diff --git a/target/mips/tcg/sysemu/mips-semi.c b/target/mips/tcg/sysemu/mips-semi.c
index 5fb1ad9092..85f0567a7f 100644
--- a/target/mips/tcg/sysemu/mips-semi.c
+++ b/target/mips/tcg/sysemu/mips-semi.c
@@ -321,6 +321,9 @@ void mips_semihosting(CPUMIPSState *env)
             if (use_gdb_syscalls()) {
                 addr = gpr[29] - str->len;
                 p = lock_user(VERIFY_WRITE, addr, str->len, 0);
+                if (!p) {
+                    report_fault(env);
+                }
                 memcpy(p, str->str, str->len);
                 unlock_user(p, addr, str->len);
                 semihost_sys_write(cs, uhi_cb, 2, addr, str->len);