From: Nicolin Chen Date: Fri, 22 May 2026 00:36:32 +0000 (-0700) Subject: iommufd: Fix data_len byte-count vs element-count mismatch X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=85345becfead3255a5f875d4b4d82ea01d926239;p=thirdparty%2Flinux.git 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 --- diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 6ac1965199e9a..43fbc5bed8de3 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) \