Messages in this thread | | | Date | Thu, 12 Jan 2017 23:08:18 -0500 | From | Richard Guy Briggs <> | Subject | Re: [RFC] [PATCH] audit: log 32-bit socketcalls |
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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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