From: Willy Tarreau <w@1wt.eu>
To: Eric Biggers <ebiggers3@gmail.com>
Cc: linux-fsdevel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Joe Lawrence <joe.lawrence@redhat.com>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Mikulas Patocka <mpatocka@redhat.com>,
"Luis R . Rodriguez" <mcgrof@kernel.org>,
Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org, Eric Biggers <ebiggers@google.com>
Subject: Re: [PATCH 4/7] pipe: fix off-by-one error when checking buffer limits
Date: Mon, 8 Jan 2018 07:42:00 +0100 [thread overview]
Message-ID: <20180108064200.GB10411@1wt.eu> (raw)
In-Reply-To: <20180108053542.6472-5-ebiggers3@gmail.com>
On Sun, Jan 07, 2018 at 09:35:39PM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> With pipe-user-pages-hard set to 'N', users were actually only allowed
> up to 'N - 1' buffers; and likewise for pipe-user-pages-soft.
>
> Fix this to allow up to 'N' buffers, as would be expected.
Interesting. I was a bit surprized at first and found that this was
changed by b0b91d1 ("pipe: fix limit checking in pipe_set_size()").
Prior to this fix, only already allocated pipes were counted. After
the fix, an allocation attempt was made before checking the size. So
I think that your fix is needed in stable versions which backported
the commit above.
> Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Thanks,
Willy
next prev parent reply other threads:[~2018-01-08 6:42 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 5:35 [PATCH 0/7] pipe: buffer limits fixes and cleanups Eric Biggers
2018-01-08 5:35 ` [PATCH 1/7] pipe, sysctl: drop 'min' parameter from pipe-max-size converter Eric Biggers
2018-01-09 22:20 ` Kees Cook
2018-01-10 2:29 ` Eric Biggers
2018-01-10 17:30 ` Kees Cook
2018-01-08 5:35 ` [PATCH 2/7] pipe, sysctl: remove pipe_proc_fn() Eric Biggers
2018-01-08 5:35 ` [PATCH 3/7] pipe: actually allow root to exceed the pipe buffer limits Eric Biggers
2018-01-09 22:23 ` Kees Cook
2018-01-10 2:34 ` Eric Biggers
2018-01-08 5:35 ` [PATCH 4/7] pipe: fix off-by-one error when checking " Eric Biggers
2018-01-08 6:42 ` Willy Tarreau [this message]
2018-01-08 5:35 ` [PATCH 5/7] pipe: reject F_SETPIPE_SZ with size over UINT_MAX Eric Biggers
2018-01-09 22:24 ` Kees Cook
2018-01-08 5:35 ` [PATCH 6/7] pipe: simplify round_pipe_size() Eric Biggers
2018-01-09 22:27 ` Kees Cook
2018-01-10 2:52 ` Eric Biggers
2018-01-10 3:13 ` Kees Cook
2018-01-08 5:35 ` [PATCH 7/7] pipe: read buffer limits atomically Eric Biggers
2018-01-09 22:27 ` Kees Cook
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