From 85345becfead3255a5f875d4b4d82ea01d926239 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Thu, 21 May 2026 17:36:32 -0700 Subject: iommufd: Fix data_len byte-count vs element-count mismatch kzalloc_flex() computes the allocation size. With event_data typed as u64, data_len is interpreted as a u64 element count. Yet, every caller and the read path treat data_len as a byte count. The current code over-allocates by sizeof(u64) and the __counted_by() annotation overstates the length by the same factor. Re-type event_data as u8. No functional change in user-visible behavior. Fixes: e36ba5ab808e ("iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC") Link: https://patch.msgid.link/r/f7665f839b9dce917d6bd394375a1cf56568d86b.1779408671.git.nicolinc@nvidia.com Cc: stable@vger.kernel.org Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/iommufd_private.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 6ac1965199e9..43fbc5bed8de 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -602,7 +602,7 @@ struct iommufd_vevent { struct iommufd_vevent_header header; struct list_head node; /* for iommufd_eventq::deliver */ ssize_t data_len; - u64 event_data[] __counted_by(data_len); + u8 event_data[] __counted_by(data_len); }; #define vevent_for_lost_events_header(vevent) \ -- cgit v1.2.3