[PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Saul Wold]

This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
defined in the security_flags.inc and override the empty default.

Signed-off-by: Saul Wold <sgw@linux.intel.com>
---
 meta/conf/bitbake.conf | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 62a3936..72e1a78 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -493,7 +493,8 @@ export TARGET_CPPFLAGS = ""
 
 export BUILD_CFLAGS = "${BUILD_CPPFLAGS} ${BUILD_OPTIMIZATION}"
 BUILDSDK_CFLAGS = "${BUILDSDK_CPPFLAGS} ${BUILD_OPTIMIZATION}"
-export CFLAGS = "${TARGET_CFLAGS}"
+SECURITY_CFLAGS ?= ""
+export CFLAGS = "${TARGET_CFLAGS} ${SECURITY_CFLAGS}"
 export TARGET_CFLAGS = "${TARGET_CPPFLAGS} ${SELECTED_OPTIMIZATION}"
 
 export BUILD_CXXFLAGS = "${BUILD_CFLAGS} -fpermissive"
@@ -523,7 +524,8 @@ LINKER_HASH_STYLE_mips64 = "sysv"
 LINKER_HASH_STYLE_mips64el = "sysv"
 TARGET_LINK_HASH_STYLE ?= "${@['-Wl,--hash-style=gnu',''][d.getVar('LINKER_HASH_STYLE', True) != 'gnu']}"
 
-export LDFLAGS = "${TARGET_LDFLAGS}"
+SECURITY_LDFLAGS ?= ""
+export LDFLAGS = "${TARGET_LDFLAGS} ${SECURITY_LDFLAGS}"
 export TARGET_LDFLAGS = "-Wl,-O1 ${TARGET_LINK_HASH_STYLE}"
 #export TARGET_LDFLAGS = "-L${STAGING_DIR_TARGET}${libdir} \
 #                         -Wl,-rpath-link,${STAGING_DIR_TARGET}${libdir} \
-- 
1.8.1.4

[PATCH 2/2 v2] security_flags: Add the compiler and linker flags that enhance security

[Saul Wold]

These flags add addition checks at compile, link and runtime to prevent
stack smashing, checking for buffer overflows, and link at program start
to prevent call spoofing later.

This needs to be explicitly enabled by adding the following line to your
local.conf:

require conf/distro/include/security_flags.inc

[YOCTO #3868]

Signed-off-by: Saul Wold <sgw@linux.intel.com>
---
 meta/conf/distro/include/security_flags.inc | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 meta/conf/distro/include/security_flags.inc

diff --git a/meta/conf/distro/include/security_flags.inc b/meta/conf/distro/include/security_flags.inc
new file mode 100644
index 0000000..1c1f980
--- /dev/null
+++ b/meta/conf/distro/include/security_flags.inc
@@ -0,0 +1,23 @@
+SECURITY_CFLAGS = "-fstack-protector-all -pie -fpie -D_FORTIFY_SOURCE=2"
+SECURITY_LDFLAGS = "-Wl,-z,relro,-z,now"
+
+# Curl seems to check for FORTIFY_SOURCE in CFLAGS, but even assigned
+# to CPPFLAGS it gets picked into CFLAGS in bitbake.
+#TARGET_CPPFLAGS_pn-curl += "-D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-curl = "-fstack-protector-all -pie -fpie"
+SECURITY_CFLAGS_pn-ppp = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-eglibc = ""
+SECURITY_CFLAGS_pn-eglibc-initial = ""
+SECURITY_CFLAGS_pn-zlib = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-gcc-runtime = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-libgcc = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-tcl = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-libcap = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-python-smartpm = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-python-imaging = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-python-pycurl = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-kexec-tools = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+
+# These 2 have text relco errors with the pie options enabled
+SECURITY_CFLAGS_pn-pulseaudio = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
+SECURITY_CFLAGS_pn-ltp = "-fstack-protector-all -D_FORTIFY_SOURCE=2"
-- 
1.8.1.4

Re: [PATCH 2/2 v2] security_flags: Add the compiler and linker flags that enhance security

[Khem Raj]

On Jun 28, 2013, at 12:23 PM, Saul Wold <sgw@linux.intel.com> wrote:

> +# These 2 have text relco errors with the pie options enabled

typo

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Mark Hatle]

