The AUDIT_SECCOMP record looks something like this:
type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
To see the event, compile this test.c program:
=====
int main(void)
{
return seccomp_load(seccomp_init(SCMP_ACT_KILL));
}
=====
gcc -g test.c -o test -lseccomp
After running the program, find the record by: ausearch --start recent -m SECCOMP -i
---
kernel/auditsc.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 6874c1f..c464d44 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
return;
audit_log_task(ab);
audit_log_format(ab, " sig=%ld", signr);
+ audit_log_format(ab, " arch=%x", current->audit_context->arch);
audit_log_format(ab, " syscall=%ld", syscall);
audit_log_format(ab, " compat=%d", is_compat_task());
audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
--
1.7.1
On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> The AUDIT_SECCOMP record looks something like this:
>
> type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
>
> In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
>
> To see the event, compile this test.c program:
>
> =====
> int main(void)
> {
> return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> }
> =====
>
> gcc -g test.c -o test -lseccomp
>
> After running the program, find the record by: ausearch --start recent -m SECCOMP -i
> ---
> kernel/auditsc.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 6874c1f..c464d44 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
> return;
> audit_log_task(ab);
> audit_log_format(ab, " sig=%ld", signr);
> + audit_log_format(ab, " arch=%x", current->audit_context->arch);
What happens if the task does not have current->audit_context allocated?
Seems possible if signr is non-zero...
> audit_log_format(ab, " syscall=%ld", syscall);
> audit_log_format(ab, " compat=%d", is_compat_task());
> audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
On 14/02/14, Eric Paris wrote:
> On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> > The AUDIT_SECCOMP record looks something like this:
> >
> > type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
> >
> > In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
> >
> > To see the event, compile this test.c program:
> >
> > =====
> > int main(void)
> > {
> > return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> > }
> > =====
> >
> > gcc -g test.c -o test -lseccomp
> >
> > After running the program, find the record by: ausearch --start recent -m SECCOMP -i
> > ---
> > kernel/auditsc.c | 1 +
> > 1 files changed, 1 insertions(+), 0 deletions(-)
> >
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index 6874c1f..c464d44 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
> > return;
> > audit_log_task(ab);
> > audit_log_format(ab, " sig=%ld", signr);
> > + audit_log_format(ab, " arch=%x", current->audit_context->arch);
>
>
> What happens if the task does not have current->audit_context allocated?
> Seems possible if signr is non-zero...
I had assumed that since we got this far, that there was an audit
context. This was my first patch:
---
kernel/auditsc.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 6874c1f..ef16e02 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2406,12 +2406,19 @@ void audit_core_dumps(long signr)
void __audit_seccomp(unsigned long syscall, long signr, int code)
{
struct audit_buffer *ab;
+ //struct audit_context *context audit_get_context(current, 0,
0);
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
if (unlikely(!ab))
return;
audit_log_task(ab);
audit_log_format(ab, " sig=%ld", signr);
+ //audit_log_format(ab, " arch=");
+ //if (context)
+ //audit_log_format(ab, "(null)");
+ //else
+ //audit_log_format(ab, "%x", context->arch);
+ audit_log_format(ab, " arch=%x", current->audit_context->arch);
audit_log_format(ab, " syscall=%ld", syscall);
audit_log_format(ab, " compat=%d", is_compat_task());
audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
--
1.7.1
> > audit_log_format(ab, " syscall=%ld", syscall);
> > audit_log_format(ab, " compat=%d", is_compat_task());
> > audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
>
>
- RGB
--
Richard Guy Briggs <[email protected]>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
On 14/02/14, Richard Guy Briggs wrote:
> On 14/02/14, Eric Paris wrote:
> > On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> > > The AUDIT_SECCOMP record looks something like this:
> > >
> > > type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
> > >
> > > In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
> > >
> > > To see the event, compile this test.c program:
> > >
> > > =====
> > > int main(void)
> > > {
> > > return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> > > }
> > > =====
> > >
> > > gcc -g test.c -o test -lseccomp
> > >
> > > After running the program, find the record by: ausearch --start recent -m SECCOMP -i
> > > ---
> > > kernel/auditsc.c | 1 +
> > > 1 files changed, 1 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > index 6874c1f..c464d44 100644
> > > --- a/kernel/auditsc.c
> > > +++ b/kernel/auditsc.c
> > > @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > return;
> > > audit_log_task(ab);
> > > audit_log_format(ab, " sig=%ld", signr);
> > > + audit_log_format(ab, " arch=%x", current->audit_context->arch);
> >
> >
> > What happens if the task does not have current->audit_context allocated?
