Re: [syzbot] INFO: task hung in io_uring_del_tctx_node

From: Jens Axboe
Date: Thu Sep 23 2021 - 22:43:57 EST


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