On 6/28/13 2:23 PM, Saul Wold wrote:
> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
> defined in the security_flags.inc and override the empty default.
>
> Signed-off-by: Saul Wold <sgw@linux.intel.com>
> ---
>   meta/conf/bitbake.conf | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
> index 62a3936..72e1a78 100644
> --- a/meta/conf/bitbake.conf
> +++ b/meta/conf/bitbake.conf
> @@ -493,7 +493,8 @@ export TARGET_CPPFLAGS = ""
>
>   export BUILD_CFLAGS = "${BUILD_CPPFLAGS} ${BUILD_OPTIMIZATION}"
>   BUILDSDK_CFLAGS = "${BUILDSDK_CPPFLAGS} ${BUILD_OPTIMIZATION}"
> -export CFLAGS = "${TARGET_CFLAGS}"
> +SECURITY_CFLAGS ?= ""
> +export CFLAGS = "${TARGET_CFLAGS} ${SECURITY_CFLAGS}"
>   export TARGET_CFLAGS = "${TARGET_CPPFLAGS} ${SELECTED_OPTIMIZATION}"

I would prefer if the cflags came in via the TARGET_CFLAGS, similar to how the 
selected_optimization works.  In the past we've hacked around with CFLAGS itself 
and in the end it's always seem to have caused problems.  By modifing 
TARGET_CFLAGS instead, then the user can do (in a recipe):

CFLAGS = "-fmy-custom-flag ${TARGET_CFLAGS}"

>   export BUILD_CXXFLAGS = "${BUILD_CFLAGS} -fpermissive"
> @@ -523,7 +524,8 @@ LINKER_HASH_STYLE_mips64 = "sysv"
>   LINKER_HASH_STYLE_mips64el = "sysv"
>   TARGET_LINK_HASH_STYLE ?= "${@['-Wl,--hash-style=gnu',''][d.getVar('LINKER_HASH_STYLE', True) != 'gnu']}"
>
> -export LDFLAGS = "${TARGET_LDFLAGS}"
> +SECURITY_LDFLAGS ?= ""
> +export LDFLAGS = "${TARGET_LDFLAGS} ${SECURITY_LDFLAGS}"

Same comment here.

>   export TARGET_LDFLAGS = "-Wl,-O1 ${TARGET_LINK_HASH_STYLE}"
>   #export TARGET_LDFLAGS = "-L${STAGING_DIR_TARGET}${libdir} \
>   #                         -Wl,-rpath-link,${STAGING_DIR_TARGET}${libdir} \
>

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Khem Raj]

On Jun 28, 2013, at 12:28 PM, Mark Hatle <mark.hatle@windriver.com> wrote:

> On 6/28/13 2:23 PM, Saul Wold wrote:
>> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
>> defined in the security_flags.inc and override the empty default.
>> 
>> Signed-off-by: Saul Wold <sgw@linux.intel.com>
>> ---
>>  meta/conf/bitbake.conf | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>> 
>> diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
>> index 62a3936..72e1a78 100644
>> --- a/meta/conf/bitbake.conf
>> +++ b/meta/conf/bitbake.conf
>> @@ -493,7 +493,8 @@ export TARGET_CPPFLAGS = ""
>> 
>>  export BUILD_CFLAGS = "${BUILD_CPPFLAGS} ${BUILD_OPTIMIZATION}"
>>  BUILDSDK_CFLAGS = "${BUILDSDK_CPPFLAGS} ${BUILD_OPTIMIZATION}"
>> -export CFLAGS = "${TARGET_CFLAGS}"
>> +SECURITY_CFLAGS ?= ""
>> +export CFLAGS = "${TARGET_CFLAGS} ${SECURITY_CFLAGS}"
>>  export TARGET_CFLAGS = "${TARGET_CPPFLAGS} ${SELECTED_OPTIMIZATION}"
> 
> I would prefer if the cflags came in via the TARGET_CFLAGS, similar to how the selected_optimization works.  In the past we've hacked around with CFLAGS itself and in the end it's always seem to have caused problems.  By modifing TARGET_CFLAGS instead, then the user can do (in a recipe):
> 
> CFLAGS = "-fmy-custom-flag ${TARGET_CFLAGS}"