> > Seems possible if signr is non-zero...
>
> I had assumed that since we got this far, that there was an audit
> context. This was my first patch:
Sorry, pulled the trigger too fast:
---
kernel/auditsc.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 6874c1f..3023d03 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
void __audit_seccomp(unsigned long syscall, long signr, int code)
{
struct audit_buffer *ab;
+ struct audit_context *context audit_get_context(current, 0, 0);
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
if (unlikely(!ab))
return;
audit_log_task(ab);
audit_log_format(ab, " sig=%ld", signr);
+ audit_log_format(ab, " arch=");
+ if (context)
+ audit_log_format(ab, "(null)");
+ else
+ audit_log_format(ab, "%x", context->arch);
audit_log_format(ab, " syscall=%ld", syscall);
audit_log_format(ab, " compat=%d", is_compat_task());
audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
--
1.7.1
> - RGB
- RGB
--
Richard Guy Briggs <[email protected]>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
On Fri, 2014-02-14 at 15:52 -0500, Richard Guy Briggs wrote:
> On 14/02/14, Richard Guy Briggs wrote:
> > On 14/02/14, Eric Paris wrote:
> > > On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> > > > The AUDIT_SECCOMP record looks something like this:
> > > >
> > > > type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
> > > >
> > > > In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
> > > >
> > > > To see the event, compile this test.c program:
> > > >
> > > > =====
> > > > int main(void)
> > > > {
> > > > return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> > > > }
> > > > =====
> > > >
> > > > gcc -g test.c -o test -lseccomp
> > > >
> > > > After running the program, find the record by: ausearch --start recent -m SECCOMP -i
> > > > ---
> > > > kernel/auditsc.c | 1 +
> > > > 1 files changed, 1 insertions(+), 0 deletions(-)
> > > >
> > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > > index 6874c1f..c464d44 100644
> > > > --- a/kernel/auditsc.c
> > > > +++ b/kernel/auditsc.c
> > > > @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > > return;
> > > > audit_log_task(ab);
> > > > audit_log_format(ab, " sig=%ld", signr);
> > > > + audit_log_format(ab, " arch=%x", current->audit_context->arch);
> > >
> > >
> > > What happens if the task does not have current->audit_context allocated?
> > > Seems possible if signr is non-zero...
> >
> > I had assumed that since we got this far, that there was an audit
> > context. This was my first patch:
>
> Sorry, pulled the trigger too fast:
>
> ---
> kernel/auditsc.c | 6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 6874c1f..3023d03 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> void __audit_seccomp(unsigned long syscall, long signr, int code)
> {
> struct audit_buffer *ab;
> + struct audit_context *context audit_get_context(current, 0, 0);
missing '=' but this isn't what audit_get_context() does... it's
crappy naming... I'd think a combo of audit_dummy_context() and
current->audit_context would be most appropriate.
> ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> if (unlikely(!ab))
> return;
> audit_log_task(ab);
> audit_log_format(ab, " sig=%ld", signr);
> + audit_log_format(ab, " arch=");
> + if (context)
> + audit_log_format(ab, "(null)");
> + else
> + audit_log_format(ab, "%x", context->arch);
> audit_log_format(ab, " syscall=%ld", syscall);
> audit_log_format(ab, " compat=%d", is_compat_task());
> audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
On 14/02/14, Eric Paris wrote:
> On Fri, 2014-02-14 at 15:52 -0500, Richard Guy Briggs wrote:
> > On 14/02/14, Richard Guy Briggs wrote:
> > > On 14/02/14, Eric Paris wrote:
> > > > On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> > > > > The AUDIT_SECCOMP record looks something like this:
> > > > >
> > > > > type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
> > > > >
> > > > > In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
> > > > >
> > > > > To see the event, compile this test.c program:
> > > > >
> > > > > =====
> > > > > int main(void)
> > > > > {
> > > > > return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> > > > > }
> > > > > =====
> > > > >
> > > > > gcc -g test.c -o test -lseccomp
> > > > >
> > > > > After running the program, find the record by: ausearch --start recent -m SECCOMP -i
> > > > > ---
> > > > > kernel/auditsc.c | 1 +
> > > > > 1 files changed, 1 insertions(+), 0 deletions(-)
> > > > >
> > > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > > > index 6874c1f..c464d44 100644
> > > > > --- a/kernel/auditsc.c
> > > > > +++ b/kernel/auditsc.c
> > > > > @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > > > return;
> > > > > audit_log_task(ab);
> > > > > audit_log_format(ab, " sig=%ld", signr);
> > > > > + audit_log_format(ab, " arch=%x", current->audit_context->arch);
> > > >
> > > >
> > > > What happens if the task does not have current->audit_context allocated?
> > > > Seems possible if signr is non-zero...
> > >
> > > I had assumed that since we got this far, that there was an audit
> > > context. This was my first patch:
> >
> > Sorry, pulled the trigger too fast:
> >
> > ---
> > kernel/auditsc.c | 6 ++++++
> > 1 files changed, 6 insertions(+), 0 deletions(-)
> >
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index 6874c1f..3023d03 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> > void __audit_seccomp(unsigned long syscall, long signr, int code)
> > {
> > struct audit_buffer *ab;
> > + struct audit_context *context audit_get_context(current, 0, 0);
>
> missing '=' but this isn't what audit_get_context() does... it's
> crappy naming... I'd think a combo of audit_dummy_context() and
> current->audit_context would be most appropriate.
Ok. I think I finally understand audit_dummy_context(). Thanks for the
hint. However, it appears it is not useful in this sitation, since if
there is an audit_context, even a dummy context, it appears arch is
filled in.
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
@@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
void __audit_seccomp(unsigned long syscall, long signr, int code)
{
struct audit_buffer *ab;
+ struct audit_context *context = current->audit_context;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
if (unlikely(!ab))
return;
audit_log_task(ab);
audit_log_format(ab, " sig=%ld", signr);
+ audit_log_format(ab, " arch=");
+ if (context)
+ audit_log_format(ab, "%x", context->arch);
+ else
+ audit_log_format(ab, "(null)");
audit_log_format(ab, " syscall=%ld", syscall);
audit_log_format(ab, " compat=%d", is_compat_task());
audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
- RGB
--
Richard Guy Briggs <[email protected]>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
On Tue, 2014-02-18 at 15:50 -0500, Richard Guy Briggs wrote:
> On 14/02/14, Eric Paris wrote:
> > On Fri, 2014-02-14 at 15:52 -0500, Richard Guy Briggs wrote:
> > > On 14/02/14, Richard Guy Briggs wrote:
> > > > On 14/02/14, Eric Paris wrote:
> > > > > On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> > > > > > The AUDIT_SECCOMP record looks something like this:
> > > > > >
> > > > > > type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325 gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0 pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89 code=0x0
> > > > > >
> > > > > > In order to determine what syscall 231 maps to, we need to have the arch= field right before it.
