From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Wed, 6 Jan 2021 16:09:26 +0000 (+0000)
Subject: io_uring: Fix return value from alloc_fixed_file_ref_node
X-Git-Tag: baikal/mips/sdk5.9~11808^2~7
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=885f4c8dce261ad39170fff1c3497719133c8173;p=kernel.git

io_uring: Fix return value from alloc_fixed_file_ref_node

alloc_fixed_file_ref_node() currently returns an ERR_PTR on failure.
io_sqe_files_unregister() expects it to return NULL and since it can only
return -ENOMEM, it makes more sense to change alloc_fixed_file_ref_node()
to behave that way.

Fixes: ff26b8748ea4 ("io_uring: fix io_sqe_files_unregister() hangs")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index dc92ca5090a39..27a8c226abf8c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7696,12 +7696,12 @@ static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
 
 	ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
 	if (!ref_node)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
 			    0, GFP_KERNEL)) {
 		kfree(ref_node);
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 	}
 	INIT_LIST_HEAD(&ref_node->node);
 	INIT_LIST_HEAD(&ref_node->file_list);
@@ -7795,9 +7795,9 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 	}
 
 	ref_node = alloc_fixed_file_ref_node(ctx);
-	if (IS_ERR(ref_node)) {
+	if (!ref_node) {
 		io_sqe_files_unregister(ctx);
-		return PTR_ERR(ref_node);
+		return -ENOMEM;
 	}
 
 	io_sqe_files_set_node(file_data, ref_node);
@@ -7897,8 +7897,8 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 		return -EINVAL;
 
 	ref_node = alloc_fixed_file_ref_node(ctx);
-	if (IS_ERR(ref_node))
-		return PTR_ERR(ref_node);
+	if (!ref_node)
+		return -ENOMEM;
 
 	done = 0;
 	fds = u64_to_user_ptr(up->fds);