From: Linus Torvalds <[email protected]>
To: Alexey Gladkov <[email protected]>
Cc: LKML <[email protected]>,
io-uring <[email protected]>,
Kernel Hardening <[email protected]>,
Linux Containers <[email protected]>,
Linux-MM <[email protected]>, Alexey Gladkov <[email protected]>,
Andrew Morton <[email protected]>,
Christian Brauner <[email protected]>,
"Eric W . Biederman" <[email protected]>,
Jann Horn <[email protected]>, Jens Axboe <[email protected]>,
Kees Cook <[email protected]>,
Oleg Nesterov <[email protected]>
Subject: Re: [RFC PATCH v3 1/8] Use refcount_t for ucounts reference counting
Date: Mon, 18 Jan 2021 11:14:48 -0800 [thread overview]
Message-ID: <CAHk-=wjsg0Lgf1Mh2UiJE4sqBDDo0VhFVBUbhed47ot2CQQwfQ@mail.gmail.com> (raw)
In-Reply-To: <116c7669744404364651e3b380db2d82bb23f983.1610722473.git.gladkov.alexey@gmail.com>
On Fri, Jan 15, 2021 at 6:59 AM Alexey Gladkov <[email protected]> wrote:
>
> @@ -152,10 +153,7 @@ static struct ucounts *get_ucounts(struct user_namespace *ns, kuid_t uid)
> ucounts = new;
> }
> }
> - if (ucounts->count == INT_MAX)
> - ucounts = NULL;
> - else
> - ucounts->count += 1;
> + refcount_inc(&ucounts->count);
> spin_unlock_irq(&ucounts_lock);
> return ucounts;
> }
This is wrong.
It used to return NULL when the count saturated.
Now it just silently saturates.
I'm not sure how many people care, but that NULL return ends up being
returned quite widely (through "inc_uncount()" and friends).
The fact that this has no commit message at all to explain what it is
doing and why is also a grounds for just NAK.
Linus
next prev parent reply other threads:[~2021-01-18 19:22 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-15 14:57 [RFC PATCH v3 0/8] Count rlimits in each user namespace Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 1/8] Use refcount_t for ucounts reference counting Alexey Gladkov
2021-01-18 19:14 ` Linus Torvalds [this message]
2021-01-18 19:45 ` Alexey Gladkov
2021-01-18 20:34 ` Linus Torvalds
2021-01-18 20:56 ` Alexey Gladkov
2021-01-19 4:35 ` Kaiwan N Billimoria
2021-01-20 1:57 ` Eric W. Biederman
2021-01-20 1:58 ` Eric W. Biederman
2021-01-21 12:04 ` Alexey Gladkov
2021-01-21 15:50 ` Eric W. Biederman
2021-01-21 16:07 ` Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 2/8] Add a reference to ucounts for each cred Alexey Gladkov
2021-01-18 8:31 ` [PATCH v4 " Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 3/8] Move RLIMIT_NPROC counter to ucounts Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 4/8] Move RLIMIT_MSGQUEUE " Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 5/8] Move RLIMIT_SIGPENDING " Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 6/8] Move RLIMIT_MEMLOCK " Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 7/8] Move RLIMIT_NPROC check to the place where we increment the counter Alexey Gladkov
2021-01-15 14:57 ` [RFC PATCH v3 8/8] kselftests: Add test to check for rlimit changes in different user namespaces Alexey Gladkov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAHk-=wjsg0Lgf1Mh2UiJE4sqBDDo0VhFVBUbhed47ot2CQQwfQ@mail.gmail.com' \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox