GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

audit: add filtering for io_uring records

Browse source 
This patch adds basic audit io_uring filtering, using as much of the
existing audit filtering infrastructure as possible.  In order to do
this we reuse the audit filter rule's syscall mask for the io_uring
operation and we create a new filter for io_uring operations as
AUDIT_FILTER_URING_EXIT/audit_filter_list[7].

Thanks to Richard Guy Briggs for his review, feedback, and work on
the corresponding audit userspace changes.

Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Paul Moore 2021-04-18 21:54:47 -04:00
parent 5bd2182d58
commit 67daf270ce
5 changed files with 64 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

60
kernel/auditsc.c
View file

@ -805,6 +805,34 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
return rule->mask[word] & bit;
}
/**
* audit_filter_uring - apply filters to an io_uring operation
* @tsk: associated task
* @ctx: audit context
*/
static void audit_filter_uring(struct task_struct *tsk,
struct audit_context *ctx)
{
struct audit_entry *e;
enum audit_state state;
if (auditd_test_task(tsk))
return;
rcu_read_lock();
list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_URING_EXIT],
list) {
if (audit_in_mask(&e->rule, ctx->uring_op) &&
audit_filter_rules(tsk, &e->rule, ctx, NULL, &state,
false)) {
rcu_read_unlock();
ctx->current_state = state;
return;
}
}
rcu_read_unlock();
}
/* At syscall exit time, this filter is called if the audit_state is
* not low enough that auditing cannot take place, but is also not
* high enough that we already know we have to write an audit record
@ -1757,7 +1785,7 @@ static void audit_log_exit(void)
* __audit_free - free a per-task audit context
* @tsk: task whose audit context block to free
*
* Called from copy_process and do_exit
* Called from copy_process, do_exit, and the io_uring code
*/
void __audit_free(struct task_struct *tsk)
{
@ -1775,15 +1803,21 @@ void __audit_free(struct task_struct *tsk)
* random task_struct that doesn't doesn't have any meaningful data we
* need to log via audit_log_exit().
*/
if (tsk == current && !context->dummy &&
context->context == AUDIT_CTX_SYSCALL) {
if (tsk == current && !context->dummy) {
context->return_valid = AUDITSC_INVALID;
context->return_code = 0;
audit_filter_syscall(tsk, context);
audit_filter_inodes(tsk, context);
if (context->current_state == AUDIT_STATE_RECORD)
audit_log_exit();
if (context->context == AUDIT_CTX_SYSCALL) {
audit_filter_syscall(tsk, context);
audit_filter_inodes(tsk, context);
if (context->current_state == AUDIT_STATE_RECORD)
audit_log_exit();
} else if (context->context == AUDIT_CTX_URING) {
/* TODO: verify this case is real and valid */
audit_filter_uring(tsk, context);
audit_filter_inodes(tsk, context);
if (context->current_state == AUDIT_STATE_RECORD)
audit_log_uring(context);
}
}
audit_set_context(tsk, NULL);
@ -1867,12 +1901,6 @@ void __audit_uring_exit(int success, long code)
{
struct audit_context *ctx = audit_context();
/*
* TODO: At some point we will likely want to filter on io_uring ops
* and other things similar to what we do for syscalls, but that
* is something for another day; just record what we can here.
*/
if (ctx->context == AUDIT_CTX_SYSCALL) {
/*
* NOTE: See the note in __audit_uring_entry() about the case
@ -1895,6 +1923,8 @@ void __audit_uring_exit(int success, long code)
* the behavior here.
*/
audit_filter_syscall(current, ctx);
if (ctx->current_state != AUDIT_STATE_RECORD)
audit_filter_uring(current, ctx);
audit_filter_inodes(current, ctx);
if (ctx->current_state != AUDIT_STATE_RECORD)
return;
@ -1907,6 +1937,8 @@ void __audit_uring_exit(int success, long code)
if (!list_empty(&ctx->killed_trees))
audit_kill_trees(ctx);
/* run through both filters to ensure we set the filterkey properly */
audit_filter_uring(current, ctx);
audit_filter_inodes(current, ctx);
if (ctx->current_state != AUDIT_STATE_RECORD)
goto out;