Commit 02695347 authored by Yang Shen's avatar Yang Shen Committed by Greg Kroah-Hartman
Browse files

uacce: implement mremap in uacce_vm_ops to return -EPERM 



The current uacce_vm_ops does not support the mremap operation of
vm_operations_struct. Implement .mremap to return -EPERM to remind
users.

The reason we need to explicitly disable mremap is that when the
driver does not implement .mremap, it uses the default mremap
method. This could lead to a risk scenario:

An application might first mmap address p1, then mremap to p2,
followed by munmap(p1), and finally munmap(p2). Since the default
mremap copies the original vma's vm_private_data (i.e., q) to the
new vma, both munmap operations would trigger vma_close, causing
q->qfr to be freed twice(qfr will be set to null here, so repeated
release is ok).

Fixes: 015d239a ("uacce: add uacce driver")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarYang Shen <shenyang39@huawei.com>
Signed-off-by: default avatarChenghai Huang <huangchenghai2@huawei.com>
Acked-by: default avatarZhangfei Gao <zhangfei.gao@linaro.org>
Link: https://patch.msgid.link/20251202061256.4158641-4-huangchenghai2@huawei.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 98eec349

drivers/misc/uacce/uacce.c

+6 −0
Original line number Diff line number Diff line
@@ -214,8 +214,14 @@ static void uacce_vma_close(struct vm_area_struct *vma) 
	}

}



static int uacce_vma_mremap(struct vm_area_struct *area)

{

	return -EPERM;

}



static const struct vm_operations_struct uacce_vm_ops = {

	.close = uacce_vma_close,

	.mremap = uacce_vma_mremap,

};



static int uacce_fops_mmap(struct file *filep, struct vm_area_struct *vma)