[PATCH 5.10 008/103] io_uring: Fix return value from alloc_fixed_file_ref_node

Greg Kroah-Hartman
2021-01-15T12:48:39Z

From: Matthew Wilcox (Oracle) <willy@infradead.org>

[ Upstream commit 3e2224c5867fead6c0b94b84727cc676ac6353a3 ]

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: 1ffc54220c44 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/io_uring.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 492492a010a2f..4833b68f1a1cc 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7461,12 +7461,12 @@ 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);
@@ -7560,9 +7560,9 @@ 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);
@@ -7662,8 +7662,8 @@ 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);
--
2.27.0