yes infact it should be added via TARGET_CFLAGS 

> 
>>  export BUILD_CXXFLAGS = "${BUILD_CFLAGS} -fpermissive"
>> @@ -523,7 +524,8 @@ LINKER_HASH_STYLE_mips64 = "sysv"
>>  LINKER_HASH_STYLE_mips64el = "sysv"
>>  TARGET_LINK_HASH_STYLE ?= "${@['-Wl,--hash-style=gnu',''][d.getVar('LINKER_HASH_STYLE', True) != 'gnu']}"
>> 
>> -export LDFLAGS = "${TARGET_LDFLAGS}"
>> +SECURITY_LDFLAGS ?= ""
>> +export LDFLAGS = "${TARGET_LDFLAGS} ${SECURITY_LDFLAGS}"
> 
> Same comment here.
> 
>>  export TARGET_LDFLAGS = "-Wl,-O1 ${TARGET_LINK_HASH_STYLE}"
>>  #export TARGET_LDFLAGS = "-L${STAGING_DIR_TARGET}${libdir} \
>>  #                         -Wl,-rpath-link,${STAGING_DIR_TARGET}${libdir} \
>> 
> 
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-core

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Phil Blundell]

On Fri, 2013-06-28 at 12:23 -0700, Saul Wold wrote:
> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
> defined in the security_flags.inc and override the empty default.

Why can't security_flags.inc just append to CFLAGS and LDFLAGS
respectively, or some other set of variables that already exists?

Creating new variables in bitbake.conf does have a cost in terms of
parse time and memory footprint for every recipe.  If the variables are
referenced in ${CFLAGS} etc then it also adds an extra substitution
whenever CFLAGS is expanded.  The cost of those things isn't enormous,
but it isn't zero either and adding them isn't something that we should
do capriciously.

p.

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Saul Wold]

On 06/28/2013 12:51 PM, Phil Blundell wrote:
> On Fri, 2013-06-28 at 12:23 -0700, Saul Wold wrote:
>> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
>> defined in the security_flags.inc and override the empty default.
>
> Why can't security_flags.inc just append to CFLAGS and LDFLAGS
> respectively, or some other set of variables that already exists?
>
So, if I remember correctly there was issues with this because there are 
a number of packages that have to modify specifically the security 
related flags (see the list in security_flags.inc), the ordering/timing 
of being able to due that correctly did not allow for setting it 
directly in CFLAGS or TARGET_CFLAGS.

> Creating new variables in bitbake.conf does have a cost in terms of
> parse time and memory footprint for every recipe.  If the variables are
> referenced in ${CFLAGS} etc then it also adds an extra substitution
> whenever CFLAGS is expanded.  The cost of those things isn't enormous,
> but it isn't zero either and adding them isn't something that we should
> do capriciously.
>
I understand, and RP and I talked about this, we needed a separate 
variable to ensure the correct substitution occurred for those that 
needed to disable or remove certain flags.

Sau!


> p.
>
>
>
>

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Richard Purdie]

On Fri, 2013-06-28 at 13:19 -0700, Saul Wold wrote:
> On 06/28/2013 12:51 PM, Phil Blundell wrote:
> > On Fri, 2013-06-28 at 12:23 -0700, Saul Wold wrote:
> >> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
> >> defined in the security_flags.inc and override the empty default.
> >
> > Why can't security_flags.inc just append to CFLAGS and LDFLAGS
> > respectively, or some other set of variables that already exists?
> >
> So, if I remember correctly there was issues with this because there are 
> a number of packages that have to modify specifically the security 
> related flags (see the list in security_flags.inc), the ordering/timing 
> of being able to due that correctly did not allow for setting it 
> directly in CFLAGS or TARGET_CFLAGS.
> 
> > Creating new variables in bitbake.conf does have a cost in terms of
> > parse time and memory footprint for every recipe.  If the variables are
> > referenced in ${CFLAGS} etc then it also adds an extra substitution
> > whenever CFLAGS is expanded.  The cost of those things isn't enormous,
> > but it isn't zero either and adding them isn't something that we should
> > do capriciously.
> >
> I understand, and RP and I talked about this, we needed a separate 
> variable to ensure the correct substitution occurred for those that 
> needed to disable or remove certain flags.

What RP said was that he'd prefer to see no bitbake.conf changes and to
do this all in the .inc. We should have a variable like the
SECURITY_FLAGS you have but this can also be appended in the .inc.

If we need to modify it on a per recipe basis we still then can so:

SECURITY_CFLAGS = "-fstack-protector-all -pie -fpie -D_FORTIFY_SOURCE=2"
TARGET_CFLAGS_append = " ${SECURITY_CFLAGS}"

SECURITY_LDFLAGS = "-Wl,-z,relro,-z,now"
TARGET_LDFLAGS_append = " ${SECURITY_LDFLAGS}"

all in the .inc. Or am I missing something?

