| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 053/152] io_uring: dont take files/mm for a dead task | Date | Mon, 18 Jan 2021 12:33:48 +0100 |
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From: Pavel Begunkov <asml.silence@gmail.com>
[ Upstream commit 621fadc22365f3cf307bcd9048e3372e9ee9cdcc ]
In rare cases a task may be exiting while io_ring_exit_work() trying to cancel/wait its requests. It's ok for __io_sq_thread_acquire_mm() because of SQPOLL check, but is not for __io_sq_thread_acquire_files(). Play safe and fail for both of them.
Cc: stable@vger.kernel.org # 5.5+ Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> --- fs/io_uring.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 4833b68f1a1cc..6c356b9e87b39 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1009,6 +1009,8 @@ static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx) { struct mm_struct *mm; + if (current->flags & PF_EXITING) + return -EFAULT; if (current->mm) return 0; -- 2.27.0
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