Rework the SCLP boundary check to account for different SCLP commands
(eventually) allowing different boundary sizes.
Signed-off-by: Collin Walling
Acked-by: Janosch Frank
Reviewed-by: Cornelia Huck
---
hw/s390x/sclp.c | 19 ++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index 28b973de8f..a37cfbf534 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -49,6 +49,18 @@ static inline bool sclp_command_code_valid(uint32_t code)
return false;
}
+static bool sccb_verify_boundary(uint64_t sccb_addr, uint16_t sccb_len)
+{
+uint64_t sccb_max_addr = sccb_addr + sccb_len - 1;
+uint64_t sccb_boundary = (sccb_addr & PAGE_MASK) + PAGE_SIZE;
+
+if (sccb_max_addr < sccb_boundary) {
+return true;
+}
+
+return false;
+}
+
static void prepare_cpu_entries(MachineState *ms, CPUEntry *entry, int *count)
{
uint8_t features[SCCB_CPU_FEATURE_LEN] = { 0 };
@@ -229,6 +241,11 @@ int sclp_service_call_protected(CPUS390XState *env,
uint64_t sccb,
goto out_write;
}
+if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb.h.length))) {
+work_sccb.h.response_code =
cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
+goto out_write;
+}
+
sclp_c->execute(sclp, &work_sccb, code);
out_write:
s390_cpu_pv_mem_write(env_archcpu(env), 0, &work_sccb,
@@ -274,7 +291,7 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb,
uint32_t code)
goto out_write;
}
-if ((sccb + be16_to_cpu(work_sccb.h.length)) > ((sccb & PAGE_MASK) +
PAGE_SIZE)) {
+if (!sccb_verify_boundary(sccb, be16_to_cpu(work_sccb.h.length))) {
work_sccb.h.response_code =
cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
goto out_write;
}
--
2.26.2
