[v1] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

[PATCH] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by nhuquynh@tutamail.com 3 weeks, 3 days ago

From 80fd05e6d156d5a90d4908f2498bf6cc7acbdefd Mon Sep 17 00:00:00 2001
From: Bui Nguyen Nhu Quynh <nhuquynh@tutamail.com>
Date: Tue, 1 Sep 2026 19:39:49 +0700
Subject: [PATCH] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

The kvmppc_gsm_refresh_info() function incorrectly checks for the
presence of the fill_info callback instead of refresh_info.

This can lead to:
- NULL pointer dereference if refresh_info is NULL but fill_info is present
- EINVAL return if refresh_info is present but fill_info is NULL

Fix this by checking the correct callback.

Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
Signed-off-by: Bui Nguyen Nhu Quynh <nhuquynh@tutamail.com>
---
arch/powerpc/kvm/guest-state-buffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
index 42843eca6727..aeb586ba4523 100644
--- a/arch/powerpc/kvm/guest-state-buffer.c
+++ b/arch/powerpc/kvm/guest-state-buffer.c
@@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
    struct kvmppc_gs_buff *gsb)
{
-	if (!gsm->ops->fill_info)
+	if (!gsm->ops->refresh_info)
return -EINVAL;
 
return gsm->ops->refresh_info(gsm, gsb);
-- 
2.54.0

Re: [PATCH] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Amit Machhiwal 2 weeks, 5 days ago

On 2026/09/01 03:26 PM, nhuquynh@tutamail.com wrote:
> From 80fd05e6d156d5a90d4908f2498bf6cc7acbdefd Mon Sep 17 00:00:00 2001
> From: Bui Nguyen Nhu Quynh <nhuquynh@tutamail.com>
> Date: Tue, 1 Sep 2026 19:39:49 +0700
> Subject: [PATCH] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info
> 
> The kvmppc_gsm_refresh_info() function incorrectly checks for the
> presence of the fill_info callback instead of refresh_info.
> 
> This can lead to:
> - NULL pointer dereference if refresh_info is NULL but fill_info is present
> - EINVAL return if refresh_info is present but fill_info is NULL
> 
> Fix this by checking the correct callback.
> 
> Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
> Signed-off-by: Bui Nguyen Nhu Quynh <nhuquynh@tutamail.com>
> ---
> arch/powerpc/kvm/guest-state-buffer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
> index 42843eca6727..aeb586ba4523 100644
> --- a/arch/powerpc/kvm/guest-state-buffer.c
> +++ b/arch/powerpc/kvm/guest-state-buffer.c
> @@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
> int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
>     struct kvmppc_gs_buff *gsb)
> {
> -	if (!gsm->ops->fill_info)
> +	if (!gsm->ops->refresh_info)
> return -EINVAL;

Thanks for catching this.

The patch appears corrupted by your email client (whitespace mangling /
quoted-printable encoding).

❯ git apply ./20260901_nhuquynh_kvm_ppc_fix_callback_check_in_kvmppc_gsm_refresh_info.mbx
error: corrupt patch at line 30

Please consider configuring and using git send-email to submit v2.

Thanks,
Amit

>  
> return gsm->ops->refresh_info(gsm, gsb);
> -- 
> 2.54.0

[PATCH v3] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Bui Nguyen Nhu Quynh 1 week ago

The kvmppc_gsm_refresh_info() function incorrectly checks for the
presence of the fill_info callback instead of refresh_info.

This can lead to:
- NULL pointer dereference if refresh_info is NULL but fill_info is present
- EINVAL return if refresh_info is present but fill_info is NULL

Fix this by checking the correct callback.

Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
Signed-off-by: Bui Nguyen Nhu Quynh <kaylovefoss@gmail.com>
---
v3:
- Resend to fix whitespace handling issue on v2. No code changes.

 arch/powerpc/kvm/guest-state-buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
index 42843eca6727..aeb586ba4523 100644
--- a/arch/powerpc/kvm/guest-state-buffer.c
+++ b/arch/powerpc/kvm/guest-state-buffer.c
@@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
 int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
 			    struct kvmppc_gs_buff *gsb)
 {
-	if (!gsm->ops->fill_info)
+	if (!gsm->ops->refresh_info)
 		return -EINVAL;
 
 	return gsm->ops->refresh_info(gsm, gsb);
-- 
2.54.0

Re: [PATCH v3] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Gautam Menghani 5 days ago

