From: Linus Torvalds <torvalds@linux-foundation.org>
To: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.cz>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.org>,
raven@themaw.net, Christian Brauner <christian@brauner.io>,
keyrings@vger.kernel.org, linux-usb@vger.kernel.org,
linux-block <linux-block@vger.kernel.org>,
LSM List <linux-security-module@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [GIT PULL] pipe: Notification queue preparation
Date: Thu, 5 Dec 2019 09:24:51 -0800 [thread overview]
Message-ID: <CAHk-=wi_on1EAbVi1Q01i7=0_GL=nKmz6s9677YZf74H8=Sw0g@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wgwwJ+ZEtycujFdNmpS8TjwCYyT+oHfV7d-GekyaX91xg@mail.gmail.com>
On Thu, Dec 5, 2019 at 9:12 AM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> It would be interesting to hear if somebody else is waiting on the
> read side too.
Looking once more at that commit, I find at least one bug, but I'm
pretty sure that's not the cause of this problem.
DavidH, watch out for things like this:
- for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
+ for (idx = tail; idx < head && rem < len; idx++)
which is a completely buggy conversion.
You can't compare tail and head with an inequality, it gets the
wraparound case wrong.
But I found only one of those, and it's fuse-specific, plus the
overflow would take a long time to trigger, so I'm pretty sure this
isn't what DavidS is reporting.
Linus
next prev parent reply other threads:[~2019-12-05 17:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-25 22:39 [GIT PULL] pipe: Notification queue preparation David Howells
2019-11-30 23:05 ` pr-tracker-bot
2019-12-05 12:58 ` David Sterba
2019-12-05 13:56 ` David Howells
2019-12-05 17:12 ` Linus Torvalds
2019-12-05 17:24 ` Linus Torvalds [this message]
2019-12-05 17:21 ` David Sterba
2019-12-05 17:33 ` Linus Torvalds
2019-12-05 17:25 ` David Howells
2019-12-05 18:18 ` David Sterba
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