From: Pavel Begunkov asml.silence@gmail.com
[ Upstream commit a07211e3001435fe8591b992464cd8d5e3c98c5a ]
It's safer to not touch scm_fp_list after we queued an skb to which it was assigned, there might be races lurking if we screw subtle sync guarantees on the io_uring side.
Fixes: 6b06314c47e14 ("io_uring: add file set registration") Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- fs/io_uring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 5959b0359524..3580fa2dabc8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7346,8 +7346,12 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) refcount_add(skb->truesize, &sk->sk_wmem_alloc); skb_queue_head(&sk->sk_receive_queue, skb);
- for (i = 0; i < nr_files; i++) - fput(fpl->fp[i]); + for (i = 0; i < nr; i++) { + struct file *file = io_file_from_index(ctx, i + offset); + + if (file) + fput(file); + } } else { kfree_skb(skb); free_uid(fpl->user);