On Fri, Sep 18, 2026 at 09:31:24PM +0700, Bui Nguyen Nhu Quynh wrote:
> The kvmppc_gsm_refresh_info() function incorrectly checks for the
> presence of the fill_info callback instead of refresh_info.
> 
> This can lead to:
> - NULL pointer dereference if refresh_info is NULL but fill_info is present
> - EINVAL return if refresh_info is present but fill_info is NULL
> 
> Fix this by checking the correct callback.
> 
> Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
> Signed-off-by: Bui Nguyen Nhu Quynh <kaylovefoss@gmail.com>
> ---
> v3:
> - Resend to fix whitespace handling issue on v2. No code changes.
> 

You missed the v2 changelog here. You should mention all changes
introduced in every version.

>  arch/powerpc/kvm/guest-state-buffer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
> index 42843eca6727..aeb586ba4523 100644
> --- a/arch/powerpc/kvm/guest-state-buffer.c
> +++ b/arch/powerpc/kvm/guest-state-buffer.c
> @@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
>  int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
>  			    struct kvmppc_gs_buff *gsb)
>  {
> -	if (!gsm->ops->fill_info)
> +	if (!gsm->ops->refresh_info)
>  		return -EINVAL;
>  
>  	return gsm->ops->refresh_info(gsm, gsb);
> -- 
> 2.54.0
> 
> 

LGTM, this is a copy paste mistake. I did some quick sanity test with
this patch applied.

Tested-by: Gautam Menghani <gautam@linux.ibm.com>

Re: [PATCH v3] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Amit Machhiwal 1 week ago

On 2026/09/18 09:31 PM, Bui Nguyen Nhu Quynh wrote:
> The kvmppc_gsm_refresh_info() function incorrectly checks for the
> presence of the fill_info callback instead of refresh_info.
> 
> This can lead to:
> - NULL pointer dereference if refresh_info is NULL but fill_info is present
> - EINVAL return if refresh_info is present but fill_info is NULL
> 
> Fix this by checking the correct callback.
> 
> Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
> Signed-off-by: Bui Nguyen Nhu Quynh <kaylovefoss@gmail.com>
> ---
> v3:
> - Resend to fix whitespace handling issue on v2. No code changes.

Thanks for fixing the spacing issues.  The patch applies fine now.

Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>

Thanks,
Amit

> 
>  arch/powerpc/kvm/guest-state-buffer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
> index 42843eca6727..aeb586ba4523 100644
> --- a/arch/powerpc/kvm/guest-state-buffer.c
> +++ b/arch/powerpc/kvm/guest-state-buffer.c
> @@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
>  int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
>  			    struct kvmppc_gs_buff *gsb)
>  {
> -	if (!gsm->ops->fill_info)
> +	if (!gsm->ops->refresh_info)
>  		return -EINVAL;
>  
>  	return gsm->ops->refresh_info(gsm, gsb);
> -- 
> 2.54.0
>

[PATCH v2] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Bui Nguyen Nhu Quynh 1 week, 2 days ago

The kvmppc_gsm_refresh_info() function incorrectly checks for the
presence of the fill_info callback instead of refresh_info.

This can lead to:
- NULL pointer dereference if refresh_info is NULL but fill_info is present
- EINVAL return if refresh_info is present but fill_info is NULL

Fix this by checking the correct callback.

Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
Signed-off-by: Bui Nguyen Nhu Quynh <kaylovefoss@gmail.com>
---
v2:
- Resend; v1 was mangled by the mail client. No code changes.

 arch/powerpc/kvm/guest-state-buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
index 42843eca6727..aeb586ba4523 100644
--- a/arch/powerpc/kvm/guest-state-buffer.c
+++ b/arch/powerpc/kvm/guest-state-buffer.c
@@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
 int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
 	struct kvmppc_gs_buff *gsb)
 {
-	if (!gsm->ops->fill_info)
+	if (!gsm->ops->refresh_info)
 	return -EINVAL;
 
 	return gsm->ops->refresh_info(gsm, gsb);
-- 
2.54.0

Re: [PATCH v2] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Amit Machhiwal 1 week, 2 days ago

