Re: [PATCH ghak90 (was ghak32) V4 05/10] audit: add support for non-syscall auxiliary records

On Sun, Aug 5, 2018 at 4:33 AM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > Standalone audit records have the timestamp and serial number generated > on the fly and as such are unique, making them standalone. This new > function audit_alloc_local() generates a local audit context that will > be used only for a standalone record and its auxiliary record(s). The > context is discarded immediately after the local associated records are > produced. > > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > Acked-by: Serge Hallyn <serge(a)hallyn.com&gt; > --- > include/linux/audit.h | 8 ++++++++ > kernel/audit.h | 1 + > kernel/auditsc.c | 33 ++++++++++++++++++++++++++++----- > 3 files changed, 37 insertions(+), 5 deletions(-) I'm not in love with the local flag, and the whole local context in general, but that's a larger discussion and not something I want to force on this patchset; we can fix it later.

I think this patch looks fine, but it seems a bit odd standalone; it's almost always better to include new capabilities/functions in the same patch as the user. Since the only user is the networking bits, it might make more sense to fold this patch into that one.

> diff --git a/include/linux/audit.h b/include/linux/audit.h > index 4f514ed..1f340ad 100644 > --- a/include/linux/audit.h > +++ b/include/linux/audit.h > @@ -234,7 +234,9 @@ struct audit_task_info { > extern struct audit_task_info init_struct_audit; > extern void __init audit_task_init(void); > extern int audit_alloc(struct task_struct *task); > +extern struct audit_context *audit_alloc_local(gfp_t gfpflags); > extern void audit_free(struct task_struct *task); > +extern void audit_free_context(struct audit_context *context); > extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1, > unsigned long a2, unsigned long a3); > extern void __audit_syscall_exit(int ret_success, long ret_value); > @@ -495,6 +497,12 @@ static inline int audit_alloc(struct task_struct *task) > { > return 0; > } > +static inline struct audit_context *audit_alloc_local(gfp_t gfpflags) > +{ > + return NULL; > +} > +static inline void audit_free_context(struct audit_context *context) > +{ } > static inline void audit_free(struct task_struct *task) > { } > static inline void audit_syscall_entry(int major, unsigned long a0, > diff --git a/kernel/audit.h b/kernel/audit.h > index 1cf1c35..a6d00a5 100644 > --- a/kernel/audit.h > +++ b/kernel/audit.h > @@ -110,6 +110,7 @@ struct audit_proctitle { > struct audit_context { > int dummy; /* must be the first element */ > int in_syscall; /* 1 if task is in a syscall */ > + bool local; /* local context needed */ > enum audit_state state, current_state; > unsigned int serial; /* serial number for record */ > int major; /* syscall number */ > diff --git a/kernel/auditsc.c b/kernel/auditsc.c > index cdb24cf..7627f21 100644 > --- a/kernel/auditsc.c > +++ b/kernel/auditsc.c > @@ -913,11 +913,13 @@ static inline void audit_free_aux(struct audit_context *context) > } > } > > -static inline struct audit_context *audit_alloc_context(enum audit_state state) > +static inline struct audit_context *audit_alloc_context(enum audit_state state, > + gfp_t gfpflags) > { > struct audit_context *context; > > - context = kzalloc(sizeof(*context), GFP_KERNEL); > + /* We can be called in atomic context via audit_tg() */ > + context = kzalloc(sizeof(*context), gfpflags); > if (!context) > return NULL; > context->state = state; > @@ -970,7 +972,8 @@ int audit_alloc(struct task_struct *tsk) > return 0; > } > > - if (!(context = audit_alloc_context(state))) { > + context = audit_alloc_context(state, GFP_KERNEL); > + if (!(context)) { > tsk->audit = NULL; > kmem_cache_free(audit_task_cache, info); > kfree(key); > @@ -991,8 +994,27 @@ struct audit_task_info init_struct_audit = { > .ctx = NULL, > }; > > -static inline void audit_free_context(struct audit_context *context) > +struct audit_context *audit_alloc_local(gfp_t gfpflags) > { > + struct audit_context *context; > + > + if (!audit_ever_enabled) > + return NULL; /* Return if not auditing. */ > + > + context = audit_alloc_context(AUDIT_RECORD_CONTEXT, gfpflags); > + if (!context) > + return NULL; > + context->serial = audit_serial(); > + context->ctime = current_kernel_time64(); > + context->local = true; > + return context; > +} > +EXPORT_SYMBOL(audit_alloc_local); > + > +void audit_free_context(struct audit_context *context) > +{ > + if (!context) > + return; > audit_free_names(context); > unroll_tree_refs(context, NULL, 0); > free_tree_refs(context); > @@ -1002,6 +1024,7 @@ static inline void audit_free_context(struct audit_context *context) > audit_proctitle_free(context); > kfree(context); > } > +EXPORT_SYMBOL(audit_free_context); > > static int audit_log_pid_context(struct audit_context *context, pid_t pid, > kuid_t auid, kuid_t uid, unsigned int sessionid, > @@ -2024,7 +2047,7 @@ void __audit_inode_child(struct inode *parent, > int auditsc_get_stamp(struct audit_context *ctx, > struct timespec64 *t, unsigned int *serial) > { > - if (!ctx->in_syscall) > + if (!ctx->in_syscall && !ctx->local) > return 0; > if (!ctx->serial) > ctx->serial = audit_serial(); -- paul moore www.paul-moore.com