Re: [PATCH v24 21/25] audit: add support for non-syscall auxiliary records

On 1/26/2021 10:42 AM, Richard Guy Briggs wrote: > On 2021-01-26 08:41, Casey Schaufler 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; >> Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; >> Cc: linux-audit(a)redhat.com >> To: Richard Guy Briggs <rgb(a)redhat.com&gt; > This has been minorly bothering me for several revisions... Is there a > way for the development/authorship to be accurately reflected > if/when this patch is merged before the contid patch set? I don't know the right way to do that because I had to pull some of what was in the original patch out. Any way you would like it done is fine with me.

>> --- >> include/linux/audit.h | 8 ++++++++ >> kernel/audit.h | 1 + >> kernel/auditsc.c | 33 ++++++++++++++++++++++++++++----- >> 3 files changed, 37 insertions(+), 5 deletions(-) >> >> diff --git a/include/linux/audit.h b/include/linux/audit.h >> index 418a485af114..97cd7471e572 100644 >> --- a/include/linux/audit.h >> +++ b/include/linux/audit.h >> @@ -289,6 +289,8 @@ static inline int audit_signal_info(int sig, struct task_struct *t) >> /* Public API */ >> extern int audit_alloc(struct task_struct *task); >> extern void __audit_free(struct task_struct *task); >> +extern struct audit_context *audit_alloc_local(gfp_t gfpflags); >> +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); >> @@ -552,6 +554,12 @@ static inline void audit_log_nfcfg(const char *name, u8 af, >> extern int audit_n_rules; >> extern int audit_signals; >> #else /* CONFIG_AUDITSYSCALL */ >> ++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 int audit_alloc(struct task_struct *task) >> { >> return 0; >> diff --git a/kernel/audit.h b/kernel/audit.h >> index ce41886807bb..3f2285e1c6e0 100644 >> --- a/kernel/audit.h >> +++ b/kernel/audit.h >> @@ -99,6 +99,7 @@ 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 de2b2ecb3aea..479b3933d788 100644 >> --- a/kernel/auditsc.c >> +++ b/kernel/auditsc.c >> @@ -927,11 +927,13 @@ 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; >> @@ -967,7 +969,8 @@ int audit_alloc(struct task_struct *tsk) >> return 0; >> } >> >> - if (!(context = audit_alloc_context(state))) { >> + context = audit_alloc_context(state, GFP_KERNEL); >> + if (!context) { >> kfree(key); >> audit_log_lost("out of memory in audit_alloc"); >> return -ENOMEM; >> @@ -979,8 +982,27 @@ int audit_alloc(struct task_struct *tsk) >> return 0; >> } >> >> -static inline void audit_free_context(struct audit_context *context) >> +struct audit_context *audit_alloc_local(gfp_t gfpflags) >> { >> + struct audit_context *context = NULL; >> + >> + context = audit_alloc_context(AUDIT_RECORD_CONTEXT, gfpflags); >> + if (!context) { >> + audit_log_lost("out of memory in audit_alloc_local"); >> + goto out; >> + } >> + context->serial = audit_serial(); >> + ktime_get_coarse_real_ts64(&context->ctime); >> + context->local = true; >> +out: >> + return context; >> +} >> +EXPORT_SYMBOL(audit_alloc_local); >> + >> +void audit_free_context(struct audit_context *context) >> +{ >> + if (!context) >> + return; >> audit_free_module(context); >> audit_free_names(context); >> unroll_tree_refs(context, NULL, 0); >> @@ -991,6 +1013,7 @@ 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, >> @@ -2214,7 +2237,7 @@ EXPORT_SYMBOL_GPL(__audit_inode_child); >> 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(); >> -- >> 2.25.4 >> > - RGB