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  3. [PATCH v3 00/10] tpm: Decouple Trenchboot dependencies
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[PATCH v3 07/10] tpm-buf: check for corruption in tpm_buf_append_handle()

Jarkko Sakkinen posted 10 patches 4 months, 1 week ago
There is a newer version of this series
[PATCH v3 07/10] tpm-buf: check for corruption in tpm_buf_append_handle()
Posted by Jarkko Sakkinen 4 months, 1 week ago 
From: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>

Unify TPM_BUF_BOUNDARY_ERROR and TPM_BUF_OVERFLOW into TPM_BUF_INVALID
flag because semantically they are identical.

Test and set TPM_BUF_INVALID in tpm_buf_append_handle() following the
pattern from other functions in tpm-buf.c.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
---
v3:
- No changes.
v2:
- A new patch.
---
 drivers/char/tpm/tpm-buf.c                | 14 ++++++++------
 include/linux/tpm.h                       |  8 +++-----
 security/keys/trusted-keys/trusted_tpm2.c |  6 +++---
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
index dc882fc9fa9e..69ee77400539 100644
--- a/drivers/char/tpm/tpm-buf.c
+++ b/drivers/char/tpm/tpm-buf.c
@@ -104,13 +104,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_length);
  */
 void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length)
 {
-	/* Return silently if overflow has already happened. */
-	if (buf->flags & TPM_BUF_OVERFLOW)
+	if (buf->flags & TPM_BUF_INVALID)
 		return;
 
 	if ((buf->length + new_length) > PAGE_SIZE) {
 		WARN(1, "tpm_buf: write overflow\n");
-		buf->flags |= TPM_BUF_OVERFLOW;
+		buf->flags |= TPM_BUF_INVALID;
 		return;
 	}
 
@@ -157,8 +156,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_append_u32);
  */
 void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle)
 {
+	if (buf->flags & TPM_BUF_INVALID)
+		return;
+
 	if (buf->flags & TPM_BUF_TPM2B) {
 		dev_err(&chip->dev, "Invalid buffer type (TPM2B)\n");
+		buf->flags |= TPM_BUF_INVALID;
 		return;
 	}
 
@@ -177,14 +180,13 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
 {
 	off_t next_offset;
 
-	/* Return silently if overflow has already happened. */
-	if (buf->flags & TPM_BUF_BOUNDARY_ERROR)
+	if (buf->flags & TPM_BUF_INVALID)
 		return;
 
 	next_offset = *offset + count;
 	if (next_offset > buf->length) {
 		WARN(1, "tpm_buf: read out of boundary\n");
-		buf->flags |= TPM_BUF_BOUNDARY_ERROR;
+		buf->flags |= TPM_BUF_INVALID;
 		return;
 	}
 
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index e72e7657faa2..5283f32781c4 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -366,12 +366,10 @@ struct tpm_header {
 } __packed;
 
 enum tpm_buf_flags {
-	/* the capacity exceeded: */
-	TPM_BUF_OVERFLOW	= BIT(0),
 	/* TPM2B format: */
-	TPM_BUF_TPM2B		= BIT(1),
-	/* read out of boundary: */
-	TPM_BUF_BOUNDARY_ERROR	= BIT(2),
+	TPM_BUF_TPM2B		= BIT(0),
+	/* The buffer is in invalid and unusable state: */
+	TPM_BUF_INVALID		= BIT(1),
 };
 
 /*
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 8e3b283a59b2..119d5152c0db 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -295,7 +295,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 	/* creation PCR */
 	tpm_buf_append_u32(&buf, 0);
 
-	if (buf.flags & TPM_BUF_OVERFLOW) {
+	if (buf.flags & TPM_BUF_INVALID) {
 		rc = -E2BIG;
 		tpm2_end_auth_session(chip);
 		goto out;
@@ -308,7 +308,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 		goto out;
 
 	blob_len = tpm_buf_read_u32(&buf, &offset);
-	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_BOUNDARY_ERROR) {
+	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_INVALID) {
 		rc = -E2BIG;
 		goto out;
 	}
@@ -414,7 +414,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
 
 	tpm_buf_append(&buf, blob, blob_len);
 
-	if (buf.flags & TPM_BUF_OVERFLOW) {
+	if (buf.flags & TPM_BUF_INVALID) {
 		rc = -E2BIG;
 		tpm2_end_auth_session(chip);
 		goto out;
-- 
2.39.5
Re: [PATCH v3 07/10] tpm-buf: check for corruption in tpm_buf_append_handle()
Posted by Jonathan McDowell 4 months, 1 week ago 
On Mon, Sep 29, 2025 at 10:48:29PM +0300, Jarkko Sakkinen wrote:
> From: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
> 
> Unify TPM_BUF_BOUNDARY_ERROR and TPM_BUF_OVERFLOW into TPM_BUF_INVALID
> flag because semantically they are identical.
> 
> Test and set TPM_BUF_INVALID in tpm_buf_append_handle() following the
> pattern from other functions in tpm-buf.c.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>

