From: Jason Gunthorpe jgg@mellanox.com
commit 6b3712c0246ca7b2b8fa05eab2362cf267410f7e upstream.
The set of entry->driver_removed is missing locking, protect it with xa_lock() which is held by the only reader.
Otherwise readers may continue to see driver_removed = false after rdma_user_mmap_entry_remove() returns and may continue to try and establish new mmaps.
Fixes: 3411f9f01b76 ("RDMA/core: Create mmap database and cookie helper functions") Link: https://lore.kernel.org/r/20200115202041.GA17199@ziepe.ca Reviewed-by: Gal Pressman galpress@amazon.com Acked-by: Michal Kalderon michal.kalderon@marvell.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/ib_core_uverbs.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/infiniband/core/ib_core_uverbs.c +++ b/drivers/infiniband/core/ib_core_uverbs.c @@ -232,7 +232,9 @@ void rdma_user_mmap_entry_remove(struct if (!entry) return;
+ xa_lock(&entry->ucontext->mmap_xa); entry->driver_removed = true; + xa_unlock(&entry->ucontext->mmap_xa); kref_put(&entry->ref, rdma_user_mmap_entry_free); } EXPORT_SYMBOL(rdma_user_mmap_entry_remove);