diff options
| -rw-r--r-- | fs/libfs.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index dcec3d3ea64..662a28e4f66 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -527,14 +527,18 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, const void *from, size_t available) { loff_t pos = *ppos; + size_t ret; + if (pos < 0) return -EINVAL; - if (pos >= available) + if (pos >= available || !count) return 0; if (count > available - pos) count = available - pos; - if (copy_to_user(to, from + pos, count)) + ret = copy_to_user(to, from + pos, count); + if (ret == count) return -EFAULT; + count -= ret; *ppos = pos + count; return count; } |