6.6-stable review patch. If anyone has any objections, please let me know.
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From: Nicolin Chen nicolinc@nvidia.com
commit b23e09f9997771b4b739c1c694fa832b5fa2de02 upstream.
There are callers that read the unmapped bytes even when rc != 0. Thus, do not forget to report it in the error path too.
Fixes: 8d40205f6093 ("iommufd: Add kAPI toward external drivers for kernel access") Link: https://patch.msgid.link/r/e2b61303bbc008ba1a4e2d7c2a2894749b59fdac.17521267... Cc: stable@vger.kernel.org Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/iommufd/io_pagetable.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -524,8 +524,10 @@ again: iommufd_access_notify_unmap(iopt, area_first, length); /* Something is not responding to unmap requests. */ tries++; - if (WARN_ON(tries > 100)) - return -EDEADLOCK; + if (WARN_ON(tries > 100)) { + rc = -EDEADLOCK; + goto out_unmapped; + } goto again; }
@@ -547,6 +549,7 @@ again: out_unlock_iova: up_write(&iopt->iova_rwsem); up_read(&iopt->domains_rwsem); +out_unmapped: if (unmapped) *unmapped = unmapped_bytes; return rc;