This is a note to let you know that I've just added the patch titled

RDMA/ucma: Fix use-after-free access in ucma_close

to the 4.4-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: rdma-ucma-fix-use-after-free-access-in-ucma_close.patch and it can be found in the queue-4.4 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 ed65a4dc22083e73bac599ded6a262318cad7baf Mon Sep 17 00:00:00 2001

From: Leon Romanovsky leonro@mellanox.com Date: Mon, 19 Mar 2018 14:20:15 +0200 Subject: RDMA/ucma: Fix use-after-free access in ucma_close

From: Leon Romanovsky leonro@mellanox.com

commit ed65a4dc22083e73bac599ded6a262318cad7baf upstream.

The error in ucma_create_id() left ctx in the list of contexts belong to ucma file descriptor. The attempt to close this file descriptor causes to use-after-free accesses while iterating over such list.

Fixes: 75216638572f ("RDMA/cma: Export rdma cm interface to userspace") Reported-by: syzbot+dcfd344365a56fbebd0f@syzkaller.appspotmail.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Reviewed-by: Sean Hefty sean.hefty@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/infiniband/core/ucma.c | 3 +++ 1 file changed, 3 insertions(+)

--- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -494,6 +494,9 @@ err1: mutex_lock(&mut); idr_remove(&ctx_idr, ctx->id); mutex_unlock(&mut); + mutex_lock(&file->mut); + list_del(&ctx->list); + mutex_unlock(&file->mut); kfree(ctx); return ret; }

Patches currently in stable-queue which might be from leonro@mellanox.com are

queue-4.4/rdma-ucma-check-af-family-prior-resolving-address.patch queue-4.4/rdma-ucma-don-t-allow-join-attempts-for-unsupported-af-family.patch queue-4.4/rdma-ucma-check-that-device-is-connected-prior-to-access-it.patch queue-4.4/rdma-ucma-fix-use-after-free-access-in-ucma_close.patch queue-4.4/rdma-ucma-ensure-that-cm_id-exists-prior-to-access-it.patch queue-4.4/rdma-ucma-check-that-device-exists-prior-to-accessing-it.patch