On 2018/7/6 4:56, Jann Horn wrote:
On Thu, Jul 5, 2018 at 10:53 PM <[email protected]> wrote:
From: Xiubo Li <[email protected]>
For the target_core_user use case, after the device is unregistered
it maybe still opened in user space, then the kernel will crash, like:
[...]
Signed-off-by: Xiubo Li <[email protected]>
---
drivers/uio/uio.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 86 insertions(+), 15 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 33c3bfe..2b9268a 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
[...]
@@ -720,30 +775,46 @@ static int uio_mmap(struct file *filep, struct
vm_area_struct *vma)
vma->vm_private_data = idev;
+ mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ ret = -EINVAL;
+ goto out;
+ }
+
mi = uio_find_mem_index(vma);
- if (mi < 0)
- return -EINVAL;
+ if (mi < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
requested_pages = vma_pages(vma);
actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
+ idev->info->mem[mi].size + PAGE_SIZE -1) >>
PAGE_SHIFT;
- if (requested_pages > actual_pages)
- return -EINVAL;
+ if (requested_pages > actual_pages) {
+ ret = -EINVAL;
+ goto out;
+ }
if (idev->info->mmap) {
ret = idev->info->mmap(idev->info, vma);
- return ret;
+ goto out;
}
switch (idev->info->mem[mi].memtype) {
case UIO_MEM_PHYS:
- return uio_mmap_physical(vma);
+ ret = uio_mmap_physical(vma);
+ break;
case UIO_MEM_LOGICAL:
case UIO_MEM_VIRTUAL:
- return uio_mmap_logical(vma);
+ ret = uio_mmap_logical(vma);
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
+
+out:
+ mutex_lock(&idev->info_lock);
This is probably supposed to be mutex_unlock(...)?
Yeah yeah, right, Good catch :-)
Locally I had fixed this, but after my building and testing just forgot
to amend it.
Will fix it.
Thanks very much.
BRs