> > > > > >
> > > > > > To see the event, compile this test.c program:
> > > > > >
> > > > > > =====
> > > > > > int main(void)
> > > > > > {
> > > > > > return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> > > > > > }
> > > > > > =====
> > > > > >
> > > > > > gcc -g test.c -o test -lseccomp
> > > > > >
> > > > > > After running the program, find the record by: ausearch --start recent -m SECCOMP -i
> > > > > > ---
> > > > > > kernel/auditsc.c | 1 +
> > > > > > 1 files changed, 1 insertions(+), 0 deletions(-)
> > > > > >
> > > > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > > > > index 6874c1f..c464d44 100644
> > > > > > --- a/kernel/auditsc.c
> > > > > > +++ b/kernel/auditsc.c
> > > > > > @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > > > > return;
> > > > > > audit_log_task(ab);
> > > > > > audit_log_format(ab, " sig=%ld", signr);
> > > > > > + audit_log_format(ab, " arch=%x", current->audit_context->arch);
> > > > >
> > > > >
> > > > > What happens if the task does not have current->audit_context allocated?
> > > > > Seems possible if signr is non-zero...
> > > >
> > > > I had assumed that since we got this far, that there was an audit
> > > > context. This was my first patch:
> > >
> > > Sorry, pulled the trigger too fast:
> > >
> > > ---
> > > kernel/auditsc.c | 6 ++++++
> > > 1 files changed, 6 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > index 6874c1f..3023d03 100644
> > > --- a/kernel/auditsc.c
> > > +++ b/kernel/auditsc.c
> > > @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> > > void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > {
> > > struct audit_buffer *ab;
> > > + struct audit_context *context audit_get_context(current, 0, 0);
> >
> > missing '=' but this isn't what audit_get_context() does... it's
> > crappy naming... I'd think a combo of audit_dummy_context() and
> > current->audit_context would be most appropriate.
>
> Ok. I think I finally understand audit_dummy_context(). Thanks for the
> hint. However, it appears it is not useful in this sitation, since if
> there is an audit_context, even a dummy context, it appears arch is
> filled in.
get a good commit message and feel free to add my Acked-by.
-Eric
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> void __audit_seccomp(unsigned long syscall, long signr, int code)
> {
> struct audit_buffer *ab;
> + struct audit_context *context = current->audit_context;
>
> ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> if (unlikely(!ab))
> return;
> audit_log_task(ab);
> audit_log_format(ab, " sig=%ld", signr);
> + audit_log_format(ab, " arch=");
> + if (context)
> + audit_log_format(ab, "%x", context->arch);
> + else
> + audit_log_format(ab, "(null)");
> audit_log_format(ab, " syscall=%ld", syscall);
> audit_log_format(ab, " compat=%d", is_compat_task());
> audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
>
> - RGB
>
> --
> Richard Guy Briggs <[email protected]>
> Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
> Remote, Ottawa, Canada
> Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
On Tuesday, February 18, 2014 03:50:44 PM Richard Guy Briggs wrote:
> > missing '=' but this isn't what audit_get_context() does... it's
> > crappy naming... I'd think a combo of audit_dummy_context() and
> > current->audit_context would be most appropriate.
>
> Ok. I think I finally understand audit_dummy_context(). Thanks for the
> hint. However, it appears it is not useful in this sitation, since if
> there is an audit_context, even a dummy context, it appears arch is
> filled in.
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> void __audit_seccomp(unsigned long syscall, long signr, int code)
> {
> struct audit_buffer *ab;
> + struct audit_context *context = current->audit_context;
>
> ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> if (unlikely(!ab))
> return;
> audit_log_task(ab);
> audit_log_format(ab, " sig=%ld", signr);
> + audit_log_format(ab, " arch=");
> + if (context)
> + audit_log_format(ab, "%x", context->arch);
> + else
> + audit_log_format(ab, "(null)");
> audit_log_format(ab, " syscall=%ld", syscall);
> audit_log_format(ab, " compat=%d", is_compat_task());
> audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
Is there anything that could be passed by the caller that might identify the
syscall ABI when this call was blocked? '(null)' still makes syscall number
uninterpretable.
-Steve
On 14/02/18, Steve Grubb wrote:
> On Tuesday, February 18, 2014 03:50:44 PM Richard Guy Briggs wrote:
> > > missing '=' but this isn't what audit_get_context() does... it's
> > > crappy naming... I'd think a combo of audit_dummy_context() and
> > > current->audit_context would be most appropriate.
