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From febb985c06cb6f5fac63598c0bffd4fd823d110d Mon Sep 17 00:00:00 2001 |
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From: Jens Axboe <axboe@kernel.dk> |
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Date: Mon, 9 Jan 2023 14:46:10 -0700 |
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Subject: io_uring/poll: add hash if ready poll request can't complete inline |
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|
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From: Jens Axboe <axboe@kernel.dk> |
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|
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commit febb985c06cb6f5fac63598c0bffd4fd823d110d upstream. |
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|
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If we don't, then we may lose access to it completely, leading to a |
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request leak. This will eventually stall the ring exit process as |
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well. |
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|
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Cc: stable@vger.kernel.org |
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Fixes: 49f1c68e048f ("io_uring: optimise submission side poll_refs") |
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Reported-and-tested-by: syzbot+6c95df01470a47fc3af4@syzkaller.appspotmail.com |
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Link: https://lore.kernel.org/io-uring/0000000000009f829805f1ce87b2@google.com/ |
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Suggested-by: Pavel Begunkov <asml.silence@gmail.com> |
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Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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--- |
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io_uring/poll.c | 17 ++++++++++++----- |
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1 file changed, 12 insertions(+), 5 deletions(-) |
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|
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--- a/io_uring/poll.c |
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+++ b/io_uring/poll.c |
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@@ -549,6 +549,14 @@ static bool io_poll_can_finish_inline(st |
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return pt->owning || io_poll_get_ownership(req); |
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} |
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|
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+static void io_poll_add_hash(struct io_kiocb *req) |
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+{ |
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+ if (req->flags & REQ_F_HASH_LOCKED) |
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+ io_poll_req_insert_locked(req); |
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+ else |
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+ io_poll_req_insert(req); |
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+} |
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+ |
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/* |
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* Returns 0 when it's handed over for polling. The caller owns the requests if |
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* it returns non-zero, but otherwise should not touch it. Negative values |
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@@ -607,18 +615,17 @@ static int __io_arm_poll_handler(struct |
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|
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if (mask && |
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((poll->events & (EPOLLET|EPOLLONESHOT)) == (EPOLLET|EPOLLONESHOT))) { |
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- if (!io_poll_can_finish_inline(req, ipt)) |
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+ if (!io_poll_can_finish_inline(req, ipt)) { |
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+ io_poll_add_hash(req); |
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return 0; |
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+ } |
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io_poll_remove_entries(req); |
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ipt->result_mask = mask; |
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/* no one else has access to the req, forget about the ref */ |
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return 1; |
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} |
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|
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- if (req->flags & REQ_F_HASH_LOCKED) |
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- io_poll_req_insert_locked(req); |
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- else |
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- io_poll_req_insert(req); |
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+ io_poll_add_hash(req); |
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|
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if (mask && (poll->events & EPOLLET) && |
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io_poll_can_finish_inline(req, ipt)) { |
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