linux-kernel - RE: [PATCH 2/3] x86/mce: Avoid infinite loop for copy from user recovery

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 31 Jul 2021 20:43:13 +0000
From:   "Luck, Tony" <tony.luck@...el.com>
To:     Jue Wang <juew@...gle.com>
CC:     Borislav Petkov <bp@...en8.de>,
        "dinghui@...gfor.com.cn" <dinghui@...gfor.com.cn>,
        "huangcun@...gfor.com.cn" <huangcun@...gfor.com.cn>,
        "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        HORIGUCHI NAOYA(堀口 直也) 
        <naoya.horiguchi@....com>, Oscar Salvador <osalvador@...e.de>,
        x86 <x86@...nel.org>, "Song, Youquan" <youquan.song@...el.com>
Subject: RE: [PATCH 2/3] x86/mce: Avoid infinite loop for copy from user
 recovery

> After cherry picking patch 1 & 2, I saw the following with 2 UC errors injected
> into the user space buffer passed into write(2), as expected:
>
> [  287.994754] Kernel panic - not syncing: Machine checks to different
> user pages

Interesting.  What are the offsets of the two injected errors in your test (both
w.r.t. the start of the buffer, and within a page).

> The kernel tested with has its x86/mce and mm/memory-failure aligned with
> upstream till around 2020/11.
>
> Is there any other patch that I have missed to the write syscall etc?

There is a long series of patches from Al Viro to lib/iov_iter.c that are maybe
also relevent in making the kernel copy from user stop at the first poison
address in the buffer.

-Tony