Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1742688 > unrolled thread

Re: [v1] iov_iter: fix page_copy_sane for compound pages

Started byThiago Macieira <thiago.macieira@intel.com>
First post2017-09-30 22:20 +0200
Last post2017-09-30 23:00 +0200
Articles 2 — 2 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.


Contents

  Re: [v1] iov_iter: fix page_copy_sane for compound pages Thiago Macieira <thiago.macieira@intel.com> - 2017-09-30 22:20 +0200
    Re: [v1] iov_iter: fix page_copy_sane for compound pages Eric Dumazet <edumazet@google.com> - 2017-09-30 23:00 +0200

#1742688 — Re: [v1] iov_iter: fix page_copy_sane for compound pages

FromThiago Macieira <thiago.macieira@intel.com>
Date2017-09-30 22:20 +0200
SubjectRe: [v1] iov_iter: fix page_copy_sane for compound pages
Message-ID<uvwoV-uH-3@gated-at.bofh.it>
On Tuesday, 29 August 2017 11:20:32 PDT Petar Penkov wrote:
> Issue is that if the data crosses a page boundary inside a compound
> page, this check will incorrectly trigger a WARN_ON.
> 
> To fix this, compute the order using the head of the compound page and
> adjust the offset to be relative to that head.
> 
> Fixes: 72e809ed81ed ("iov_iter: sanity checks for copy to/from page
> primitives")

Hello

Is this patch slated to end up in one of the 4.13.x updates? It landed on 
v4.14-rc2 already but seems to have missed the 4.13.3 and 4.13.4 tagging.

Without this patch, I can't connect any USB Ethernet or the kernel will start 
producing that WARN_ON message and returning -EFAULT for quite a few programs.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel Open Source Technology Center

[toc] | [next] | [standalone]


#1742698

FromEric Dumazet <edumazet@google.com>
Date2017-09-30 23:00 +0200
Message-ID<uvx1D-JN-1@gated-at.bofh.it>
In reply to#1742688
On Sat, Sep 30, 2017 at 12:24 PM, Thiago Macieira
<thiago.macieira@intel.com> wrote:
> On Tuesday, 29 August 2017 11:20:32 PDT Petar Penkov wrote:
>> Issue is that if the data crosses a page boundary inside a compound
>> page, this check will incorrectly trigger a WARN_ON.
>>
>> To fix this, compute the order using the head of the compound page and
>> adjust the offset to be relative to that head.
>>
>> Fixes: 72e809ed81ed ("iov_iter: sanity checks for copy to/from page
>> primitives")
>
> Hello
>
> Is this patch slated to end up in one of the 4.13.x updates? It landed on
> v4.14-rc2 already but seems to have missed the 4.13.3 and 4.13.4 tagging.
>
> Without this patch, I can't connect any USB Ethernet or the kernel will start
> producing that WARN_ON message and returning -EFAULT for quite a few programs.
>

Hmm... problem Petar had originally has been solved.

His commit ( 90e33d45940793def6f773b2d528e9f3c84ffdc7 in Dave Miller net-next)
no longer hits the problem, while his prior version triggered the issue.

Relevant and updated part is :

+               page = virt_to_head_page(data);
+               offset = data - page_address(page);
+               skb_fill_page_desc(skb, i - 1, page, offset, fragsz);

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web