Re: [PATCH v3] target/ppc: Add lower bound check for watchdogNumber

[Chinmay Rath]

On 8/18/26 16:15, Chinmay Rath wrote:

Add missing lower bound check for H_WATCHDOG H_CALL's watchdogNumber parameter
as per PAPR documentation ver 12.10.00 section 14.15.5 'H_WATCHDOG'.

Closes : https://gitlab.com/qemu-project/qemu/-/work_items/3600
Reviewed-by: Amit Machhiwal <amach...@linux.ibm.com>

Reported-by: huntr bubble <bubblehu...@gmail.com>

Signed-off-by: Chinmay Rath <ra...@linux.ibm.com>
---

Changes from v2:
Renamed watchdogNumber_valid to watchdog_number_valid - Amit
Retained Amit's Reviewed-by

  hw/watchdog/spapr_watchdog.c | 16 +++++++++++-----
  1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/hw/watchdog/spapr_watchdog.c b/hw/watchdog/spapr_watchdog.c
index 5b3f50de3a..5a72896066 100644
--- a/hw/watchdog/spapr_watchdog.c
+++ b/hw/watchdog/spapr_watchdog.c
@@ -127,6 +127,12 @@ static void watchdog_expired(void *pw)
      }
  }

+static inline bool watchdog_number_valid(target_ulong watchdogNumber,

+                                        SpaprMachineState *spapr)
+{
+    return watchdogNumber >= 1 && watchdogNumber <= ARRAY_SIZE(spapr->wds);
+}
+
  static target_ulong h_watchdog(PowerPCCPU *cpu,
                                 SpaprMachineState *spapr,
                                 target_ulong opcode, target_ulong *args)
@@ -145,7 +151,7 @@ static target_ulong h_watchdog(PowerPCCPU *cpu,

switch (operation) {

      case PSERIES_WDTF_OP_START:
-        if (watchdogNumber > ARRAY_SIZE(spapr->wds)) {
+        if (!watchdog_number_valid(watchdogNumber, spapr)) {
              return H_P2;
          }
          if (timeoutInMs <= WDT_MIN_TIMEOUT) {
@@ -170,11 +176,11 @@ static target_ulong h_watchdog(PowerPCCPU *cpu,
      case PSERIES_WDTF_OP_STOP:
          if (watchdogNumber == PSERIES_WDT_STOP_ALL) {
              ret = watchdog_stop_all(spapr);
-        } else if (watchdogNumber <= ARRAY_SIZE(spapr->wds)) {
+        } else if (!watchdog_number_valid(watchdogNumber, spapr)) {
+            return H_P2;
+        } else {
              ret = watchdog_stop(watchdogNumber,
                                  &spapr->wds[watchdogNumber - 1]);
-        } else {
-            return H_P2;
          }
          break;
      case PSERIES_WDTF_OP_QUERY:
@@ -184,7 +190,7 @@ static target_ulong h_watchdog(PowerPCCPU *cpu,
          trace_spapr_watchdog_query(args[0]);
          break;
      case PSERIES_WDTF_OP_QUERY_LPM:
-        if (watchdogNumber > ARRAY_SIZE(spapr->wds)) {
+        if (!watchdog_number_valid(watchdogNumber, spapr)) {
              return H_P2;
          }
          args[0] = PSERIES_WDTQL_QUERY_NOT_STOPPED;