Reviewed-by: Jonathan McDowell <noodles@meta.com>

> ---
> v3:
> - No changes.
> v2:
> - A new patch.
> ---
>  drivers/char/tpm/tpm-buf.c                | 14 ++++++++------
>  include/linux/tpm.h                       |  8 +++-----
>  security/keys/trusted-keys/trusted_tpm2.c |  6 +++---
>  3 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> index dc882fc9fa9e..69ee77400539 100644
> --- a/drivers/char/tpm/tpm-buf.c
> +++ b/drivers/char/tpm/tpm-buf.c
> @@ -104,13 +104,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_length);
>   */
>  void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length)
>  {
> -	/* Return silently if overflow has already happened. */
> -	if (buf->flags & TPM_BUF_OVERFLOW)
> +	if (buf->flags & TPM_BUF_INVALID)
>  		return;
>  
>  	if ((buf->length + new_length) > PAGE_SIZE) {
>  		WARN(1, "tpm_buf: write overflow\n");
> -		buf->flags |= TPM_BUF_OVERFLOW;
> +		buf->flags |= TPM_BUF_INVALID;
>  		return;
>  	}
>  
> @@ -157,8 +156,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_append_u32);
>   */
>  void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle)
>  {
> +	if (buf->flags & TPM_BUF_INVALID)
> +		return;
> +
>  	if (buf->flags & TPM_BUF_TPM2B) {
>  		dev_err(&chip->dev, "Invalid buffer type (TPM2B)\n");
> +		buf->flags |= TPM_BUF_INVALID;
>  		return;
>  	}
>  
> @@ -177,14 +180,13 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
>  {
>  	off_t next_offset;
>  
> -	/* Return silently if overflow has already happened. */
> -	if (buf->flags & TPM_BUF_BOUNDARY_ERROR)
> +	if (buf->flags & TPM_BUF_INVALID)
>  		return;
>  
>  	next_offset = *offset + count;
>  	if (next_offset > buf->length) {
>  		WARN(1, "tpm_buf: read out of boundary\n");
> -		buf->flags |= TPM_BUF_BOUNDARY_ERROR;
> +		buf->flags |= TPM_BUF_INVALID;
>  		return;
>  	}
>  
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index e72e7657faa2..5283f32781c4 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -366,12 +366,10 @@ struct tpm_header {
>  } __packed;
>  
>  enum tpm_buf_flags {
> -	/* the capacity exceeded: */
> -	TPM_BUF_OVERFLOW	= BIT(0),
>  	/* TPM2B format: */
> -	TPM_BUF_TPM2B		= BIT(1),
> -	/* read out of boundary: */
> -	TPM_BUF_BOUNDARY_ERROR	= BIT(2),
> +	TPM_BUF_TPM2B		= BIT(0),
> +	/* The buffer is in invalid and unusable state: */
> +	TPM_BUF_INVALID		= BIT(1),
>  };
>  
>  /*
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index 8e3b283a59b2..119d5152c0db 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -295,7 +295,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
>  	/* creation PCR */
>  	tpm_buf_append_u32(&buf, 0);
>  
> -	if (buf.flags & TPM_BUF_OVERFLOW) {
> +	if (buf.flags & TPM_BUF_INVALID) {
>  		rc = -E2BIG;
>  		tpm2_end_auth_session(chip);
>  		goto out;
> @@ -308,7 +308,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
>  		goto out;
>  
>  	blob_len = tpm_buf_read_u32(&buf, &offset);
> -	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_BOUNDARY_ERROR) {
> +	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_INVALID) {
>  		rc = -E2BIG;
>  		goto out;
>  	}
> @@ -414,7 +414,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
>  
>  	tpm_buf_append(&buf, blob, blob_len);
>  
> -	if (buf.flags & TPM_BUF_OVERFLOW) {
> +	if (buf.flags & TPM_BUF_INVALID) {
>  		rc = -E2BIG;
>  		tpm2_end_auth_session(chip);
>  		goto out;
> -- 
> 2.39.5
> 
> 

J.

-- 
Web [       Reality is for people with no grasp of fantasy.        ]
site: https:// [                                          ]      Made by
www.earth.li/~noodles/  [                      ]         HuggieTag 0.0.24
Re: [PATCH v3 07/10] tpm-buf: check for corruption in tpm_buf_append_handle()
Posted by Jarkko Sakkinen 4 months, 1 week ago 
On Tue, Sep 30, 2025 at 12:13:11PM +0100, Jonathan McDowell wrote:
> On Mon, Sep 29, 2025 at 10:48:29PM +0300, Jarkko Sakkinen wrote:
> > From: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
> > 
> > Unify TPM_BUF_BOUNDARY_ERROR and TPM_BUF_OVERFLOW into TPM_BUF_INVALID
> > flag because semantically they are identical.
> > 
> > Test and set TPM_BUF_INVALID in tpm_buf_append_handle() following the
> > pattern from other functions in tpm-buf.c.
> > 
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
> 
> Reviewed-by: Jonathan McDowell <noodles@meta.com>

Thanks.