> >
> > Ok. I think I finally understand audit_dummy_context(). Thanks for the
> > hint. However, it appears it is not useful in this sitation, since if
> > there is an audit_context, even a dummy context, it appears arch is
> > filled in.
> >
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> > void __audit_seccomp(unsigned long syscall, long signr, int code)
> > {
> > struct audit_buffer *ab;
> > + struct audit_context *context = current->audit_context;
> >
> > ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> > if (unlikely(!ab))
> > return;
> > audit_log_task(ab);
> > audit_log_format(ab, " sig=%ld", signr);
> > + audit_log_format(ab, " arch=");
> > + if (context)
> > + audit_log_format(ab, "%x", context->arch);
> > + else
> > + audit_log_format(ab, "(null)");
> > audit_log_format(ab, " syscall=%ld", syscall);
> > audit_log_format(ab, " compat=%d", is_compat_task());
> > audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
>
> Is there anything that could be passed by the caller that might identify the
> syscall ABI when this call was blocked? '(null)' still makes syscall number
> uninterpretable.
This is the way it is done in the existing record that prints a syscall
record in audit_log_exit().
It is set by the arch-dependent assembler linkage for
__audit_syscall_entry() or set by the arch-dependent ptrace code that
calls audit_syscall_entry(). In some arches there are a couple of
choices.
To pass this in to __audit_seccomp() as an arg, I'd have to add that arg
to:
__audit_seccomp()
audit_seccomp()
__secure_computing()
secure_computing()
As you've pointed out in IRC, there is a syscall_get_arch(current, regs)
that could be used to get the arch when an audit context is not yet created.
I was just looking for something like that... I am noticing that all
arches call a variant of syscall_trace_enter() which first calls
secure_computing() [which eventually calls __audit_seccomp()] *before*
calling audit_syscall_entry() [which eventually sets context->arch]. So
I'm not sure how task->audit_context->arch got set... Perhaps
__audit_syscall_entry() should just call syscall_get_arch() instead of
lugging it through the stack like it presently does.
Is this going to give the same information? (I guess I should be able
to answer that question...)
> -Steve
- RGB
--
Richard Guy Briggs <[email protected]>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
On 14/02/18, Richard Guy Briggs wrote:
> On 14/02/18, Steve Grubb wrote:
> > On Tuesday, February 18, 2014 03:50:44 PM Richard Guy Briggs wrote:
> > > > missing '=' but this isn't what audit_get_context() does... it's
> > > > crappy naming... I'd think a combo of audit_dummy_context() and
> > > > current->audit_context would be most appropriate.
> > >
> > > Ok. I think I finally understand audit_dummy_context(). Thanks for the
> > > hint. However, it appears it is not useful in this sitation, since if
> > > there is an audit_context, even a dummy context, it appears arch is
> > > filled in.
> > >
> > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> > > void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > {
> > > struct audit_buffer *ab;
> > > + struct audit_context *context = current->audit_context;
> > >
> > > ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> > > if (unlikely(!ab))
> > > return;
> > > audit_log_task(ab);
> > > audit_log_format(ab, " sig=%ld", signr);
> > > + audit_log_format(ab, " arch=");
> > > + if (context)
> > > + audit_log_format(ab, "%x", context->arch);
> > > + else
> > > + audit_log_format(ab, "(null)");
> > > audit_log_format(ab, " syscall=%ld", syscall);
> > > audit_log_format(ab, " compat=%d", is_compat_task());
> > > audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
> >
> > Is there anything that could be passed by the caller that might identify the
> > syscall ABI when this call was blocked? '(null)' still makes syscall number
> > uninterpretable.
>
> This is the way it is done in the existing record that prints a syscall
> record in audit_log_exit().
>
> It is set by the arch-dependent assembler linkage for
> __audit_syscall_entry() or set by the arch-dependent ptrace code that
> calls audit_syscall_entry(). In some arches there are a couple of
> choices.
