dlm: dlm/user.c input validation fixes
a) in device_write(): add sentinel NUL byte, making sure that lspace.name will
be NUL-terminated
b) in compat_input() be keep it simple about the amounts of data we are copying.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Teigland <teigland@redhat.com>
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 7cbc682..c306045 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -82,7 +82,7 @@
static void compat_input(struct dlm_write_request *kb,
struct dlm_write_request32 *kb32,
- int max_namelen)
+ size_t count)
{
kb->version[0] = kb32->version[0];
kb->version[1] = kb32->version[1];
@@ -94,7 +94,8 @@
kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
kb->i.lspace.flags = kb32->i.lspace.flags;
kb->i.lspace.minor = kb32->i.lspace.minor;
- strcpy(kb->i.lspace.name, kb32->i.lspace.name);
+ memcpy(kb->i.lspace.name, kb32->i.lspace.name, count -
+ offsetof(struct dlm_write_request32, i.lspace.name));
} else if (kb->cmd == DLM_USER_PURGE) {
kb->i.purge.nodeid = kb32->i.purge.nodeid;
kb->i.purge.pid = kb32->i.purge.pid;
@@ -112,11 +113,8 @@
kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
- if (kb->i.lock.namelen <= max_namelen)
- memcpy(kb->i.lock.name, kb32->i.lock.name,
- kb->i.lock.namelen);
- else
- kb->i.lock.namelen = max_namelen;
+ memcpy(kb->i.lock.name, kb32->i.lock.name, count -
+ offsetof(struct dlm_write_request32, i.lock.name));
}
}
@@ -508,7 +506,7 @@
#endif
return -EINVAL;
- kbuf = kmalloc(count, GFP_KERNEL);
+ kbuf = kzalloc(count + 1, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
@@ -526,15 +524,14 @@
if (!kbuf->is64bit) {
struct dlm_write_request32 *k32buf;
k32buf = (struct dlm_write_request32 *)kbuf;
- kbuf = kmalloc(count + (sizeof(struct dlm_write_request) -
+ kbuf = kmalloc(count + 1 + (sizeof(struct dlm_write_request) -
sizeof(struct dlm_write_request32)), GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
if (proc)
set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
- compat_input(kbuf, k32buf,
- count - sizeof(struct dlm_write_request32));
+ compat_input(kbuf, k32buf, count + 1);
kfree(k32buf);
}
#endif