[PATCH 5.17 051/158] audit,io_uring,io-wq: call __audit_uring_exit for dummy contexts

Greg Kroah-Hartman
2022-05-23T17:54:47Z

From: Julian Orth <ju.orth@gmail.com>

commit 69e9cd66ae1392437234a63a3a1d60b6655f92ef upstream.

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

Cc: stable@vger.kernel.org
Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Signed-off-by: Julian Orth <ju.orth@gmail.com>
[PM: subject line tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/audit.h | 2 +-
kernel/auditsc.c | 6 ++++++
2 files changed, 7 insertions(+), 1 deletion(-)

--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -339,7 +339,7 @@ static inline void audit_uring_entry(u8
}
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,
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1959,6 +1959,12 @@ void __audit_uring_exit(int success, lon
{
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