IB/srp: Fix use-after-free in srp_reset_req()

commit 9b796d06d5d1b1e85ae2316a283ea11dd739ef96 upstream.

srp_free_req() uses the scsi_cmnd structure contents to unmap
buffers, so we must invoke srp_free_req() before we release
ownership of that structure.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index c76b051..b3ead13 100644 (file)
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -620,9 +620,9 @@ static void srp_reset_req(struct srp_target_port *target, struct srp_request *re
        struct scsi_cmnd *scmnd = srp_claim_req(target, req, NULL);
 
        if (scmnd) {
+               srp_free_req(target, req, scmnd, 0);
                scmnd->result = DID_RESET << 16;
                scmnd->scsi_done(scmnd);
-               srp_free_req(target, req, scmnd, 0);
        }
 }