public inbox for [email protected]
 help / color / mirror / Atom feed
* [PATCH] io_uring: don't audit the capability check in io_uring_create()
@ 2023-07-18 11:56 Ondrej Mosnacek
  2023-07-18 13:30 ` Jeff Moyer
  2023-07-18 20:16 ` Jens Axboe
  0 siblings, 2 replies; 4+ messages in thread
From: Ondrej Mosnacek @ 2023-07-18 11:56 UTC (permalink / raw)
  To: Jens Axboe
  Cc: Pavel Begunkov, io-uring, linux-security-module, selinux,
	linux-kernel

The check being unconditional may lead to unwanted denials reported by
LSMs when a process has the capability granted by DAC, but denied by an
LSM. In the case of SELinux such denials are a problem, since they can't
be effectively filtered out via the policy and when not silenced, they
produce noise that may hide a true problem or an attack.

Since not having the capability merely means that the created io_uring
context will be accounted against the current user's RLIMIT_MEMLOCK
limit, we can disable auditing of denials for this check by using
ns_capable_noaudit() instead of capable().

Fixes: 2b188cc1bb85 ("Add io_uring IO interface")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2193317
Signed-off-by: Ondrej Mosnacek <[email protected]>
---
 io_uring/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 7505de2428e03..a9923676d16d6 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3870,7 +3870,7 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
 		ctx->syscall_iopoll = 1;
 
 	ctx->compat = in_compat_syscall();
-	if (!capable(CAP_IPC_LOCK))
+	if (!ns_capable_noaudit(&init_user_ns, CAP_IPC_LOCK))
 		ctx->user = get_uid(current_user());
 
 	/*
-- 
2.41.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-07-25 11:10 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-07-18 11:56 [PATCH] io_uring: don't audit the capability check in io_uring_create() Ondrej Mosnacek
2023-07-18 13:30 ` Jeff Moyer
2023-07-25 11:07   ` Ondrej Mosnacek
2023-07-18 20:16 ` Jens Axboe

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox