From: Dan Clash <[email protected]>
To: Paul Moore <[email protected]>, Jens Axboe <[email protected]>
Cc: "[email protected]" <[email protected]>,
"[email protected]" <[email protected]>,
"[email protected]" <[email protected]>,
"[email protected]" <[email protected]>
Subject: Re: [EXTERNAL] Re: audit: io_uring openat triggers audit reference count underflow in worker thread
Date: Mon, 9 Oct 2023 02:38:43 +0000 [thread overview]
Message-ID: <MW2PR2101MB1033E52DD9307F9EF15F1E85F1CEA@MW2PR2101MB1033.namprd21.prod.outlook.com> (raw)
In-Reply-To: <CAHC9VhQ0z4wuH7R=KRcUTyZuRs7adYTiH5JjohJSz4d2-Jd9EQ@mail.gmail.com>
I retested with the following change as a sanity check:
- BUG_ON(name->refcnt <= 0);
+ BUG_ON(atomic_read(&name->refcnt) <= 0);
checkpatch.pl suggests using WARN_ON_ONCE rather than BUG.
devvm ~ $ ~/linux/scripts/checkpatch.pl --patch ~/io_uring_audit_hang_atomic.patch
WARNING: Do not crash the kernel unless it is absolutely unavoidable
--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants
#28: FILE: fs/namei.c:262:
+ BUG_ON(atomic_read(&name->refcnt) <= 0);
...
refcount_t uses WARN_ON_ONCE.
I can think of three choices:
1. Use atomic_t and remove the BUG line.
2. Use refcount_t and remove the BUG line.
3. Use atomic_t and partially implement the warn behavior of refcount_t.
Choice 1 and 2 seem better than choice 3.
next prev parent reply other threads:[~2023-10-09 2:38 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-06 20:09 audit: io_uring openat triggers audit reference count underflow in worker thread Dan Clash
2023-10-07 2:32 ` Jens Axboe
2023-10-07 13:11 ` Jens Axboe
2023-10-07 15:13 ` Paul Moore
2023-10-09 2:38 ` Dan Clash [this message]
2023-10-09 13:40 ` [EXTERNAL] " Jens Axboe
2023-10-12 21:12 ` Dan Clash
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