This is a note to let you know that I've just added the patch titled
nvme: use kref_get_unless_zero in nvme_find_get_ns
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: nvme-use-kref_get_unless_zero-in-nvme_find_get_ns.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Mon Dec 18 14:12:35 CET 2017
From: Christoph Hellwig hch@lst.de Date: Wed, 18 Oct 2017 13:20:01 +0200 Subject: nvme: use kref_get_unless_zero in nvme_find_get_ns
From: Christoph Hellwig hch@lst.de
[ Upstream commit 2dd4122854f697afc777582d18548dded03ce5dd ]
For kref_get_unless_zero to protect against lookup vs free races we need to use it in all places where we aren't guaranteed to already hold a reference. There is no such guarantee in nvme_find_get_ns, so switch to kref_get_unless_zero in this function.
Signed-off-by: Christoph Hellwig hch@lst.de Reviewed-by: Sagi Grimberg sagi@grimberg.me Reviewed-by: Hannes Reinecke hare@suse.com Reviewed-by: Johannes Thumshirn jthumshirn@suse.de Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/nvme/host/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1619,7 +1619,8 @@ static struct nvme_ns *nvme_find_get_ns( mutex_lock(&ctrl->namespaces_mutex); list_for_each_entry(ns, &ctrl->namespaces, list) { if (ns->ns_id == nsid) { - kref_get(&ns->kref); + if (!kref_get_unless_zero(&ns->kref)) + continue; ret = ns; break; }
Patches currently in stable-queue which might be from hch@lst.de are
queue-4.9/xfs-fix-incorrect-extent-state-in-xfs_bmap_add_extent_unwritten_real.patch queue-4.9/nvmet-confirm-sq-percpu-has-scheduled-and-switched-to-atomic.patch queue-4.9/nvme-use-kref_get_unless_zero-in-nvme_find_get_ns.patch queue-4.9/target-iscsi-fix-a-race-condition-in-iscsit_add_reject_from_cmd.patch queue-4.9/nvme-loop-fix-a-possible-use-after-free-when-destroying-the-admin-queue.patch queue-4.9/nvmet-rdma-fix-a-possible-uninitialized-variable-dereference.patch