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From: Jeff Moyer <jmoyer@redhat.com>
To: axboe@kernel.dk
Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
	linux-block@vger.kernel.org
Subject: [patch] io_uring: don't allow duplicate registrations
Date: Wed, 16 Jan 2019 19:50:12 -0500	[thread overview]
Message-ID: <x497ef4hzuj.fsf@segfault.boston.devel.redhat.com> (raw)

Hi, Jens,

It looks to me like calling io_uring_register more than once (for either
IORING_REGISTER_BUFFERS or IORING_REGISTER_FILES) will leak the
references taken in previous calls.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>

---

If this makes sense to you, feel free to just fold this into your
patches w/o any attribution.

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3650e8b63a32..f0492b0e23a0 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1399,6 +1399,9 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 	if (!nr_args)
 		return -EINVAL;
 
+	if (ctx->user_files)
+		return -EINVAL;
+
 	ctx->user_files = kcalloc(nr_args, sizeof(struct file *), GFP_KERNEL);
 	if (!ctx->user_files)
 		return -ENOMEM;
@@ -1580,6 +1583,9 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
 	if (!nr_args || nr_args > UIO_MAXIOV)
 		return -EINVAL;
 
+	if (ctx->user_bufs)
+		return -EINVAL;
+
 	ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
 					GFP_KERNEL);
 	if (!ctx->user_bufs)

             reply	other threads:[~2019-01-17  0:50 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-17  0:50 Jeff Moyer [this message]
2019-01-17  1:23 ` [patch] io_uring: don't allow duplicate registrations Jens Axboe
2019-01-17  1:31   ` Jeff Moyer
2019-01-17  1:33     ` Jens Axboe

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