Re: [PATCH V2] audit: log module name on init_module

[Steve Grubb <sgrubb@redhat.com>]

On Monday, February 13, 2017 4:20:55 PM EST Paul Moore wrote:
> On Sat, Feb 4, 2017 at 1:10 PM, Richard Guy Briggs <rgb@redhat.com> wrote:
> > This adds a new auxiliary record MODULE_INIT to the SYSCALL event.
> > 
> > We get finit_module for free since it made most sense to hook this in to
> > load_module().
> > 
> > https://github.com/linux-audit/audit-kernel/issues/7
> > https://github.com/linux-audit/audit-kernel/wiki/RFE-Module-load-record-fo
> > rmat
> Correction for the record:
> 
> *
> https://github.com/linux-audit/audit-kernel/wiki/RFE-Module-Load-Record-For
> mat
> 
> [NOTE: don't resend please, I'll fix this when merging]

OK. Support was added to user space for this record. While doing this, I 
wondered if we also get this auxiliary record when unloading a module?

Thanks,
-Steve

> > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > ---
> > 
> >  include/linux/audit.h      |   12 ++++++++++++
> >  include/uapi/linux/audit.h |    1 +
> >  kernel/audit.h             |    3 +++
> >  kernel/auditsc.c           |   14 ++++++++++++++
> >  kernel/module.c            |    5 ++++-
> >  5 files changed, 34 insertions(+), 1 deletions(-)
> 
> This patch looks fine to me, and due to lack of comments I'm going to
> assume that Jessica is okay with the kernel/module.c portions of this
> patch.  Normally this would be too close to the merge window, but this
> patch is trivial and since it is new functionality it is unlikely to
> cause any regressions so I'm going to merge it into audit/next now.
> 
> > diff --git a/include/linux/audit.h b/include/linux/audit.h
> > index 2be99b2..aba3a26 100644
> > --- a/include/linux/audit.h
> > +++ b/include/linux/audit.h
> > @@ -360,6 +360,7 @@ extern int __audit_log_bprm_fcaps(struct linux_binprm
> > *bprm,> 
> >                                   const struct cred *old);
> >  
> >  extern void __audit_log_capset(const struct cred *new, const struct cred
> >  *old); extern void __audit_mmap_fd(int fd, int flags);
> > 
> > +extern void __audit_log_kern_module(char *name);
> > 
> >  static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
> >  {
> > 
> > @@ -450,6 +451,12 @@ static inline void audit_mmap_fd(int fd, int flags)
> > 
> >                 __audit_mmap_fd(fd, flags);
> >  
> >  }
> > 
> > +static inline void audit_log_kern_module(char *name)
> > +{
> > +       if (!audit_dummy_context())
> > +               __audit_log_kern_module(name);
> > +}
> > +
> > 
> >  extern int audit_n_rules;
> >  extern int audit_signals;
> >  #else /* CONFIG_AUDITSYSCALL */
> > 
> > @@ -561,6 +568,11 @@ static inline void audit_log_capset(const struct cred
> > *new,> 
> >  { }
> >  static inline void audit_mmap_fd(int fd, int flags)
> >  { }
> > 
> > +
> > +static inline void audit_log_kern_module(char *name)
> > +{
> > +}
> > +
> > 
> >  static inline void audit_ptrace(struct task_struct *t)
> >  { }
> >  #define audit_n_rules 0
> > 
> > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> > index 3f24110..3c02bb2 100644
> > --- a/include/uapi/linux/audit.h
> > +++ b/include/uapi/linux/audit.h
> > @@ -111,6 +111,7 @@
> > 
> >  #define AUDIT_PROCTITLE                1327    /* Proctitle emit event */
> >  #define AUDIT_FEATURE_CHANGE   1328    /* audit log listing feature
> >  changes */ #define AUDIT_REPLACE          1329    /* Replace auditd if
> >  this packet unanswerd */> 
> > +#define AUDIT_KERN_MODULE      1330    /* Kernel Module events */
> > 
> >  #define AUDIT_AVC              1400    /* SE Linux avc denial or grant */
> >  #define AUDIT_SELINUX_ERR      1401    /* Internal SE Linux Errors */
> > 
> > diff --git a/kernel/audit.h b/kernel/audit.h
> > index 431444c..144b7eb 100644
> > --- a/kernel/audit.h
> > +++ b/kernel/audit.h
> > @@ -199,6 +199,9 @@ struct audit_context {
> > 
> >                 struct {
> >                 
> >                         int                     argc;
> >                 
> >                 } execve;
> > 
> > +               struct {
> > +                       char                    *name;
> > +               } module;
> > 
> >         };
> >         int fds[2];
> >         struct audit_proctitle proctitle;
> > 
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index bb5f504..bde3aac 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -1268,6 +1268,11 @@ static void show_special(struct audit_context
> > *context, int *call_panic)> 
> >         case AUDIT_EXECVE: {
> >         
> >                 audit_log_execve_info(context, &ab);
> >                 break; }
> > 
> > +       case AUDIT_KERN_MODULE:
> > +               audit_log_format(ab, "name=");
> > +               audit_log_untrustedstring(ab, context->module.name);
> > +               kfree(context->module.name);
> > +               break;
> > 
> >         }
> >         audit_log_end(ab);
> >  
> >  }
> > 
> > @@ -2368,6 +2373,15 @@ void __audit_mmap_fd(int fd, int flags)
> > 
> >         context->type = AUDIT_MMAP;
> >  
> >  }
> > 
> > +void __audit_log_kern_module(char *name)
> > +{
> > +       struct audit_context *context = current->audit_context;
> > +
> > +       context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
> > +       strcpy(context->module.name, name);
> > +       context->type = AUDIT_KERN_MODULE;
> > +}
> > +
> > 
> >  static void audit_log_task(struct audit_buffer *ab)
> >  {
> >  
> >         kuid_t auid, uid;
> > 
> > diff --git a/kernel/module.c b/kernel/module.c
> > index 529efae..5432dbe 100644
> > --- a/kernel/module.c
> > +++ b/kernel/module.c
> > @@ -61,6 +61,7 @@
> > 
> >  #include <linux/pfn.h>
> >  #include <linux/bsearch.h>
> >  #include <linux/dynamic_debug.h>
> > 
> > +#include <linux/audit.h>
> > 
> >  #include <uapi/linux/module.h>
> >  #include "module-internal.h"
> > 
> > @@ -3593,6 +3594,8 @@ static int load_module(struct load_info *info, const
> > char __user *uargs,> 
> >                 goto free_copy;
> >         
> >         }
> > 
> > +       audit_log_kern_module(mod->name);
> > +
> > 
> >         /* Reserve our place in the list. */
> >         err = add_unformed_module(mod);
> >         if (err)
> > 
> > @@ -3681,7 +3684,7 @@ static int load_module(struct load_info *info, const
> > char __user *uargs,> 
> >                        mod->name, after_dashes);
> >         
> >         }
> > 
> > -       /* Link in to syfs. */
> > +       /* Link in to sysfs. */
> > 
> >         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
> >         if (err < 0)
> >         
> >                 goto coming_cleanup;
> > 
> > --
> > 1.7.1
> > 
> > --
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> > Linux-audit@redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-audit