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* [dm-devel] [PATCH] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by
@ 2023-08-17 23:59 ` Kees Cook
  0 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2023-08-17 23:59 UTC (permalink / raw)
  To: linux-hardening
  Cc: linux-security-module, Kees Cook, Nick Desaulniers, llvm,
	Mike Snitzer, James Morris, linux-kernel, Nathan Chancellor,
	dm-devel, Tom Rix, Serge E. Hallyn, Alasdair Kergon, Paul Moore

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct dm_verity_loadpin_trusted_root_digest.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: dm-devel@redhat.com
Cc: Paul Moore <paul@paul-moore.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/dm-verity-loadpin.h | 2 +-
 security/loadpin/loadpin.c        | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/linux/dm-verity-loadpin.h b/include/linux/dm-verity-loadpin.h
index 552b817ab102..3ac6dbaeaa37 100644
--- a/include/linux/dm-verity-loadpin.h
+++ b/include/linux/dm-verity-loadpin.h
@@ -12,7 +12,7 @@ extern struct list_head dm_verity_loadpin_trusted_root_digests;
 struct dm_verity_loadpin_trusted_root_digest {
 	struct list_head node;
 	unsigned int len;
-	u8 data[];
+	u8 data[] __counted_by(len);
 };
 
 #if IS_ENABLED(CONFIG_SECURITY_LOADPIN_VERITY)
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index ebae964f7cc9..a9d40456a064 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -336,6 +336,7 @@ static int read_trusted_verity_root_digests(unsigned int fd)
 			rc = -ENOMEM;
 			goto err;
 		}
+		trd->len = len;
 
 		if (hex2bin(trd->data, d, len)) {
 			kfree(trd);
@@ -343,8 +344,6 @@ static int read_trusted_verity_root_digests(unsigned int fd)
 			goto err;
 		}
 
-		trd->len = len;
-
 		list_add_tail(&trd->node, &dm_verity_loadpin_trusted_root_digests);
 	}
 
-- 
2.34.1

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by
@ 2023-08-17 23:59 ` Kees Cook
  0 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2023-08-17 23:59 UTC (permalink / raw)
  To: linux-hardening
  Cc: Kees Cook, Alasdair Kergon, Mike Snitzer, dm-devel, Paul Moore,
	James Morris, Serge E. Hallyn, linux-security-module,
	Nathan Chancellor, Nick Desaulniers, Tom Rix, linux-kernel, llvm

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct dm_verity_loadpin_trusted_root_digest.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: dm-devel@redhat.com
Cc: Paul Moore <paul@paul-moore.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/dm-verity-loadpin.h | 2 +-
 security/loadpin/loadpin.c        | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/linux/dm-verity-loadpin.h b/include/linux/dm-verity-loadpin.h
index 552b817ab102..3ac6dbaeaa37 100644
--- a/include/linux/dm-verity-loadpin.h
+++ b/include/linux/dm-verity-loadpin.h
@@ -12,7 +12,7 @@ extern struct list_head dm_verity_loadpin_trusted_root_digests;
 struct dm_verity_loadpin_trusted_root_digest {
 	struct list_head node;
 	unsigned int len;
-	u8 data[];
+	u8 data[] __counted_by(len);
 };
 
 #if IS_ENABLED(CONFIG_SECURITY_LOADPIN_VERITY)
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index ebae964f7cc9..a9d40456a064 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -336,6 +336,7 @@ static int read_trusted_verity_root_digests(unsigned int fd)
 			rc = -ENOMEM;
 			goto err;
 		}
+		trd->len = len;
 
 		if (hex2bin(trd->data, d, len)) {
 			kfree(trd);
@@ -343,8 +344,6 @@ static int read_trusted_verity_root_digests(unsigned int fd)
 			goto err;
 		}
 
-		trd->len = len;
-
 		list_add_tail(&trd->node, &dm_verity_loadpin_trusted_root_digests);
 	}
 
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [dm-devel] [PATCH] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by
  2023-08-17 23:59 ` Kees Cook
@ 2023-08-25 23:08   ` Kees Cook
  -1 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2023-08-25 23:08 UTC (permalink / raw)
  To: linux-hardening, Kees Cook
  Cc: linux-security-module, Paul Moore, Nick Desaulniers, llvm,
	Mike Snitzer, James Morris, linux-kernel, Nathan Chancellor,
	dm-devel, Tom Rix, Alasdair Kergon, Serge E. Hallyn

On Thu, 17 Aug 2023 16:59:56 -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct dm_verity_loadpin_trusted_root_digest.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
> 
> [...]

Applied to for-next/hardening, thanks!

[1/1] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by
      https://git.kernel.org/kees/c/5f536ac6a5a7

Take care,

-- 
Kees Cook

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by
@ 2023-08-25 23:08   ` Kees Cook
  0 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2023-08-25 23:08 UTC (permalink / raw)
  To: linux-hardening, Kees Cook
  Cc: Alasdair Kergon, Mike Snitzer, dm-devel, Paul Moore, James Morris,
	Serge E. Hallyn, linux-security-module, Nathan Chancellor,
	Nick Desaulniers, Tom Rix, linux-kernel, llvm

On Thu, 17 Aug 2023 16:59:56 -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct dm_verity_loadpin_trusted_root_digest.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
> 
> [...]

Applied to for-next/hardening, thanks!

[1/1] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by
      https://git.kernel.org/kees/c/5f536ac6a5a7

Take care,

-- 
Kees Cook


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-08-25 23:08 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2023-08-17 23:59 [dm-devel] [PATCH] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by Kees Cook
2023-08-17 23:59 ` Kees Cook
2023-08-25 23:08 ` [dm-devel] " Kees Cook
2023-08-25 23:08   ` Kees Cook

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