From: Dennis Dalessandro dennis.dalessandro@cornelisnetworks.com
commit f93e91a0372c922c20d5bee260b0f43b4b8a1bee upstream.
When multiplying of different types, an overflow is possible even when storing the result in a larger type. This is because the conversion is done after the multiplication. So arithmetic overflow and thus in incorrect value is possible.
Correct an instance of this in the inter packet delay calculation. Fix by ensuring one of the operands is u64 which will promote the other to u64 as well ensuring no overflow.
Cc: stable@vger.kernel.org Fixes: 7724105686e7 ("IB/hfi1: add driver files") Link: https://lore.kernel.org/r/20220520183712.48973.29855.stgit@awfm-01.cornelisn... Reviewed-by: Mike Marciniszyn mike.marciniszyn@cornelisnetworks.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@cornelisnetworks.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/hw/hfi1/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/infiniband/hw/hfi1/init.c +++ b/drivers/infiniband/hw/hfi1/init.c @@ -543,7 +543,7 @@ void set_link_ipg(struct hfi1_pportdata u16 shift, mult; u64 src; u32 current_egress_rate; /* Mbits /sec */ - u32 max_pkt_time; + u64 max_pkt_time; /* * max_pkt_time is the maximum packet egress time in units * of the fabric clock period 1/(805 MHz).