[PATCH 5.3 045/105] fuse: verify nlink

Greg Kroah-Hartman
2019-12-11T15:13:29Z

From: Miklos Szeredi <mszeredi@redhat.com>

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>

---
fs/fuse/dir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -814,7 +814,8 @@ static int fuse_link(struct dentry *entr

spin_lock(&fi->lock);
fi->attr_version = atomic64_inc_return(&fc->attr_version);
- inc_nlink(inode);
+ if (likely(inode->i_nlink < UINT_MAX))
+ inc_nlink(inode);
spin_unlock(&fi->lock);
fuse_invalidate_attr(inode);
fuse_update_ctime(inode);