* [RFC] [PATCH] audit: log 32-bit socketcalls
@ 2017-01-12 12:36 Richard Guy Briggs
2017-01-12 21:32 ` Paul Moore
0 siblings, 1 reply; 3+ messages in thread
From: Richard Guy Briggs @ 2017-01-12 12:36 UTC (permalink / raw)
To: linux-kernel, linux-audit
Cc: Richard Guy Briggs, Kangkook Jee, Eric Paris, Paul Moore, Steve Grubb
32-bit socketcalls were not being logged by audit on x86_64 systems.
Log them.
See: https://github.com/linux-audit/audit-kernel/issues/14
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
net/compat.c | 18 ++++++++++++++++--
1 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/net/compat.c b/net/compat.c
index 1cd2ec0..86cacab 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -22,6 +22,7 @@
#include <linux/filter.h>
#include <linux/compat.h>
#include <linux/security.h>
+#include <linux/audit.h>
#include <linux/export.h>
#include <net/scm.h>
@@ -781,14 +782,27 @@ COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
{
+ unsigned int len, i;
int ret;
- u32 a[6];
+ u32 a[AUDITSC_ARGS];
+ unsigned long aa[AUDITSC_ARGS];
u32 a0, a1;
if (call < SYS_SOCKET || call > SYS_SENDMMSG)
return -EINVAL;
- if (copy_from_user(a, args, nas[call]))
+ len = nas[call];
+ if (len > sizeof(a))
+ return -EINVAL;
+
+ if (copy_from_user(a, args, len))
return -EFAULT;
+
+ for (i=0; i < len/sizeof(a[0]); i++)
+ aa[i] = (unsigned long)a[i];
+ ret = audit_socketcall(len/sizeof(a[0]), aa);
+ if (ret)
+ return ret;
+
a0 = a[0];
a1 = a[1];
--
1.7.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RFC] [PATCH] audit: log 32-bit socketcalls
2017-01-12 12:36 [RFC] [PATCH] audit: log 32-bit socketcalls Richard Guy Briggs
@ 2017-01-12 21:32 ` Paul Moore
2017-01-13 4:08 ` Richard Guy Briggs
0 siblings, 1 reply; 3+ messages in thread
From: Paul Moore @ 2017-01-12 21:32 UTC (permalink / raw)
To: Richard Guy Briggs; +Cc: linux-kernel, linux-audit
On Thu, Jan 12, 2017 at 7:36 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
> 32-bit socketcalls were not being logged by audit on x86_64 systems.
> Log them.
>
> See: https://github.com/linux-audit/audit-kernel/issues/14
>
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
> net/compat.c | 18 ++++++++++++++++--
> 1 files changed, 16 insertions(+), 2 deletions(-)
You should CC netdev on this patch; I'd also mention that you are
simply duplicating the normal socketcall() auditing in the compat
version (the only real difference being the argument size handling
workaround).
> diff --git a/net/compat.c b/net/compat.c
> index 1cd2ec0..86cacab 100644
> --- a/net/compat.c
> +++ b/net/compat.c
> @@ -22,6 +22,7 @@
> #include <linux/filter.h>
> #include <linux/compat.h>
> #include <linux/security.h>
> +#include <linux/audit.h>
> #include <linux/export.h>
>
> #include <net/scm.h>
> @@ -781,14 +782,27 @@ COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
>
> COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
> {
> + unsigned int len, i;
> int ret;
> - u32 a[6];
> + u32 a[AUDITSC_ARGS];
> + unsigned long aa[AUDITSC_ARGS];
> u32 a0, a1;
>
> if (call < SYS_SOCKET || call > SYS_SENDMMSG)
> return -EINVAL;
> - if (copy_from_user(a, args, nas[call]))
> + len = nas[call];
> + if (len > sizeof(a))
> + return -EINVAL;
> +
> + if (copy_from_user(a, args, len))
> return -EFAULT;
> +
> + for (i=0; i < len/sizeof(a[0]); i++)
> + aa[i] = (unsigned long)a[i];
It will be interesting to see if you get push back on this loop
outside of audit_socketcall(); folks may want to see it wrapped up
inside a audit_socketcall_compat() (or similar) function so it isn't
needlessly called in a number of cases. However, considering it is
compat code, and not the common case it may be okay.
