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

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

[Chinmay Rath]

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 <amachhiw@linux.ibm.com>
Signed-off-by: Chinmay Rath <rathc@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;
-- 
2.55.0

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 <amachhiw@linux.ibm.com>
Reported-by: huntr bubble <bubblehuntr@gmail.com>
> Signed-off-by: Chinmay Rath <rathc@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;