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[4/5] hw/i2c: pmbus: block uninitialised string reads

Message ID 20230322175513.1550412-5-titusr@google.com
State New
Headers show
Series PMBus fixes and new functions | expand

Commit Message

Titus Rwantare March 22, 2023, 5:55 p.m. UTC 
Devices models calling pmbus_send_string can't be relied upon to
send a non-zero pointer. This logs an error and doesn't segfault.

Reviewed-by: Patrick Venture <venture@google.com>
Signed-off-by: Titus Rwantare <titusr@google.com>
---
 hw/i2c/pmbus_device.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Philippe Mathieu-Daudé March 29, 2023, 2:15 p.m. UTC | #1 
On 22/3/23 18:55, Titus Rwantare wrote:
> Devices models calling pmbus_send_string can't be relied upon to
> send a non-zero pointer. This logs an error and doesn't segfault.
> 
> Reviewed-by: Patrick Venture <venture@google.com>
> Signed-off-by: Titus Rwantare <titusr@google.com>
> ---
>   hw/i2c/pmbus_device.c | 7 +++++++
>   1 file changed, 7 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Corey Minyard March 30, 2023, 4:23 p.m. UTC | #2 
On Wed, Mar 22, 2023 at 05:55:12PM +0000, Titus Rwantare wrote:
> Devices models calling pmbus_send_string can't be relied upon to
> send a non-zero pointer. This logs an error and doesn't segfault.

Yes, a good idea.

Acked-by: Corey Minyard <cminyard@mvista.com>

> 
> Reviewed-by: Patrick Venture <venture@google.com>
> Signed-off-by: Titus Rwantare <titusr@google.com>
> ---
>  hw/i2c/pmbus_device.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/hw/i2c/pmbus_device.c b/hw/i2c/pmbus_device.c
> index bb42e410b4..18e629eaac 100644
> --- a/hw/i2c/pmbus_device.c
> +++ b/hw/i2c/pmbus_device.c
> @@ -94,6 +94,13 @@ void pmbus_send64(PMBusDevice *pmdev, uint64_t data)
>  
>  void pmbus_send_string(PMBusDevice *pmdev, const char *data)
>  {
> +    if (!data) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: %s: uninitialised read from 0x%02x\n",
> +                      __func__, DEVICE(pmdev)->canonical_path, pmdev->code);
> +        return;
> +    }
> +
>      size_t len = strlen(data);
>      g_assert(len + pmdev->out_buf_len < SMBUS_DATA_MAX_LEN);
>      pmdev->out_buf[len + pmdev->out_buf_len] = len;
> -- 
> 2.40.0.rc1.284.g88254d51c5-goog
>
diff mbox series

Patch

diff --git a/hw/i2c/pmbus_device.c b/hw/i2c/pmbus_device.c
index bb42e410b4..18e629eaac 100644
--- a/hw/i2c/pmbus_device.c
+++ b/hw/i2c/pmbus_device.c
@@ -94,6 +94,13 @@  void pmbus_send64(PMBusDevice *pmdev, uint64_t data)
 
 void pmbus_send_string(PMBusDevice *pmdev, const char *data)
 {
+    if (!data) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: %s: uninitialised read from 0x%02x\n",
+                      __func__, DEVICE(pmdev)->canonical_path, pmdev->code);
+        return;
+    }
+
     size_t len = strlen(data);
     g_assert(len + pmdev->out_buf_len < SMBUS_DATA_MAX_LEN);
     pmdev->out_buf[len + pmdev->out_buf_len] = len;