From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sat, 29 May 2021 11:01:02 +0000 (+0100)
Subject: io_uring: fix misaccounting fix buf pinned pages
X-Git-Tag: accepted/tizen/unified/20230118.172025~7081^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=216e5835966a709bb87a4d94a7343dd90ab0bd64;p=platform%2Fkernel%2Flinux-rpi.git

io_uring: fix misaccounting fix buf pinned pages

As Andres reports "... io_sqe_buffer_register() doesn't initialize imu.
io_buffer_account_pin() does imu->acct_pages++, before calling
io_account_mem(ctx, imu->acct_pages).", leading to evevntual -ENOMEM.

Initialise the field.

Reported-by: Andres Freund <andres@anarazel.de>
Fixes: 41edf1a5ec967 ("io_uring: keep table of pointers to ubufs")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/438a6f46739ae5e05d9c75a0c8fa235320ff367c.1622285901.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 903458a..42380ed 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8228,6 +8228,7 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
 {
 	int i, ret;
 
+	imu->acct_pages = 0;
 	for (i = 0; i < nr_pages; i++) {
 		if (!PageCompound(pages[i])) {
 			imu->acct_pages++;