From: Al Viro <viro@zeniv.linux.org.uk>
To: Tony Luck <tony.luck@intel.com>
Cc: "Borislav Petkov" <bp@alien8.de>, "Jue Wang" <juew@google.com>,
"Ding Hui" <dinghui@sangfor.com.cn>,
"HORIGUCHI NAOYA(堀口 直也)" <naoya.horiguchi@nec.com>,
"Oscar Salvador" <osalvador@suse.de>,
"Youquan Song" <youquan.song@intel.com>,
huangcun@sangfor.com.cn, X86-ML <x86@kernel.org>,
"Linux Edac Mailing List" <linux-edac@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/3] x86/mce: Avoid infinite loop for copy from user recovery
Date: Sat, 21 Aug 2021 21:51:11 +0000 [thread overview]
Message-ID: <YSF1T85pnplkm0Xo@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <CA+8MBb+M5JoDGONxZuMHZb8VU4DmG=zsv_0JuBhnzn6T=eSKEA@mail.gmail.com>
On Fri, Aug 20, 2021 at 09:51:41PM -0700, Tony Luck wrote:
> On Fri, Aug 20, 2021 at 1:25 PM Luck, Tony <tony.luck@intel.com> wrote:
> > Probably the same for the two different addresses case ... though I'm
> > not 100% confident about that. There could be some ioctl() that peeks
> > at two parts of a passed in structure, and the user might pass in a
> > structure that spans across a page boundary with both pages poisoned.
> > But that would only hit if the driver code ignored the failure of the
> > first get_user() and blindly tried the second. So I'd count that as a
> > critically bad driver bug.
>
> Or maybe driver writers are just evil :-(
>
> for (i = 0; i < len; i++) {
> tx_wait(10);
> get_user(dsp56k_host_interface.data.b[1], bin++);
> get_user(dsp56k_host_interface.data.b[2], bin++);
> get_user(dsp56k_host_interface.data.b[3], bin++);
> }
Almost any unchecked get_user()/put_user() is a bug. Fortunately, there's
not a lot of them
<greps>
93 for put_user() and 73 for get_user(). _Some_ of the former variety might
be legitimate, but most should be taken out and shot.
And dsp56k should be taken out and shot, period ;-/ This is far from the
worst in there...
next prev parent reply other threads:[~2021-08-21 21:51 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-06 19:06 [PATCH 0/3] More machine check recovery fixes Tony Luck
2021-07-06 19:06 ` [PATCH 1/3] x86/mce: Change to not send SIGBUS error during copy from user Tony Luck
2021-07-06 19:06 ` [PATCH 2/3] x86/mce: Avoid infinite loop for copy from user recovery Tony Luck
2021-07-06 19:06 ` [PATCH 3/3] x86/mce: Drop copyin special case for #MC Tony Luck
2021-08-18 0:29 ` [PATCH v2 0/3] More machine check recovery fixes Tony Luck
2021-08-18 0:29 ` [PATCH v2 1/3] x86/mce: Avoid infinite loop for copy from user recovery Tony Luck
2021-08-20 17:31 ` Borislav Petkov
2021-08-20 18:59 ` Luck, Tony
2021-08-20 19:27 ` Borislav Petkov
2021-08-20 20:23 ` Luck, Tony
2021-08-21 4:51 ` Tony Luck
2021-08-21 21:51 ` Al Viro [this message]
2021-08-22 14:36 ` Borislav Petkov
2021-08-20 20:33 ` Luck, Tony
2021-08-22 14:46 ` Borislav Petkov
2021-08-23 15:24 ` Luck, Tony
2021-09-13 9:24 ` Borislav Petkov
2021-09-13 21:52 ` [PATCH v3] " Luck, Tony
2021-09-14 8:28 ` Borislav Petkov
2021-08-18 0:29 ` [PATCH v2 2/3] x86/mce: Change to not send SIGBUS error during copy from user Tony Luck
2021-08-18 0:29 ` [PATCH v2 3/3] x86/mce: Drop copyin special case for #MC Tony Luck
2021-09-20 9:13 ` Borislav Petkov
2021-09-20 16:18 ` Luck, Tony
2021-09-20 16:37 ` Borislav Petkov
2021-09-20 16:43 ` Luck, Tony
2021-08-18 16:14 ` [PATCH v2 0/3] More machine check recovery fixes Luck, Tony
-- strict thread matches above, loose matches on Subject: below --
2021-01-08 22:22 [PATCH 0/2] Fix infinite machine check loop in futex_wait_setup() Tony Luck
2021-01-11 21:44 ` [PATCH v2 0/3] " Tony Luck
2021-01-11 21:44 ` [PATCH v2 1/3] x86/mce: Avoid infinite loop for copy from user recovery Tony Luck
2021-01-11 22:11 ` Andy Lutomirski
2021-01-11 22:20 ` Luck, Tony
2021-01-12 17:00 ` Andy Lutomirski
2021-01-12 17:16 ` Luck, Tony
2021-01-12 17:21 ` Andy Lutomirski
2021-01-12 18:23 ` Luck, Tony
2021-01-12 18:57 ` Andy Lutomirski
2021-01-12 20:52 ` Luck, Tony
2021-01-12 22:04 ` Andy Lutomirski
2021-01-13 1:50 ` Luck, Tony
2021-01-13 4:15 ` Andy Lutomirski
2021-01-13 10:00 ` Borislav Petkov
2021-01-13 16:06 ` Luck, Tony
2021-01-13 16:19 ` Borislav Petkov
2021-01-13 16:32 ` Luck, Tony
2021-01-13 17:35 ` Borislav Petkov
2021-01-14 20:22 ` Borislav Petkov
2021-01-14 21:05 ` Luck, Tony
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