Commit b3060198 authored by Artem Sadovnikov's avatar Artem Sadovnikov Committed by Alex Williamson
Browse files

vfio/mlx5: fix possible overflow in tracking max message size 



MLX cap pg_track_log_max_msg_size consists of 5 bits, value of which is
used as power of 2 for max_msg_size. This can lead to multiplication
overflow between max_msg_size (u32) and integer constant, and afterwards
incorrect value is being written to rq_size.

Fix this issue by extending integer constant to u64 type.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Suggested-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarArtem Sadovnikov <a.sadovnikov@ispras.ru>
Reviewed-by: default avatarYishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20250701144017.2410-2-a.sadovnikov@ispras.ru


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent e908f58b

drivers/vfio/pci/mlx5/cmd.c

+2 −2
Original line number Diff line number Diff line
@@ -1523,8 +1523,8 @@ int mlx5vf_start_page_tracker(struct vfio_device *vdev, 
	log_max_msg_size = MLX5_CAP_ADV_VIRTUALIZATION(mdev, pg_track_log_max_msg_size);

	max_msg_size = (1ULL << log_max_msg_size);

	/* The RQ must hold at least 4 WQEs/messages for successful QP creation */

	if (rq_size < 4 * max_msg_size)

		rq_size = 4 * max_msg_size;

	if (rq_size < 4ULL * max_msg_size)

		rq_size = 4ULL * max_msg_size;



	memset(tracker, 0, sizeof(*tracker));

	tracker->uar = mlx5_get_uars_page(mdev);