[PATCH 5.15 166/171] aio: Fix incorrect usage of eventfd_signal_allowed()

Greg Kroah-Hartman
2021-12-13T10:30:21Z

From: Xie Yongji <xieyongji@bytedance.com>

commit 4b3749865374899e115aa8c48681709b086fe6d3 upstream.

We should defer eventfd_signal() to the workqueue when
eventfd_signal_allowed() return false rather than return
true.

Fixes: b542e383d8c0 ("eventfd: Make signal recursion protection a task bit")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210913111928.98-1-xieyongji@bytedance.com
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/aio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1761,7 +1761,7 @@ static int aio_poll_wake(struct wait_que
list_del_init(&req->wait.entry);
list_del(&iocb->ki_list);
iocb->ki_res.res = mangle_poll(mask);
- if (iocb->ki_eventfd && eventfd_signal_allowed()) {
+ if (iocb->ki_eventfd && !eventfd_signal_allowed()) {
iocb = NULL;
INIT_WORK(&req->work, aio_poll_put_work);
schedule_work(&req->work);