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 <[email protected]>
---
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
On Tue, May 17, 2022 at 6:33 AM Julian Orth <[email protected]> wrote:
>
> 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 <[email protected]>
> ---
> include/linux/audit.h | 2 +-
> kernel/auditsc.c | 6 ++++++
> 2 files changed, 7 insertions(+), 1 deletion(-)
Hi Julian,
Thanks for the report and the patch too! I agree that it does seem a
little odd that we haven't seen this before, let me dig into this a
bit more today and respond back.
--
paul-moore.com
On Tue, May 17, 2022 at 9:12 AM Paul Moore <[email protected]> wrote:
> On Tue, May 17, 2022 at 6:33 AM Julian Orth <[email protected]> wrote:
> >
> > 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 <[email protected]>
> > ---
> > include/linux/audit.h | 2 +-
> > kernel/auditsc.c | 6 ++++++
> > 2 files changed, 7 insertions(+), 1 deletion(-)
>
> Hi Julian,
>
> Thanks for the report and the patch too! I agree that it does seem a
> little odd that we haven't seen this before, let me dig into this a
> bit more today and respond back.
The patch looks good to me, thanks again. I just merged this into the
audit/stable-5.18 branch and added a stable tag; assuming the test
runs go okay I'll send this up to Linus tomorrow.
--
paul-moore.com