From a231637f3243b36685d3753581a16faef1998233 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= Date: Thu, 15 Jul 2010 16:31:16 -0700 Subject: [PATCH] ashmem: Fix ASHMEM_SET_PROT_MASK. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Change-Id: I1412cc9560de8c4feb1162fc30922f0e3362a476 Signed-off-by: Arve Hjønnevåg --- mm/ashmem.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/mm/ashmem.c b/mm/ashmem.c index 04e886e2c909..7b75f41a2d40 100644 --- a/mm/ashmem.c +++ b/mm/ashmem.c @@ -236,6 +236,14 @@ out: return ret; } +static inline unsigned long +calc_vm_may_flags(unsigned long prot) +{ + return _calc_vm_trans(prot, PROT_READ, VM_MAYREAD ) | + _calc_vm_trans(prot, PROT_WRITE, VM_MAYWRITE) | + _calc_vm_trans(prot, PROT_EXEC, VM_MAYEXEC); +} + static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) { struct ashmem_area *asma = file->private_data; @@ -250,10 +258,12 @@ static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) } /* requested protection bits must match our allowed protection mask */ - if (unlikely((vma->vm_flags & ~asma->prot_mask) & PROT_MASK)) { + if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask)) & + calc_vm_prot_bits(PROT_MASK))) { ret = -EPERM; goto out; } + vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask); if (!asma->file) { char *name = ASHMEM_NAME_DEF; -- 2.34.1