6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jens Axboe axboe@kernel.dk
[ Upstream commit c314094cb4cfa6fc5a17f4881ead2dfebfa717a7 ]
If the recv returns zero, or an error, then it doesn't matter if more data has already been received for this buffer. A condition like that should terminate the multishot receive. Rather than pass in the collected return value, pass in whether to terminate or keep the recv going separately.
Note that this isn't a bug right now, as the only way to get there is via setting MSG_WAITALL with multishot receive. And if an application does that, then -EINVAL is returned anyway. But it seems like an easy bug to introduce, so let's make it a bit more explicit.
Link: https://github.com/axboe/liburing/issues/1246 Cc: stable@vger.kernel.org Fixes: b3fdea6ecb55 ("io_uring: multishot recv") Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- io_uring/net.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/io_uring/net.c b/io_uring/net.c index 48404bd330017..f41acabf7b4a5 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -893,6 +893,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) int ret, min_ret = 0; bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; size_t len = sr->len; + bool mshot_finished;
if (!(req->flags & REQ_F_POLLED) && (sr->flags & IORING_RECVSEND_POLL_FIRST)) @@ -957,6 +958,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) req_set_fail(req); }
+ mshot_finished = ret <= 0; if (ret > 0) ret += sr->done_io; else if (sr->done_io) @@ -968,7 +970,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) if (msg.msg_inq) cflags |= IORING_CQE_F_SOCK_NONEMPTY;
- if (!io_recv_finish(req, &ret, cflags, ret <= 0, issue_flags)) + if (!io_recv_finish(req, &ret, cflags, mshot_finished, issue_flags)) goto retry_multishot;
return ret;