[PATCH 3.16 088/148] fuse: verify nlink

Ben Hutchings
2020-02-08T18:33:38Z

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")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/fuse/dir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -890,7 +890,8 @@ static int fuse_link(struct dentry *entr

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);