Cheers,

Richard

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Phil Blundell]

On Fri, 2013-06-28 at 13:19 -0700, Saul Wold wrote:
> So, if I remember correctly there was issues with this because there are 
> a number of packages that have to modify specifically the security 
> related flags (see the list in security_flags.inc), the ordering/timing 
> of being able to due that correctly did not allow for setting it 
> directly in CFLAGS or TARGET_CFLAGS.

What exactly were the issues?  I can't think of any obvious reason why
it wouldn't work for security.inc to do:

SECURITY_CFLAGS = "-fstack-protector-all -pie -fpie -D_FORTIFY_SOURCE=2"
SECURITY_CFLAGS_pn-curl = "-fstack-protector-all -pie -fpie"
CFLAGS += "${SECURITY_CFLAGS}"

p.

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Saul Wold]

On 06/28/2013 02:07 PM, Phil Blundell wrote:
> On Fri, 2013-06-28 at 13:19 -0700, Saul Wold wrote:
>> So, if I remember correctly there was issues with this because there are
>> a number of packages that have to modify specifically the security
>> related flags (see the list in security_flags.inc), the ordering/timing
>> of being able to due that correctly did not allow for setting it
>> directly in CFLAGS or TARGET_CFLAGS.
>
> What exactly were the issues?  I can't think of any obvious reason why
> it wouldn't work for security.inc to do:
>
> SECURITY_CFLAGS = "-fstack-protector-all -pie -fpie -D_FORTIFY_SOURCE=2"
> SECURITY_CFLAGS_pn-curl = "-fstack-protector-all -pie -fpie"
> CFLAGS += "${SECURITY_CFLAGS}"
>
Seems either will work, this or TARGET_CFLAGS_append, I guess the 
problem I had in the past was trying to do it in the recipe or some 
other ordering problem.  I think part of it is that these are special 
since they use "export"

So now the question is which place them TARGET_*FLAGS or *FLAGS??

TARGET_* makes it clear we are modifying those flags.


Sau!
> p.
>
>
>
>

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Khem Raj]

On Jun 28, 2013, at 1:19 PM, Saul Wold <sgw@linux.intel.com> wrote:

> On 06/28/2013 12:51 PM, Phil Blundell wrote:
>> On Fri, 2013-06-28 at 12:23 -0700, Saul Wold wrote:
>>> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
>>> defined in the security_flags.inc and override the empty default.
>> 
>> Why can't security_flags.inc just append to CFLAGS and LDFLAGS
>> respectively, or some other set of variables that already exists?
>> 
> So, if I remember correctly there was issues with this because there are a number of packages that have to modify specifically the security related flags (see the list in security_flags.inc), the ordering/timing of being able to due that correctly did not allow for setting it directly in CFLAGS or TARGET_CFLAGS.

can you use append|prepend override ?

> 
>> Creating new variables in bitbake.conf does have a cost in terms of
>> parse time and memory footprint for every recipe.  If the variables are
>> referenced in ${CFLAGS} etc then it also adds an extra substitution
>> whenever CFLAGS is expanded.  The cost of those things isn't enormous,
>> but it isn't zero either and adding them isn't something that we should
>> do capriciously.
>> 
> I understand, and RP and I talked about this, we needed a separate variable to ensure the correct substitution occurred for those that needed to disable or remove certain flags.
> 
> Sau!
> 
> 
>> p.
>> 
>> 
>> 
>> 
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-core

Re: [PATCH 1/2 v2] bitbake.conf: Add SECURITY_*FLAGS overridable definition

[Khem Raj]

On Jun 28, 2013, at 12:51 PM, Phil Blundell <pb@pbcl.net> wrote:

> On Fri, 2013-06-28 at 12:23 -0700, Saul Wold wrote:
>> This will allow for SECURITY_CFLAGS and SECURITY_LDFLAGS to be
>> defined in the security_flags.inc and override the empty default.
> 
> Why can't security_flags.inc just append to CFLAGS and LDFLAGS
> respectively, or some other set of variables that already exists?
> 

It could help debugging metadata a bit if they are separate but appending to TARGET_FLAGS
in this inc file is not as bad an option

> Creating new variables in bitbake.conf does have a cost in terms of
> parse time and memory footprint for every recipe.  If the variables are
> referenced in ${CFLAGS} etc then it also adds an extra substitution
> whenever CFLAGS is expanded.  The cost of those things isn't enormous,
> but it isn't zero either and adding them isn't something that we should
> do capriciously.
> 
> p.
> 
> 
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-core