> 
> > ---
> > v3:
> > - No changes.
> > v2:
> > - A new patch.
> > ---
> >  drivers/char/tpm/tpm-buf.c                | 14 ++++++++------
> >  include/linux/tpm.h                       |  8 +++-----
> >  security/keys/trusted-keys/trusted_tpm2.c |  6 +++---
> >  3 files changed, 14 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> > index dc882fc9fa9e..69ee77400539 100644
> > --- a/drivers/char/tpm/tpm-buf.c
> > +++ b/drivers/char/tpm/tpm-buf.c
> > @@ -104,13 +104,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_length);
> >   */
> >  void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length)
> >  {
> > -	/* Return silently if overflow has already happened. */
> > -	if (buf->flags & TPM_BUF_OVERFLOW)
> > +	if (buf->flags & TPM_BUF_INVALID)
> >  		return;
> >  
> >  	if ((buf->length + new_length) > PAGE_SIZE) {
> >  		WARN(1, "tpm_buf: write overflow\n");
> > -		buf->flags |= TPM_BUF_OVERFLOW;
> > +		buf->flags |= TPM_BUF_INVALID;
> >  		return;
> >  	}
> >  
> > @@ -157,8 +156,12 @@ EXPORT_SYMBOL_GPL(tpm_buf_append_u32);
> >   */
> >  void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle)
> >  {
> > +	if (buf->flags & TPM_BUF_INVALID)
> > +		return;
> > +
> >  	if (buf->flags & TPM_BUF_TPM2B) {
> >  		dev_err(&chip->dev, "Invalid buffer type (TPM2B)\n");
> > +		buf->flags |= TPM_BUF_INVALID;
> >  		return;
> >  	}
> >  
> > @@ -177,14 +180,13 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
> >  {
> >  	off_t next_offset;
> >  
> > -	/* Return silently if overflow has already happened. */
> > -	if (buf->flags & TPM_BUF_BOUNDARY_ERROR)
> > +	if (buf->flags & TPM_BUF_INVALID)
> >  		return;
> >  
> >  	next_offset = *offset + count;
> >  	if (next_offset > buf->length) {
> >  		WARN(1, "tpm_buf: read out of boundary\n");
> > -		buf->flags |= TPM_BUF_BOUNDARY_ERROR;
> > +		buf->flags |= TPM_BUF_INVALID;
> >  		return;
> >  	}
> >  
> > diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> > index e72e7657faa2..5283f32781c4 100644
> > --- a/include/linux/tpm.h
> > +++ b/include/linux/tpm.h
> > @@ -366,12 +366,10 @@ struct tpm_header {
> >  } __packed;
> >  
> >  enum tpm_buf_flags {
> > -	/* the capacity exceeded: */
> > -	TPM_BUF_OVERFLOW	= BIT(0),
> >  	/* TPM2B format: */
> > -	TPM_BUF_TPM2B		= BIT(1),
> > -	/* read out of boundary: */
> > -	TPM_BUF_BOUNDARY_ERROR	= BIT(2),
> > +	TPM_BUF_TPM2B		= BIT(0),
> > +	/* The buffer is in invalid and unusable state: */
> > +	TPM_BUF_INVALID		= BIT(1),
> >  };
> >  
> >  /*
> > diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> > index 8e3b283a59b2..119d5152c0db 100644
> > --- a/security/keys/trusted-keys/trusted_tpm2.c
> > +++ b/security/keys/trusted-keys/trusted_tpm2.c
> > @@ -295,7 +295,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> >  	/* creation PCR */
> >  	tpm_buf_append_u32(&buf, 0);
> >  
> > -	if (buf.flags & TPM_BUF_OVERFLOW) {
> > +	if (buf.flags & TPM_BUF_INVALID) {
> >  		rc = -E2BIG;
> >  		tpm2_end_auth_session(chip);
> >  		goto out;
> > @@ -308,7 +308,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> >  		goto out;
> >  
> >  	blob_len = tpm_buf_read_u32(&buf, &offset);
> > -	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_BOUNDARY_ERROR) {
> > +	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_INVALID) {
> >  		rc = -E2BIG;
> >  		goto out;
> >  	}
> > @@ -414,7 +414,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> >  
> >  	tpm_buf_append(&buf, blob, blob_len);
> >  
> > -	if (buf.flags & TPM_BUF_OVERFLOW) {
> > +	if (buf.flags & TPM_BUF_INVALID) {
> >  		rc = -E2BIG;
> >  		tpm2_end_auth_session(chip);
> >  		goto out;
> > -- 
> > 2.39.5
> > 
> > 
> 
> J.
> 
> -- 
> Web [       Reality is for people with no grasp of fantasy.        ]
> site: https:// [                                          ]      Made by
> www.earth.li/~noodles/  [                      ]         HuggieTag 0.0.24

BR, Jarkko

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