fuse: verify nlink
commit c634da718db9b2fac201df2ae1b1b095344ce5eb upstream.
When adding a new hard link, make sure that i_nlink doesn't overflow.
Fixes: ac45d61357e8 ("fuse: fix nlink after unlink")
Cc: <stable@vger.kernel.org> # v3.4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 1d9fec9..15b7559 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -830,7 +830,8 @@
spin_lock(&fc->lock);
fi->attr_version = ++fc->attr_version;
- inc_nlink(inode);
+ if (likely(inode->i_nlink < UINT_MAX))
+ inc_nlink(inode);
spin_unlock(&fc->lock);
fuse_invalidate_attr(inode);
fuse_update_ctime(inode);