Just CC’ed to some of maintainers. $ perl scripts/get_maintainer.pl fs/0001-ksys_mount-check-for-permissions-before-resource-all.patch Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> (maintainer:FILESYSTEMS (VFS and infrastructure)) linux-fsdevel@xxxxxxxxxxxxxxx (open list:FILESYSTEMS (VFS and infrastructure)) linux-kernel@xxxxxxxxxxxxxxx (open list) > On Jun 5, 2018, at 6:00 AM, Ilya Matveychikov <matvejchikov@xxxxxxxxx> wrote: > > Early check for mount permissions prevents possible allocation of 3 > pages from kmalloc() pool by unpriveledged user which can be used for > spraying the kernel heap. > > Signed-off-by: Ilya V. Matveychikov <matvejchikov@xxxxxxxxx> > --- > fs/namespace.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/namespace.c b/fs/namespace.c > index 5f75969adff1..1ef8feb2de2a 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -3046,6 +3046,9 @@ int ksys_mount(char __user *dev_name, char __user *dir_name, char __user *type, > char *kernel_dev; > void *options; > > + if (!may_mount()) > + return -EPERM; > + > kernel_type = copy_mount_string(type); > ret = PTR_ERR(kernel_type); > if (IS_ERR(kernel_type)) > -- > 2.17.0 >
