The following commit has been merged into the x86/fpu branch of tip: Commit-ID: f0cbc8b3cdf7d1c724155cd9cecffe329bb96119 Gitweb: https://git.kernel.org/tip/f0cbc8b3cdf7d1c724155cd9cecffe329bb96119 Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Wed, 13 Oct 2021 16:55:43 +02:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Thu, 21 Oct 2021 09:32:41 +02:00 x86/fpu: Do not leak fpstate pointer on fork If fork fails early then the copied task struct would carry the fpstate pointer of the parent task. Not a problem right now, but later when dynamically allocated buffers are available, keeping the pointer might result in freeing the parent's buffer. Set it to NULL which prevents that. If fork reaches clone_thread(), the pointer will be correctly set to the new task context. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lkml.kernel.org/r/20211013145322.817101108@xxxxxxxxxxxxx --- arch/x86/kernel/process.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 5cd8208..c74c7e8 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -87,6 +87,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) #ifdef CONFIG_VM86 dst->thread.vm86 = NULL; #endif + /* Drop the copied pointer to current's fpstate */ + dst->thread.fpu.fpstate = NULL; return 0; }
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