* [PATCH] io_uring: prevent speculating sq_array indexing
@ 2024-11-04 12:02 Pavel Begunkov
2024-11-04 16:19 ` Jens Axboe
0 siblings, 1 reply; 2+ messages in thread
From: Pavel Begunkov @ 2024-11-04 12:02 UTC (permalink / raw)
To: io-uring; +Cc: Jens Axboe, asml.silence
The SQ index array consists of user provided indexes, which io_uring
then uses to index the SQ, and so it's susceptible to speculation. For
all other queues io_uring tracks heads and tails in kernel, and they
shouldn't need any special care.
Signed-off-by: Pavel Begunkov <[email protected]>
---
io_uring/io_uring.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index f34fa1ead2cf..406825d000eb 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2544,6 +2544,7 @@ static bool io_get_sqe(struct io_ring_ctx *ctx, const struct io_uring_sqe **sqe)
READ_ONCE(ctx->rings->sq_dropped) + 1);
return false;
}
+ head = array_index_nospec(head, ctx->sq_entries);
}
/*
--
2.46.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] io_uring: prevent speculating sq_array indexing
2024-11-04 12:02 [PATCH] io_uring: prevent speculating sq_array indexing Pavel Begunkov
@ 2024-11-04 16:19 ` Jens Axboe
0 siblings, 0 replies; 2+ messages in thread
From: Jens Axboe @ 2024-11-04 16:19 UTC (permalink / raw)
To: io-uring, Pavel Begunkov
On Mon, 04 Nov 2024 12:02:47 +0000, Pavel Begunkov wrote:
> The SQ index array consists of user provided indexes, which io_uring
> then uses to index the SQ, and so it's susceptible to speculation. For
> all other queues io_uring tracks heads and tails in kernel, and they
> shouldn't need any special care.
>
>
Applied, thanks!
[1/1] io_uring: prevent speculating sq_array indexing
commit: 16a6e0430fcfb38e80477a72079c84c612457e91
Best regards,
--
Jens Axboe
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2024-11-04 16:19 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-11-04 12:02 [PATCH] io_uring: prevent speculating sq_array indexing Pavel Begunkov
2024-11-04 16:19 ` Jens Axboe
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox