Return-Path: Message-ID: <54C8CC7C.6080005@huawei.com> Date: Wed, 28 Jan 2015 19:48:12 +0800 From: Zefan Li MIME-Version: 1.0 To: Nadav Amit CC: , , LKML , Nadav Amit , "Paolo Bonzini" Subject: Re: [PATCH 3.4 152/177] KVM: x86: Fix uninitialized op->type for some immediate values References: <1422418050-12581-1-git-send-email-lizf@kernel.org> <1422418236-12852-243-git-send-email-lizf@kernel.org> <861C01D3-25A0-4411-9FBF-C72128CF3EBC@gmail.com> In-Reply-To: <861C01D3-25A0-4411-9FBF-C72128CF3EBC@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 2015/1/28 16:47, Nadav Amit wrote: > This bug should have no effect on Linux 3.4. It shouldn’t hurt, but the > problem it fixes was introduced in 3.16 or 3.17. Dropped. Thanks! > > Nadav > > lizf@kernel.org wrote: > >> From: Nadav Amit >> >> 3.4.106-rc1 review patch. If anyone has any objections, please let me know. >> >> ------------------ >> >> >> commit d29b9d7ed76c0b961603ca692b8a562556a20212 upstream. >> >> The emulator could reuse an op->type from a previous instruction for some >> immediate values. If it mistakenly considers the operands as memory >> operands, it will performs a memory read and overwrite op->val. >> >> Consider for instance the ROR instruction - src2 (the number of times) >> would be read from memory instead of being used as immediate. >> >> Mark every immediate operand as such to avoid this problem. >> >> Fixes: c44b4c6ab80eef3a9c52c7b3f0c632942e6489aa >> Signed-off-by: Nadav Amit >> Signed-off-by: Paolo Bonzini >> Signed-off-by: Zefan Li