From 75b4770b3a0cc931efb3699c37f2c47869ce3338 Mon Sep 17 00:00:00 2001 From: Indira Biruduraju Date: Tue, 11 Aug 2020 15:24:16 +0530 Subject: [PATCH] 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 --- drivers/gpu/msm/kgsl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/msm/kgsl.c b/drivers/gpu/msm/kgsl.c index bfec37c2cddc..1b99f74801d5 100644 --- a/drivers/gpu/msm/kgsl.c +++ b/drivers/gpu/msm/kgsl.c @@ -3357,6 +3357,8 @@ kgsl_mmap_memstore(struct kgsl_device *device, struct vm_area_struct *vma) if (vma->vm_flags & VM_WRITE) return -EPERM; + vma->vm_flags &= ~VM_MAYWRITE; + if (memdesc->size != vma_size) { KGSL_MEM_ERR(device, "memstore bad size: %d should be %llu\n", vma_size, memdesc->size);