On 2026/09/16 09:07 PM, Bui Nguyen Nhu Quynh wrote:
> The kvmppc_gsm_refresh_info() function incorrectly checks for the
> presence of the fill_info callback instead of refresh_info.
> 
> This can lead to:
> - NULL pointer dereference if refresh_info is NULL but fill_info is present
> - EINVAL return if refresh_info is present but fill_info is NULL
> 
> Fix this by checking the correct callback.
> 
> Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
> Signed-off-by: Bui Nguyen Nhu Quynh <kaylovefoss@gmail.com>
> ---
> v2:
> - Resend; v1 was mangled by the mail client.  No code changes.
> 
>  arch/powerpc/kvm/guest-state-buffer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
> index 42843eca6727..aeb586ba4523 100644
> --- a/arch/powerpc/kvm/guest-state-buffer.c
> +++ b/arch/powerpc/kvm/guest-state-buffer.c
> @@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
>  int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
>  	struct kvmppc_gs_buff *gsb)

The fix is correct.

However, the patch still does not apply cleanly:

  $ git apply ./v2_...mbx --check --verbose
  error: patch failed: arch/powerpc/kvm/guest-state-buffer.c:598
  error: arch/powerpc/kvm/guest-state-buffer.c: patch does not apply

The index line in the diff (42843eca6727) is a valid blob in the tree, so the
patch base is correct.  The problem is that the context lines in the diff do not
match that blob.  Concretely, the blob at 42843eca6727 has:

  line 599:  \t\t\t    struct kvmppc_gs_buff *gsb)   (3 tabs + 4 spaces)
  line 601:  \t\treturn -EINVAL;                     (2 tabs)

But the patch context has:

  line 599:  \t    struct kvmppc_gs_buff *gsb)        (1 tab + 4 spaces)
  line 601:  \treturn -EINVAL;                        (1 tab)

The indentation on those context lines is being collapsed during patch
generation.  This points to a whitespace handling issue in your git
configuration.

Please review it and then regenerate with git format-patch and verify by
applying the generated patch file onto mainline.  It'll also be a good idea to
rebase your patch on top of mainline before sending v3.

Thanks,
Amit

>  {
> -	if (!gsm->ops->fill_info)
> +	if (!gsm->ops->refresh_info)
>  	return -EINVAL;
>  
>  	return gsm->ops->refresh_info(gsm, gsb);
> -- 
> 2.54.0

Re: [PATCH] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

Posted by Gautam Menghani 2 weeks, 5 days ago

On Tue, Sep 01, 2026 at 03:26:56PM +0200, nhuquynh@tutamail.com wrote:
> From 80fd05e6d156d5a90d4908f2498bf6cc7acbdefd Mon Sep 17 00:00:00 2001
> From: Bui Nguyen Nhu Quynh <nhuquynh@tutamail.com>
> Date: Tue, 1 Sep 2026 19:39:49 +0700
> Subject: [PATCH] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info
> 

This should not be in the patch description.

> The kvmppc_gsm_refresh_info() function incorrectly checks for the
> presence of the fill_info callback instead of refresh_info.
> 
> This can lead to:
> - NULL pointer dereference if refresh_info is NULL but fill_info is present
> - EINVAL return if refresh_info is present but fill_info is NULL
> 
> Fix this by checking the correct callback.
> 
> Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
> Signed-off-by: Bui Nguyen Nhu Quynh <nhuquynh@tutamail.com>
> ---
> arch/powerpc/kvm/guest-state-buffer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
> index 42843eca6727..aeb586ba4523 100644
> --- a/arch/powerpc/kvm/guest-state-buffer.c
> +++ b/arch/powerpc/kvm/guest-state-buffer.c
> @@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
> int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
>     struct kvmppc_gs_buff *gsb)
> {
> -	if (!gsm->ops->fill_info)
> +	if (!gsm->ops->refresh_info)
> return -EINVAL;
>  
> return gsm->ops->refresh_info(gsm, gsb);
> -- 
> 2.54.0


This patch does not apply

# git apply 20260901_nhuquynh_kvm_ppc_fix_callback_check_in_kvmppc_gsm_refresh_info.mbx --check --verbose
error: corrupt patch at 20260901_nhuquynh_kvm_ppc_fix_callback_check_in_kvmppc_gsm_refresh_info.mbx:30


The change itself is fine, but please fix the above issues and send a
v2. Refer the documentation in case something is not clear -
https://www.kernel.org/doc/html/latest/process/submitting-patches.html

Thanks,
Gautam