msm: ipa3: Check channel in right state before access base address

Observing use after free issue during teardown WAN pipe if we
receive the incoming packet. Adding check channel in right state
before access base address.

Change-Id: I29a611693b78637811fe45abea93d9ed3e6f54e5
Signed-off-by: Ashok Vuyyuru <[email protected]>

drivers/platform/msm/gsi/gsi.c

@@ -3850,6 +3850,11 @@ int __gsi_populate_tre(struct gsi_chan_ctx *ctx,
 	tre.ieob = (xfer->flags & GSI_XFER_FLAG_EOB) ? 1 : 0;
 	tre.chain = (xfer->flags & GSI_XFER_FLAG_CHAIN) ? 1 : 0;
 
+	if (unlikely(ctx->state  == GSI_CHAN_STATE_NOT_ALLOCATED)) {
+		GSIERR("bad state %d\n", ctx->state);
+		return -GSI_STATUS_UNSUPPORTED_OP;
+	}
+
 	idx = gsi_find_idx_from_addr(&ctx->ring, ctx->ring.wp_local);
 	tre_ptr = (struct gsi_tre *)(ctx->ring.base_va +
 		idx * ctx->ring.elem_sz);