arch/x86/coco/sev/core.c:2838:12-13: WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line 2837) (fwd)

arch/x86/coco/sev/core.c:2838:12-13: WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line 2837) (fwd)

[Julia Lawall]

---------- Forwarded message ----------
Date: Sat, 20 Dec 2025 22:23:02 +0800
From: kernel test robot <lkp@intel.com>
To: oe-kbuild@lists.linux.dev
Cc: lkp@intel.com, Julia Lawall <julia.lawall@inria.fr>
Subject: arch/x86/coco/sev/core.c:2838:12-13: WARNING opportunity for
    kfree_sensitive/kvfree_sensitive (memset at line 2837)

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
CC: linux-kernel@vger.kernel.org
TO: Nikunj A Dadhania <nikunj@amd.com>
CC: "Borislav Petkov (AMD)" <bp@alien8.de>
CC: Tom Lendacky <thomas.lendacky@amd.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   dd9b004b7ff3289fb7bae35130c0a5c0537266af
commit: c5529418d05079384af4dbbb6f6156344c2ffce2 x86/sev: Carve out and export SNP guest messaging init routines
date:   12 months ago
:::::: branch date: 2 days ago
:::::: commit date: 12 months ago
config: x86_64-randconfig-104-20251217 (https://download.01.org/0day-ci/archive/20251220/202512202235.WHPQkLZu-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Julia Lawall <julia.lawall@inria.fr>
| Closes: https://lore.kernel.org/r/202512202235.WHPQkLZu-lkp@intel.com/

cocci warnings: (new ones prefixed by >>)
>> arch/x86/coco/sev/core.c:2838:12-13: WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line 2837)

vim +2838 arch/x86/coco/sev/core.c

c5529418d05079 Nikunj A Dadhania 2025-01-06  2825
c5529418d05079 Nikunj A Dadhania 2025-01-06  2826  void snp_msg_free(struct snp_msg_desc *mdesc)
c5529418d05079 Nikunj A Dadhania 2025-01-06  2827  {
c5529418d05079 Nikunj A Dadhania 2025-01-06  2828  	if (!mdesc)
c5529418d05079 Nikunj A Dadhania 2025-01-06  2829  		return;
c5529418d05079 Nikunj A Dadhania 2025-01-06  2830
c5529418d05079 Nikunj A Dadhania 2025-01-06  2831  	kfree(mdesc->ctx);
c5529418d05079 Nikunj A Dadhania 2025-01-06  2832  	free_shared_pages(mdesc->response, sizeof(struct snp_guest_msg));
c5529418d05079 Nikunj A Dadhania 2025-01-06  2833  	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
c5529418d05079 Nikunj A Dadhania 2025-01-06  2834  	free_shared_pages(mdesc->certs_data, SEV_FW_BLOB_MAX_SIZE);
c5529418d05079 Nikunj A Dadhania 2025-01-06  2835  	iounmap((__force void __iomem *)mdesc->secrets);
c5529418d05079 Nikunj A Dadhania 2025-01-06  2836
c5529418d05079 Nikunj A Dadhania 2025-01-06 @2837  	memset(mdesc, 0, sizeof(*mdesc));
c5529418d05079 Nikunj A Dadhania 2025-01-06 @2838  	kfree(mdesc);

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH] x86/sev: Use kfree_sensitive() when freeing a SNP message descriptor

[Borislav Petkov]

On Sat, Dec 20, 2025 at 03:25:46PM +0100, Julia Lawall wrote:
> cocci warnings: (new ones prefixed by >>)
> >> arch/x86/coco/sev/core.c:2838:12-13: WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line 2837)

From: "Borislav Petkov (AMD)" <bp@alien8.de>
Date: Mon, 12 Jan 2026 12:37:49 +0100

Use the proper helper instead of an open-coded variant.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202512202235.WHPQkLZu-lkp@intel.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
---
 arch/x86/coco/sev/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 379e0c09c7f3..38dad3f5f491 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -1632,8 +1632,7 @@ void snp_msg_free(struct snp_msg_desc *mdesc)
 	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
 	iounmap((__force void __iomem *)mdesc->secrets);
 
-	memset(mdesc, 0, sizeof(*mdesc));
-	kfree(mdesc);
+	kfree_sensitive(mdesc);
 }
 EXPORT_SYMBOL_GPL(snp_msg_free);
 
-- 
2.51.0



-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

Re: [PATCH] x86/sev: Use kfree_sensitive() when freeing a SNP message descriptor

[Tom Lendacky]

On 1/12/26 05:41, Borislav Petkov wrote:
> On Sat, Dec 20, 2025 at 03:25:46PM +0100, Julia Lawall wrote:
>> cocci warnings: (new ones prefixed by >>)
>>>> arch/x86/coco/sev/core.c:2838:12-13: WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line 2837)
> 
> From: "Borislav Petkov (AMD)" <bp@alien8.de>
> Date: Mon, 12 Jan 2026 12:37:49 +0100
> 
> Use the proper helper instead of an open-coded variant.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Julia Lawall <julia.lawall@inria.fr>
> Closes: https://lore.kernel.org/r/202512202235.WHPQkLZu-lkp@intel.com
> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>  arch/x86/coco/sev/core.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
> index 379e0c09c7f3..38dad3f5f491 100644
> --- a/arch/x86/coco/sev/core.c
> +++ b/arch/x86/coco/sev/core.c
> @@ -1632,8 +1632,7 @@ void snp_msg_free(struct snp_msg_desc *mdesc)
>  	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
>  	iounmap((__force void __iomem *)mdesc->secrets);
>  
> -	memset(mdesc, 0, sizeof(*mdesc));
> -	kfree(mdesc);
> +	kfree_sensitive(mdesc);
>  }
>  EXPORT_SYMBOL_GPL(snp_msg_free);
>  

[tip: x86/sev] x86/sev: Use kfree_sensitive() when freeing a SNP message descriptor

[tip-bot2 for Borislav Petkov (AMD)]

The following commit has been merged into the x86/sev branch of tip:

Commit-ID:     af05e558988ed004a20fc4de7d0f80cfbba663f0
Gitweb:        https://git.kernel.org/tip/af05e558988ed004a20fc4de7d0f80cfbba663f0
Author:        Borislav Petkov (AMD) <bp@alien8.de>
AuthorDate:    Mon, 12 Jan 2026 12:37:49 +01:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Tue, 20 Jan 2026 11:23:28 +01:00

x86/sev: Use kfree_sensitive() when freeing a SNP message descriptor

Use the proper helper instead of an open-coded variant.

Closes: https://lore.kernel.org/r/202512202235.WHPQkLZu-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260112114147.GBaWTd-8HSy_Xp4S3X@fat_crate.local
---
 arch/x86/coco/sev/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index a059e00..1b86f48 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -1632,8 +1632,7 @@ void snp_msg_free(struct snp_msg_desc *mdesc)
 	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
 	iounmap((__force void __iomem *)mdesc->secrets);
 
-	memset(mdesc, 0, sizeof(*mdesc));
-	kfree(mdesc);
+	kfree_sensitive(mdesc);
 }
 EXPORT_SYMBOL_GPL(snp_msg_free);