Commit af6de62c authored Aug 11, 2020 by Indira Biruduraju

msm: kgsl: Remove VM_MAYWRITE flag to restrict mprotect



When VM_MAYWRITE flag is used during mmap(), mprotect()
can be used later to change the protection of memstore
to allow write. Make sure this does not happen by
removing VM_MAYWRITE from the vm_flags of vma.

Change-Id: I6f69f05858ea40611d512cfa796caabeaa88cdb5
Signed-off-by: Indira Biruduraju <ibirudur@codeaurora.org>

parent b490abfe

drivers/gpu/msm/kgsl.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -4301,6 +4301,8 @@ kgsl_mmap_memstore(struct file file, struct kgsl_device device,
		if (vma->vm_flags & VM_WRITE)
		return -EPERM;

		vma->vm_flags &= ~VM_MAYWRITE;

		if (memdesc->size != vma_size) {
		dev_err(device->dev, "Cannot partially map the memstore\n");
		return -EINVAL;