From: Thomas Gleixner <tglx@linutronix.de>
To: Greg KH <gregkh@linuxfoundation.org>,
syzbot <syzbot+353be47c9ce21b68b7ed@syzkaller.appspotmail.com>,
bp@alien8.de, dave.hansen@linux.intel.com,
dmitry.torokhov@gmail.com, ebiederm@xmission.com, hpa@zytor.com,
jeremy.linton@arm.com, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, luto@kernel.org, mingo@redhat.com,
peterz@infradead.org, stern@rowland.harvard.edu,
syzkaller-bugs@googlegroups.com, x86@kernel.org
Subject: Re: WARNING in memtype_reserve
Date: Sat, 09 May 2020 12:00:57 +0200 [thread overview]
Message-ID: <87wo5l4ecm.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20200509074507.GC1831917@kroah.com>
Greg KH <gregkh@linuxfoundation.org> writes:
> On Sat, May 09, 2020 at 12:20:14AM -0700, syzbot wrote:
>> memtype_reserve failed: [mem 0xffffffffff000-0x00008fff], req write-back
>> WARNING: CPU: 1 PID: 7025 at arch/x86/mm/pat/memtype.c:589 memtype_reserve+0x69f/0x820 arch/x86/mm/pat/memtype.c:589
>
> So should memtype_reserve() not do a WARN if given invalid parameters as
> it can be triggered by userspace requests?
>
> A normal "invalid request" debug line is probably all that is needed,
> right?
I disagree. The callsite espcially if user space triggerable should not
attempt to ask for a reservation where start > end:
>> memtype_reserve failed: [mem 0xffffffffff000-0x00008fff], req write-back
The real question is which part of the call chain is responsible for
this. That needs to be fixed.
Thanks,
tglx
next prev parent reply other threads:[~2020-05-09 10:01 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-09 7:20 WARNING in memtype_reserve syzbot
2020-05-09 7:45 ` Greg KH
2020-05-09 10:00 ` Thomas Gleixner [this message]
2020-05-09 13:41 ` Alan Stern
2020-05-13 16:21 ` Thomas Gleixner
2020-05-13 12:44 ` Greg KH
2020-05-13 16:22 ` Thomas Gleixner
2020-05-13 16:55 ` Greg KH
[not found] ` <20200514035458.14760-1-hdanton@sina.com>
2020-05-14 6:14 ` Christoph Hellwig
2020-05-14 6:19 ` Dmitry Vyukov
2020-05-14 6:27 ` Validating dma_mmap_coherent() parameters before calling (was Re: WARNING in memtype_reserve) Greg KH
2020-05-14 6:31 ` Christoph Hellwig
2020-05-14 7:46 ` Greg KH
2020-05-14 11:17 ` Jeremy Linton
2020-05-14 11:22 ` Greg KH
2020-05-14 11:10 ` Jeremy Linton
2020-05-14 11:14 ` Christoph Hellwig
2020-05-14 11:16 ` Jeremy Linton
2020-05-14 9:08 ` WARNING in memtype_reserve syzbot
2020-05-09 17:42 ` Jeremy Linton
[not found] ` <20200509154728.1548-1-hdanton@sina.com>
2020-05-13 12:41 ` Greg KH
2020-05-14 9:20 ` Greg KH
2020-05-14 10:44 ` syzbot
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