Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [syzbot] INFO: task hung in io_uring_del_tctx_node
To:     syzbot <syzbot+111d2a03f51f5ae73775@syzkaller.appspotmail.com>,
        asml.silence@gmail.com, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
References: <00000000000064b6b405ccb41113@google.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <5b3f8081-fbdd-ea2c-eddb-292d02be98a8@kernel.dk>
Date:   Thu, 23 Sep 2021 20:43:45 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <00000000000064b6b405ccb41113@google.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 9/23/21 7:57 PM, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    92477dd1faa6 Merge tag 's390-5.15-ebpf-jit-fixes' of git:/..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1471785b300000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e917f3dfc452c977
> dashboard link: https://syzkaller.appspot.com/bug?extid=111d2a03f51f5ae73775
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1511c4f7300000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=132d1d1d300000


diff --git a/fs/io_uring.c b/fs/io_uring.c
index fe5e613b960f..efb244deb081 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9636,8 +9641,10 @@ static void io_uring_clean_tctx(struct io_uring_task *tctx)
 	struct io_tctx_node *node;
 	unsigned long index;
 
-	xa_for_each(&tctx->xa, index, node)
+	xa_for_each(&tctx->xa, index, node) {
 		io_uring_del_tctx_node(index);
+		cond_resched();
+	}
 	if (wq) {
 		/*
 		 * Must be after io_uring_del_task_file() (removes nodes under

-- 
Jens Axboe