[PATCH 4.19 20/90] IB/hfi1: Validate fault injection opcode user input

[Greg Kroah-Hartman]

From: Kaike Wan <kaike.wan@xxxxxxxxx>

commit 5f90677ed31963abb184ee08ebee4a4a68225dd8 upstream.

The opcode range for fault injection from user should be validated before
it is applied to the fault->opcodes[] bitmap to avoid out-of-bound
error.

Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: a74d5307caba ("IB/hfi1: Rework fault injection machinery")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Kaike Wan <kaike.wan@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/hw/hfi1/fault.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/infiniband/hw/hfi1/fault.c
+++ b/drivers/infiniband/hw/hfi1/fault.c
@@ -153,6 +153,7 @@ static ssize_t fault_opcodes_write(struc
 		char *dash;
 		unsigned long range_start, range_end, i;
 		bool remove = false;
+		unsigned long bound = 1U << BITS_PER_BYTE;
 
 		end = strchr(ptr, ',');
 		if (end)
@@ -178,6 +179,10 @@ static ssize_t fault_opcodes_write(struc
 				    BITS_PER_BYTE);
 			break;
 		}
+		/* Check the inputs */
+		if (range_start >= bound || range_end >= bound)
+			break;
+
 		for (i = range_start; i <= range_end; i++) {
 			if (remove)
 				clear_bit(i, fault->opcodes);