From a6ead78130ad6b3eadaaa5811be1ddaf1f6ec405 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 22 Jul 2021 17:08:07 -0600 Subject: [PATCH] io_uring: fix early fdput() of file commit 0cc936f74bcacb039b7533aeac0a887dfc896bf6 upstream. A previous commit shuffled some code around, and inadvertently used struct file after fdput() had been called on it. As we can't touch the file post fdput() dropping our reference, move the fdput() to after that has been done. Cc: Pavel Begunkov Cc: stable@vger.kernel.org Link: https://lore.kernel.org/io-uring/YPnqM0fY3nM5RdRI@zeniv-ca.linux.org.uk/ Fixes: f2a48dd09b8e ("io_uring: refactor io_sq_offload_create()") Reported-by: Al Viro Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 437c9f602b7d8..df4288776815e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7953,9 +7953,11 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, f = fdget(p->wq_fd); if (!f.file) return -ENXIO; - fdput(f); - if (f.file->f_op != &io_uring_fops) + if (f.file->f_op != &io_uring_fops) { + fdput(f); return -EINVAL; + } + fdput(f); } if (ctx->flags & IORING_SETUP_SQPOLL) { struct task_struct *tsk;