Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Julian Orth <ju.orth@gmail.com>
To:     Paul Moore <paul@paul-moore.com>, Eric Paris <eparis@redhat.com>
Cc:     ju.orth@gmail.com, linux-audit@redhat.com,
        linux-kernel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 1/1] audit,io_uring,io-wq: call __audit_uring_exit for dummy contexts
Date:   Tue, 17 May 2022 12:32:53 +0200
Message-Id: <20220517103253.22601-2-ju.orth@gmail.com>
In-Reply-To: <20220517103253.22601-1-ju.orth@gmail.com>
References: <20220517103253.22601-1-ju.orth@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Not calling the function for dummy contexts will cause the context to
not be reset. During the next syscall, this will cause an error in
__audit_syscall_entry:

	WARN_ON(context->context != AUDIT_CTX_UNUSED);
	WARN_ON(context->name_count);
	if (context->context != AUDIT_CTX_UNUSED || context->name_count) {
		audit_panic("unrecoverable error in audit_syscall_entry()");
		return;
	}

These problematic dummy contexts are created via the following call
chain:

       exit_to_user_mode_prepare
    -> arch_do_signal_or_restart
    -> get_signal
    -> task_work_run
    -> tctx_task_work
    -> io_req_task_submit
    -> io_issue_sqe
    -> audit_uring_entry

Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Signed-off-by: Julian Orth <ju.orth@gmail.com>
---
 include/linux/audit.h | 2 +-
 kernel/auditsc.c      | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index d06134ac6245..cece70231138 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -339,7 +339,7 @@ static inline void audit_uring_entry(u8 op)
 }
 static inline void audit_uring_exit(int success, long code)
 {
-	if (unlikely(!audit_dummy_context()))
+	if (unlikely(audit_context()))
 		__audit_uring_exit(success, code);
 }
 static inline void audit_syscall_entry(int major, unsigned long a0,
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ea2ee1181921..f3a2abd6d1a1 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1959,6 +1959,12 @@ void __audit_uring_exit(int success, long code)
 {
 	struct audit_context *ctx = audit_context();
 
+	if (ctx->dummy) {
+		if (ctx->context != AUDIT_CTX_URING)
+			return;
+		goto out;
+	}
+
 	if (ctx->context == AUDIT_CTX_SYSCALL) {
 		/*
 		 * NOTE: See the note in __audit_uring_entry() about the case
-- 
2.36.1