>
>
> To pass this in to __audit_seccomp() as an arg, I'd have to add that arg
> to:
> __audit_seccomp()
> audit_seccomp()
> __secure_computing()
> secure_computing()
>
>
> As you've pointed out in IRC, there is a syscall_get_arch(current, regs)
> that could be used to get the arch when an audit context is not yet created.
s390x architecture doesn't have it defined. :(
> I was just looking for something like that... I am noticing that all
> arches call a variant of syscall_trace_enter() which first calls
> secure_computing() [which eventually calls __audit_seccomp()] *before*
> calling audit_syscall_entry() [which eventually sets context->arch]. So
> I'm not sure how task->audit_context->arch got set... Perhaps
> __audit_syscall_entry() should just call syscall_get_arch() instead of
> lugging it through the stack like it presently does.
>
> Is this going to give the same information? (I guess I should be able
> to answer that question...)
>
> > -Steve
>
> - RGB
- RGB
--
Richard Guy Briggs <[email protected]>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
On 14/02/19, Richard Guy Briggs wrote:
> On 14/02/18, Richard Guy Briggs wrote:
> > On 14/02/18, Steve Grubb wrote:
> > > On Tuesday, February 18, 2014 03:50:44 PM Richard Guy Briggs wrote:
> > > > > missing '=' but this isn't what audit_get_context() does... it's
> > > > > crappy naming... I'd think a combo of audit_dummy_context() and
> > > > > current->audit_context would be most appropriate.
> > > >
> > > > Ok. I think I finally understand audit_dummy_context(). Thanks for the
> > > > hint. However, it appears it is not useful in this sitation, since if
> > > > there is an audit_context, even a dummy context, it appears arch is
> > > > filled in.
> > > >
> > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > > @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> > > > void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > > {
> > > > struct audit_buffer *ab;
> > > > + struct audit_context *context = current->audit_context;
> > > >
> > > > ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> > > > if (unlikely(!ab))
> > > > return;
> > > > audit_log_task(ab);
> > > > audit_log_format(ab, " sig=%ld", signr);
> > > > + audit_log_format(ab, " arch=");
> > > > + if (context)
> > > > + audit_log_format(ab, "%x", context->arch);
> > > > + else
> > > > + audit_log_format(ab, "(null)");
> > > > audit_log_format(ab, " syscall=%ld", syscall);
> > > > audit_log_format(ab, " compat=%d", is_compat_task());
> > > > audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
> > >
> > > Is there anything that could be passed by the caller that might identify the
> > > syscall ABI when this call was blocked? '(null)' still makes syscall number
> > > uninterpretable.
> >
> > This is the way it is done in the existing record that prints a syscall
> > record in audit_log_exit().
> >
> > It is set by the arch-dependent assembler linkage for
> > __audit_syscall_entry() or set by the arch-dependent ptrace code that
> > calls audit_syscall_entry(). In some arches there are a couple of
> > choices.
> >
> >
> > To pass this in to __audit_seccomp() as an arg, I'd have to add that arg
> > to:
> > __audit_seccomp()
> > audit_seccomp()
> > __secure_computing()
> > secure_computing()
> >
> >
> > As you've pointed out in IRC, there is a syscall_get_arch(current, regs)
> > that could be used to get the arch when an audit context is not yet created.
>
> s390x architecture doesn't have it defined. :(
It is defined, but is having trouble finding it...
> > I was just looking for something like that... I am noticing that all
> > arches call a variant of syscall_trace_enter() which first calls
> > secure_computing() [which eventually calls __audit_seccomp()] *before*
> > calling audit_syscall_entry() [which eventually sets context->arch]. So
> > I'm not sure how task->audit_context->arch got set... Perhaps
> > __audit_syscall_entry() should just call syscall_get_arch() instead of
> > lugging it through the stack like it presently does.
> >
> > Is this going to give the same information? (I guess I should be able
> > to answer that question...)
> >
> > > -Steve
> >
> > - RGB
>
> - RGB
- RGB
--
Richard Guy Briggs <[email protected]>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545