[PATCH 5.15 773/779] io_uring: mem-account pbuf buckets

[Greg Kroah-Hartman]

From: Pavel Begunkov <asml.silence@xxxxxxxxx>

commit cc18cc5e82033d406f54144ad6f8092206004684 upstream.

Potentially, someone may create as many pbuf bucket as there are indexes
in an xarray without any other restrictions bounding our memory usage,
put memory needed for the buckets under memory accounting.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/d34c452e45793e978d26e2606211ec9070d329ea.1659622312.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/io_uring.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4477,7 +4477,8 @@ static int io_provide_buffers(struct io_
 
 	ret = io_add_buffers(p, &head);
 	if (ret >= 0 && !list) {
-		ret = xa_insert(&ctx->io_buffers, p->bgid, head, GFP_KERNEL);
+		ret = xa_insert(&ctx->io_buffers, p->bgid, head,
+				GFP_KERNEL_ACCOUNT);
 		if (ret < 0)
 			__io_remove_buffers(ctx, head, p->bgid, -1U);
 	}