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From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Brian Gerst <brgerst@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Borislav Petkov <bp@alien8.de>, Stas Sergeev <stsp@list.ru>,
	Andy Lutomirski <luto@kernel.org>
Subject: [PATCH urgent 2/2] x86/vm86: Set thread.vm86 to NULL on fork/clone
Date: Fri, 30 Oct 2015 22:42:46 -0700
Message-ID: <71c5d6985d70ec8197c8d72f003823c81b7dcf99.1446270067.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1446270067.git.luto@kernel.org>
In-Reply-To: <cover.1446270067.git.luto@kernel.org>

thread.vm86 points to per-task information -- the pointer should not
be copied on clone.

Fixes: d4ce0f26c790 ("x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/kernel/process.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 2199d9b774c8..b9ac5434e176 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -83,6 +83,9 @@ EXPORT_SYMBOL_GPL(idle_notifier_unregister);
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
 	memcpy(dst, src, arch_task_struct_size);
+#ifdef CONFIG_VM86
+	dst->thread.vm86 = NULL;
+#endif
 
 	return fpu__copy(&dst->thread.fpu, &src->thread.fpu);
 }
-- 
2.4.3


  parent reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-31  5:42 [PATCH urgent 0/2] x86: vm86 fix and test Andy Lutomirski
2015-10-31  5:42 ` [PATCH urgent 1/2] selftests/x86: Add a fork() to entry_from_vm86 to catch fork bugs Andy Lutomirski
2015-10-31  8:54   ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
2015-10-31  5:42 ` Andy Lutomirski [this message]
2015-10-31  8:55   ` [tip:x86/urgent] x86/vm86: Set thread.vm86 to NULL on fork/clone tip-bot for Andy Lutomirski

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