diff options
Diffstat (limited to 'fs/super.c')
| -rw-r--r-- | fs/super.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/fs/super.c b/fs/super.c index f1d873331..5b8974e5b 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1167,7 +1167,8 @@ static int copy_mount_options (const void *data, unsigned long *where) { int i; unsigned long page; - + unsigned long size; + *where = 0; if (!data) return 0; @@ -1179,13 +1180,18 @@ static int copy_mount_options (const void *data, unsigned long *where) * gave us is valid. Just in case, we'll zero * the remainder of the page. */ - i = copy_from_user((void *)page, data, PAGE_SIZE); - if (i == PAGE_SIZE) { + /* copy_from_user cannot cross TASK_SIZE ! */ + size = TASK_SIZE - (unsigned long)data; + if (size > PAGE_SIZE) + size = PAGE_SIZE; + + i = size - copy_from_user((void *)page, data, size); + if (!i) { free_page(page); return -EFAULT; } - if (i) - memset((char *)page + PAGE_SIZE - i, 0, i); + if (i != PAGE_SIZE) + memset((char *)page + i, 0, PAGE_SIZE - i); *where = page; return 0; } |