Commit 4cb19355 authored by Dan Williams's avatar Dan Williams

device-dax: fail all private mapping attempts

The device-dax implementation originally tried to be tricky and allow
private read-only mappings, but in the process allowed writable
MAP_PRIVATE + MAP_NORESERVE mappings.  For simplicity and predictability
just fail all private mapping attempts since device-dax memory is
statically allocated and will never support overcommit.

Cc: <stable@vger.kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Fixes: dee41079 ("/dev/dax, core: file operations and dax-mmap")
Reported-by: default avatarPawel Lebioda <pawel.lebioda@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 6a84fb4b
...@@ -270,8 +270,8 @@ static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, ...@@ -270,8 +270,8 @@ static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma,
if (!dax_dev->alive) if (!dax_dev->alive)
return -ENXIO; return -ENXIO;
/* prevent private / writable mappings from being established */ /* prevent private mappings from being established */
if ((vma->vm_flags & (VM_NORESERVE|VM_SHARED|VM_WRITE)) == VM_WRITE) { if ((vma->vm_flags & VM_SHARED) != VM_SHARED) {
dev_info(dev, "%s: %s: fail, attempted private mapping\n", dev_info(dev, "%s: %s: fail, attempted private mapping\n",
current->comm, func); current->comm, func);
return -EINVAL; return -EINVAL;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment