io_uring/fs: consider link->flags when getting path for LINKAT

commit 8479063f1fbee201a8739130e816cc331b675838 upstream.

In order for `AT_EMPTY_PATH` to work as expected, the fact
that the user wants that behavior needs to make it to `getname_flags`
or it will return ENOENT.

Fixes: cf30da90bc3a ("io_uring: add support for IORING_OP_LINKAT")
Cc:  <stable@vger.kernel.org>
Link: https://github.com/axboe/liburing/issues/995
Signed-off-by: Charles Mirabile <cmirabil@redhat.com>
Link: https://lore.kernel.org/r/20231120105545.1209530-1-cmirabil@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/io_uring/fs.c b/io_uring/fs.c
index 08e3b17..eccea85 100644 (file)
--- a/io_uring/fs.c
+++ b/io_uring/fs.c
@@ -254,7 +254,7 @@ int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
        lnk->flags = READ_ONCE(sqe->hardlink_flags);
 
-       lnk->oldpath = getname(oldf);
+       lnk->oldpath = getname_uflags(oldf, lnk->flags);
        if (IS_ERR(lnk->oldpath))
                return PTR_ERR(lnk->oldpath);