> + ret = audit_socketcall(len/sizeof(a[0]), aa);
> + if (ret)
> + return ret;
> +
> a0 = a[0];
> a1 = a[1];
>
> --
> 1.7.1
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC] [PATCH] audit: log 32-bit socketcalls
2017-01-12 21:32 ` Paul Moore
@ 2017-01-13 4:08 ` Richard Guy Briggs
0 siblings, 0 replies; 3+ messages in thread
From: Richard Guy Briggs @ 2017-01-13 4:08 UTC (permalink / raw)
To: Paul Moore; +Cc: linux-kernel, linux-audit, netdev
On 2017-01-12 16:32, Paul Moore wrote:
> On Thu, Jan 12, 2017 at 7:36 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
> > 32-bit socketcalls were not being logged by audit on x86_64 systems.
> > Log them.
> >
> > See: https://github.com/linux-audit/audit-kernel/issues/14
> >
> > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > ---
> > net/compat.c | 18 ++++++++++++++++--
> > 1 files changed, 16 insertions(+), 2 deletions(-)
>
> You should CC netdev on this patch; I'd also mention that you are
> simply duplicating the normal socketcall() auditing in the compat
> version (the only real difference being the argument size handling
> workaround).
D'ho! Completely forgot about netdev.
I thought of mentioning the size handling in the description, but
figured it was somewhat obvious right in the code. I'll add a comment.
> > diff --git a/net/compat.c b/net/compat.c
> > index 1cd2ec0..86cacab 100644
> > --- a/net/compat.c
> > +++ b/net/compat.c
> > @@ -22,6 +22,7 @@
> > #include <linux/filter.h>
> > #include <linux/compat.h>
> > #include <linux/security.h>
> > +#include <linux/audit.h>
> > #include <linux/export.h>
> >
> > #include <net/scm.h>
> > @@ -781,14 +782,27 @@ COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
> >
> > COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
> > {
> > + unsigned int len, i;
> > int ret;
> > - u32 a[6];
> > + u32 a[AUDITSC_ARGS];
> > + unsigned long aa[AUDITSC_ARGS];
> > u32 a0, a1;
> >
> > if (call < SYS_SOCKET || call > SYS_SENDMMSG)
> > return -EINVAL;
> > - if (copy_from_user(a, args, nas[call]))
> > + len = nas[call];
> > + if (len > sizeof(a))
> > + return -EINVAL;
> > +
> > + if (copy_from_user(a, args, len))
> > return -EFAULT;
> > +
> > + for (i=0; i < len/sizeof(a[0]); i++)
> > + aa[i] = (unsigned long)a[i];
>
> It will be interesting to see if you get push back on this loop
> outside of audit_socketcall(); folks may want to see it wrapped up
> inside a audit_socketcall_compat() (or similar) function so it isn't
> needlessly called in a number of cases. However, considering it is
> compat code, and not the common case it may be okay.
I thought about this, and was thinking a check of !audit_dummy_context()
here might be a solution, but audit_socketcall_compat is a much cleaner
idea. I did also consider that it is compat code that won't have a lot
of performance nerds screaming, but that's no excuse...
> > + ret = audit_socketcall(len/sizeof(a[0]), aa);
> > + if (ret)
> > + return ret;
> > +
> > a0 = a[0];
> > a1 = a[1];
> >
> > --
> > 1.7.1
>
> --
> paul moore
> www.paul-moore.com
- RGB
--
Richard Guy Briggs <rgb@redhat.com>
Kernel Security Engineering, Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635
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