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From: David Miller <davem@davemloft.net>
To: rick.p.edgecombe@intel.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	sparclinux@vger.kernel.org, linux-mm@kvack.org,
	netdev@vger.kernel.org, luto@kernel.org, dave.hansen@intel.com,
	namit@vmware.com
Subject: Re: [PATCH v5 0/2] Fix issues with vmalloc flush flag
Date: Tue, 28 May 2019 17:23:27 -0700 (PDT)	[thread overview]
Message-ID: <20190528.172327.2113097810388476996.davem@davemloft.net> (raw)
In-Reply-To: <20190527211058.2729-1-rick.p.edgecombe@intel.com>

From: Rick Edgecombe <rick.p.edgecombe@intel.com>
Date: Mon, 27 May 2019 14:10:56 -0700

> These two patches address issues with the recently added
> VM_FLUSH_RESET_PERMS vmalloc flag.
> 
> Patch 1 addresses an issue that could cause a crash after other
> architectures besides x86 rely on this path.
> 
> Patch 2 addresses an issue where in a rare case strange arguments
> could be provided to flush_tlb_kernel_range(). 

It just occurred to me another situation that would cause trouble on
sparc64, and that's if someone the address range of the main kernel
image ended up being passed to flush_tlb_kernel_range().

That would flush the locked kernel mapping and crash the kernel
instantly in a completely non-recoverable way.

WARNING: multiple messages have this Message-ID (diff)
From: David Miller <davem@davemloft.net>
To: rick.p.edgecombe@intel.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	sparclinux@vger.kernel.org, linux-mm@kvack.org,
	netdev@vger.kernel.org, luto@kernel.org, dave.hansen@intel.com,
	namit@vmware.com
Subject: Re: [PATCH v5 0/2] Fix issues with vmalloc flush flag
Date: Wed, 29 May 2019 00:23:27 +0000	[thread overview]
Message-ID: <20190528.172327.2113097810388476996.davem@davemloft.net> (raw)
In-Reply-To: <20190527211058.2729-1-rick.p.edgecombe@intel.com>

From: Rick Edgecombe <rick.p.edgecombe@intel.com>
Date: Mon, 27 May 2019 14:10:56 -0700

> These two patches address issues with the recently added
> VM_FLUSH_RESET_PERMS vmalloc flag.
> 
> Patch 1 addresses an issue that could cause a crash after other
> architectures besides x86 rely on this path.
> 
> Patch 2 addresses an issue where in a rare case strange arguments
> could be provided to flush_tlb_kernel_range(). 

It just occurred to me another situation that would cause trouble on
sparc64, and that's if someone the address range of the main kernel
image ended up being passed to flush_tlb_kernel_range().

That would flush the locked kernel mapping and crash the kernel
instantly in a completely non-recoverable way.

  parent reply	other threads:[~2019-05-29  0:23 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-27 21:10 [PATCH v5 0/2] Fix issues with vmalloc flush flag Rick Edgecombe
2019-05-27 21:10 ` Rick Edgecombe
2019-05-27 21:10 ` [PATCH v5 1/2] vmalloc: Fix calculation of direct map addr range Rick Edgecombe
2019-05-27 21:10   ` Rick Edgecombe
2019-06-03 12:59   ` [tip:x86/urgent] mm/vmalloc: " tip-bot for Rick Edgecombe
2019-05-27 21:10 ` [PATCH v5 2/2] vmalloc: Avoid rare case of flushing tlb with weird arguments Rick Edgecombe
2019-05-27 21:10   ` Rick Edgecombe
2019-06-03 12:59   ` [tip:x86/urgent] mm/vmalloc: Avoid rare case of flushing TLB " tip-bot for Rick Edgecombe
2019-05-28  8:01 ` [PATCH v5 0/2] Fix issues with vmalloc flush flag Peter Zijlstra
2019-05-28  8:01   ` Peter Zijlstra
2019-05-29  0:23 ` David Miller [this message]
2019-05-29  0:23   ` David Miller
2019-05-29  5:11   ` Edgecombe, Rick P
2019-05-29  5:11     ` Edgecombe, Rick P

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