[PATCH] ima: silence measurement list hexdump during kexec

[PATCH] ima: silence measurement list hexdump during kexec

[Bruno Meneguele]

The measurement list is dumped during a soft reset (kexec) through the call
to "print_hex_dump(KERN_DEBUG, ...)", which ignores the DEBUG build flag.
Instead, use "print_hex_dump_debug(...)", honoring the build flag.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
---
 security/integrity/ima/ima_kexec.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index f799cc278a9a..13753136f03f 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -61,9 +61,9 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
 	}
 	memcpy(file.buf, &khdr, sizeof(khdr));
 
-	print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE,
-			16, 1, file.buf,
-			file.count < 100 ? file.count : 100, true);
+	print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1,
+			     file.buf, file.count < 100 ? file.count : 100,
+			     true);
 
 	*buffer_size = file.count;
 	*buffer = file.buf;
-- 
2.33.1

Re: [PATCH] ima: silence measurement list hexdump during kexec

[Mimi Zohar]

Hi Bruno,

On Wed, 2021-12-22 at 16:16 -0300, Bruno Meneguele wrote:
> The measurement list is dumped during a soft reset (kexec) through the call
> to "print_hex_dump(KERN_DEBUG, ...)", which ignores the DEBUG build flag.
> Instead, use "print_hex_dump_debug(...)", honoring the build flag.
> 
> Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>

The patch description needs to at least explain why using
print_hex_dump() isn't sufficent.   Look at how print_hex_dump() is
defined.  Based on whether CONFIG_DYNAMIC_DEBUG is enabled, different
functions are used.

Mimi

> ---
>  security/integrity/ima/ima_kexec.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
> index f799cc278a9a..13753136f03f 100644
> --- a/security/integrity/ima/ima_kexec.c
> +++ b/security/integrity/ima/ima_kexec.c
> @@ -61,9 +61,9 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
>  	}
>  	memcpy(file.buf, &khdr, sizeof(khdr));
>  
> -	print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE,
> -			16, 1, file.buf,
> -			file.count < 100 ? file.count : 100, true);
> +	print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1,
> +			     file.buf, file.count < 100 ? file.count : 100,
> +			     true);
>  
>  	*buffer_size = file.count;
>  	*buffer = file.buf;

Re: [PATCH] ima: silence measurement list hexdump during kexec

[Bruno Meneguele]

[-- Attachment #1: Type: text/plain, Size: 1666 bytes --]

On Wed, Dec 22, 2021 at 05:13:56PM -0500, Mimi Zohar wrote:
> Hi Bruno,
> 
> On Wed, 2021-12-22 at 16:16 -0300, Bruno Meneguele wrote:
> > The measurement list is dumped during a soft reset (kexec) through the call
> > to "print_hex_dump(KERN_DEBUG, ...)", which ignores the DEBUG build flag.
> > Instead, use "print_hex_dump_debug(...)", honoring the build flag.
> > 
> > Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
> 
> The patch description needs to at least explain why using
> print_hex_dump() isn't sufficent.   Look at how print_hex_dump() is
> defined.  Based on whether CONFIG_DYNAMIC_DEBUG is enabled, different
> functions are used.

Sending the v2 in a sec :)

Thanks Mimi

> 
> Mimi
> 
> > ---
> >  security/integrity/ima/ima_kexec.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
> > index f799cc278a9a..13753136f03f 100644
> > --- a/security/integrity/ima/ima_kexec.c
> > +++ b/security/integrity/ima/ima_kexec.c
> > @@ -61,9 +61,9 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
> >  	}
> >  	memcpy(file.buf, &khdr, sizeof(khdr));
> >  
> > -	print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE,
> > -			16, 1, file.buf,
> > -			file.count < 100 ? file.count : 100, true);
> > +	print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1,
> > +			     file.buf, file.count < 100 ? file.count : 100,
> > +			     true);
> >  
> >  	*buffer_size = file.count;
> >  	*buffer = file.buf;
> 
> 

-- 
bmeneg 
PGP Key: http://bmeneg.com/pubkey.txt

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