IB/srp: Enforce protocol limit on srp_sg_tablesize
The current SRP initiator will allow unlimited s/g entries in the
indirect descriptors lists, but the entry count field in the SRP_CMD
request is 8 bits, so setting srp_sg_tablesize too large will open the
possibility of wrapping the count and generating invalid requests.
Clamp srp_sg_tablesize to the protocol limits to prevent surprises.
Reported by Martin W. Schlining III <mschlining@datadirectnet.com>.
Signed-off-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index fd4a49f..125765a 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -68,7 +68,7 @@
module_param(srp_sg_tablesize, int, 0444);
MODULE_PARM_DESC(srp_sg_tablesize,
- "Max number of gather/scatter entries per I/O (default is 12)");
+ "Max number of gather/scatter entries per I/O (default is 12, max 255)");
static int topspin_workarounds = 1;
@@ -2138,6 +2138,11 @@
{
int ret;
+ if (srp_sg_tablesize > 255) {
+ printk(KERN_WARNING PFX "Clamping srp_sg_tablesize to 255\n");
+ srp_sg_tablesize = 255;
+ }
+
ib_srp_transport_template =
srp_attach_transport(&ib_srp_transport_functions);
if (!ib_srp_transport_template)