_type == DT_LNK) {
g_debug(" slave device '%s'", entry.d_name);
dirpath = g_strdup_printf("%s/slaves/%s", syspath, entry.d_name);
build_guest_fsinfo_for_device(dirpath, fs, errp);
g_free(dirpath);
if (entry->d_type == DT_LNK) {
char *path;
g_debug(" slave device '%s'", entry->d_name);
path = g_strdup_printf("%s/slaves/%s", syspath, entry->d_name);
build_guest_fsinfo_for_device(path, fs, errp);
g_free(path);
if (*errp) {
break;
@ -988,6 +990,7 @@ static void build_guest_fsinfo_for_virtual_device(char const *syspath,
}
}
g_free(dirpath);
closedir(dir);
}