kevin/linux
1
Fork 0
Code

io_uring/net: harden multishot termination case for recv

Browse Source 
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: b3fdea6ecb ("io_uring: multishot recv")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2024-09-26 07:08:10 -06:00
parent 17ea56b752
commit c314094cb4
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
io_uring/net.c
View File

@ -1133,6 +1133,7 @@ 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))
@ -1187,6 +1188,7 @@ out_free:
req_set_fail(req);
}
mshot_finished = ret <= 0;
if (ret > 0)
ret += sr->done_io;
else if (sr->done_io)
@ -1194,7 +1196,7 @@ out_free:
else
io_kbuf_recycle(req, issue_flags);
if (!io_recv_finish(req, &ret, kmsg, ret <= 0, issue_flags))
if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
goto retry_multishot;
return ret;