6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jack Morgenstein jackm@nvidia.com
[ Upstream commit 92a251c3df8ea1991cd9fe00f1ab0cfce18d7711 ]
The cited commit fixed a crash when cma_netevent_callback was called for a cma_id while work on that id from a previous call had not yet started. The work item was re-initialized in the second call, which corrupted the work item currently in the work queue.
However, it left a problem when queue_work fails (because the item is still pending in the work queue from a previous call). In this case, cma_id_put (which is called in the work handler) is therefore not called. This results in a userspace process hang (zombie process).
Fix this by calling cma_id_put() if queue_work fails.
Fixes: 45f5dcdd0497 ("RDMA/cma: Fix workqueue crash in cma_netevent_work_handler") Link: https://patch.msgid.link/r/4f3640b501e48d0166f312a64fdadf72b059bd04.17478271... Signed-off-by: Jack Morgenstein jackm@nvidia.com Signed-off-by: Feng Liu feliu@nvidia.com Reviewed-by: Vlad Dumitrescu vdumitrescu@nvidia.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Reviewed-by: Sharath Srinivasan sharath.srinivasan@oracle.com Reviewed-by: Kalesh AP kalesh-anakkur.purayil@broadcom.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/core/cma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index bb3c361bd8d45..0b2cb31d0f999 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -5190,7 +5190,8 @@ static int cma_netevent_callback(struct notifier_block *self, neigh->ha, ETH_ALEN)) continue; cma_id_get(current_id); - queue_work(cma_wq, ¤t_id->id.net_work); + if (!queue_work(cma_wq, ¤t_id->id.net_work)) + cma_id_put(current_id); } out: spin_unlock_irqrestore(&id_table_lock, flags);