Re: [PATCH V2 2/6] audit: log namespace serial numbers

[Eric Paris <eparis-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Fri, 2014-05-09 at 20:27 -0400, Richard Guy Briggs wrote:
> Log the namespace serial numbers of a task in audit_log_task_info() which
> is used by syscall audits, among others..
> 
> Idea first presented:
> 	https://www.redhat.com/archives/linux-audit/2013-March/msg00020.html
> 
> Typical output format would look something like:
> 	        type=SYSCALL msg=audit(1399651071.433:72): arch=c000003e syscall=272 success=yes exit=0 a0=40000000 a1=ffffffffffffffff a2=0 a3=22 items=0 ppid=1 pid=483 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="(t-daemon)" exe="/usr/lib/systemd/systemd" netns=97 utsns=2 ipcns=1 pidns=4 userns=3 mntns=5 subj=system_u:system_r:init_t:s0 key=(null)
> 
> The serial numbers are printed in hex.
> 
> Suggested-by: Aristeu Rozanski <arozansk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Acked-by: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
> ---
>  include/linux/audit.h |    7 +++++++
>  kernel/audit.c        |   38 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 45 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 22cfddb..0ef404a 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -101,6 +101,13 @@ extern int __weak audit_classify_compat_syscall(int abi, unsigned syscall);
>  struct filename;
>  
>  extern void audit_log_session_info(struct audit_buffer *ab);
> +#ifdef CONFIG_NAMESPACES
> +extern void audit_log_namespace_info(struct audit_buffer *ab, struct task_struct *tsk);
> +#else
> +void audit_log_namespace_info(struct audit_buffer *ab, struct task_struct *tsk)
> +{
> +}
> +#endif
>  
>  #ifdef CONFIG_AUDIT_COMPAT_GENERIC
>  #define audit_is_compat(arch)  (!((arch) & __AUDIT_ARCH_64BIT))
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 59c0bbe..fe783ad 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -64,7 +64,15 @@
>  #endif
>  #include <linux/freezer.h>
>  #include <linux/tty.h>
> +#include <linux/nsproxy.h>
> +#include <linux/utsname.h>
> +#include <linux/ipc_namespace.h>
> +#include "../fs/mount.h"

I don't think such an include is ever a good idea and likely to get us
SHOT by Viro...

Why do we need this include?

> +#include <linux/mount.h>
> +#include <linux/mnt_namespace.h>
>  #include <linux/pid_namespace.h>
> +#include <net/net_namespace.h>
> +#include <linux/user_namespace.h>
>  #include <net/netns/generic.h>
>  
>  #include "audit.h"
> @@ -1617,6 +1625,35 @@ void audit_log_session_info(struct audit_buffer *ab)
>  	audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
>  }
>  
> +#ifdef CONFIG_NAMESPACES
> +void audit_log_namespace_info(struct audit_buffer *ab, struct task_struct *tsk)
> +{
> +	struct nsproxy *nsproxy;
> +
> +	rcu_read_lock();
> +	nsproxy = task_nsproxy(tsk);
> +	if (nsproxy != NULL) {
> +		audit_log_format(ab, " mntns=%llx", nsproxy->mnt_ns->serial_num);
> +#ifdef CONFIG_NET_NS
> +		audit_log_format(ab, " netns=%llx", nsproxy->net_ns->serial_num);
> +#endif
> +#ifdef CONFIG_UTS_NS
> +		audit_log_format(ab, " utsns=%llx", nsproxy->uts_ns->serial_num);
> +#endif
> +#ifdef CONFIG_IPC_NS
> +		audit_log_format(ab, " ipcns=%llx", nsproxy->ipc_ns->serial_num);
> +#endif
> +	}
> +#ifdef CONFIG_PID_NS
> +	audit_log_format(ab, " pidns=%llx", task_active_pid_ns(tsk)->serial_num);
> +#endif
> +#ifdef CONFIG_USER_NS
> +	audit_log_format(ab, " userns=%llx", task_cred_xxx(tsk, user_ns)->serial_num);
> +#endif
> +	rcu_read_unlock();
> +}
> +#endif /* CONFIG_NAMESPACES */
> +
>  void audit_log_key(struct audit_buffer *ab, char *key)
>  {
>  	audit_log_format(ab, " key=");
> @@ -1861,6 +1898,7 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
>  		up_read(&mm->mmap_sem);
>  	} else
>  		audit_log_format(ab, " exe=(null)");
> +	audit_log_namespace_info(ab, tsk);
>  	audit_log_task_context(ab);
>  }
>  EXPORT_SYMBOL(audit_log_task_info);