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authorPavel Begunkov <asml.silence@gmail.com>2019-10-25 12:31:31 +0300
committerJens Axboe <axboe@kernel.dk>2019-10-25 09:02:01 -0600
commit935d1e45908afb8853c497f2c2bbbb685dec51dc (patch)
tree408e5c91fcd34aaa19d71fb4c672d89bf3e9c756
parentfb5ccc98782f654778cb8d96ba8a998304f9a51f (diff)
downloadlinux-935d1e45908afb8853c497f2c2bbbb685dec51dc.tar.bz2
io_uring: Fix race for sqes with userspace
io_ring_submit() finalises with 1. io_commit_sqring(), which releases sqes to the userspace 2. Then calls to io_queue_link_head(), accessing released head's sqe Reorder them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--fs/io_uring.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 949c82a40d16..32f6598ecae9 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2795,13 +2795,14 @@ out:
submit++;
io_submit_sqe(ctx, &s, statep, &link);
}
- io_commit_sqring(ctx);
if (link)
io_queue_link_head(ctx, link, &link->submit, shadow_req);
if (statep)
io_submit_state_end(statep);
+ io_commit_sqring(ctx);
+
return submit;
}