5.10-stable patches

added patches:
	io_uring-fix-wqe-lock-completion_lock-deadlock.patch

diff --git a/queue-5.10/io_uring-fix-wqe-lock-completion_lock-deadlock.patch b/queue-5.10/io_uring-fix-wqe-lock-completion_lock-deadlock.patch
new file mode 100644 (file)
index 0000000..fe5fe7e
--- /dev/null
+++ b/queue-5.10/io_uring-fix-wqe-lock-completion_lock-deadlock.patch
@@ -0,0 +1,72 @@
+From 907d1df30a51cc1a1d25414a00cde0494b83df7b Mon Sep 17 00:00:00 2001
+From: Pavel Begunkov <asml.silence@gmail.com>
+Date: Tue, 26 Jan 2021 23:35:10 +0000
+Subject: io_uring: fix wqe->lock/completion_lock deadlock
+
+From: Pavel Begunkov <asml.silence@gmail.com>
+
+commit 907d1df30a51cc1a1d25414a00cde0494b83df7b upstream.
+
+Joseph reports following deadlock:
+
+CPU0:
+...
+io_kill_linked_timeout  // &ctx->completion_lock
+io_commit_cqring
+__io_queue_deferred
+__io_queue_async_work
+io_wq_enqueue
+io_wqe_enqueue  // &wqe->lock
+
+CPU1:
+...
+__io_uring_files_cancel
+io_wq_cancel_cb
+io_wqe_cancel_pending_work  // &wqe->lock
+io_cancel_task_cb  // &ctx->completion_lock
+
+Only __io_queue_deferred() calls queue_async_work() while holding
+ctx->completion_lock, enqueue drained requests via io_req_task_queue()
+instead.
+
+Cc: stable@vger.kernel.org # 5.9+
+Reported-by: Joseph Qi <joseph.qi@linux.alibaba.com>
+Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
+Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/io_uring.c |   10 ++--------
+ 1 file changed, 2 insertions(+), 8 deletions(-)
+
+--- a/fs/io_uring.c
++++ b/fs/io_uring.c
+@@ -972,6 +972,7 @@ static int io_setup_async_rw(struct io_k
+                            const struct iovec *fast_iov,
+                            struct iov_iter *iter, bool force);
+ static void io_req_drop_files(struct io_kiocb *req);
++static void io_req_task_queue(struct io_kiocb *req);
+ 
+ static struct kmem_cache *req_cachep;
+ 
+@@ -1502,18 +1503,11 @@ static void __io_queue_deferred(struct i
+       do {
+               struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
+                                               struct io_defer_entry, list);
+-              struct io_kiocb *link;
+ 
+               if (req_need_defer(de->req, de->seq))
+                       break;
+               list_del_init(&de->list);
+-              /* punt-init is done before queueing for defer */
+-              link = __io_queue_async_work(de->req);
+-              if (link) {
+-                      __io_queue_linked_timeout(link);
+-                      /* drop submission reference */
+-                      io_put_req_deferred(link, 1);
+-              }
++              io_req_task_queue(de->req);
+               kfree(de);
+       } while (!list_empty(&ctx->defer_list));
+ }

diff --git a/queue-5.10/series b/queue-5.10/series
index c9dbe881254f153b9417ec9e69b76f5e068e2097..afdc21069f362b4a31db2df78bad534d0f09b6da 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -44,3 +44,4 @@ kvm-x86-allow-kvm_req_get_nested_state_pages-outside-guest-mode-for-vmx.patch
 kvm-nvmx-sync-unsync-d-vmcs02-state-to-vmcs12-on-migration.patch
 kvm-x86-get-smi-pending-status-correctly.patch
 kvm-forbid-the-use-of-tagged-userspace-addresses-for-memslots.patch
+io_uring-fix-wqe-lock-completion_lock-deadlock.patch