Originally "type" could be NULL and these checks were required, but we
recently changed how "type" is assigned and that's no longer the case.
Now "type" points to an element in the middle of a non-NULL array.
Removing the checks does not affect runtime at all, but it makes the
code a little bit simpler to read.
Fixes: 3d3a360e57 ("vfio/mbochs: Use mdev_get_type_group_id()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <20210429095327.GY1981@kadam>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Patch series "remap_vmalloc_range cleanups".
This series removes an open coded instance of remap_vmalloc_range and
removes the unused remap_vmalloc_range_partial export.
This patch (of 2):
Use remap_vmalloc_range instead of open coding it using
remap_vmalloc_range_partial.
Link: https://lkml.kernel.org/r/20210301082235.932968-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210301082235.932968-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The driver core standard is to pass in the properly typed object, the
properly typed attribute and the buffer data. It stems from the root
kobject method:
ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,..)
Each subclass of kobject should provide their own function with the same
signature but more specific types, eg struct device uses:
ssize_t (*show)(struct device *dev, struct device_attribute *attr,..)
In this case the existing signature is:
ssize_t (*show)(struct kobject *kobj, struct device *dev,..)
Where kobj is a 'struct mdev_type *' and dev is 'mdev_type->parent->dev'.
Change the mdev_type related sysfs attribute functions to:
ssize_t (*show)(struct mdev_type *mtype, struct mdev_type_attribute *attr,..)
In order to restore type safety and match the driver core standard
There are no current users of 'attr', but if it is ever needed it would be
hard to add in retroactively, so do it now.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <18-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The kobj here is a type-erased version of mdev_type, which is already
stored in the struct mdev_device being passed in. It was only ever used to
compute the type_group_id, which is now extracted directly from the mdev.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <17-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The mdpy_types array is parallel to the supported_type_groups array, so
the type_group_id indexes both. Instead of doing string searching just
directly index with type_group_id in all places.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <13-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
These should always be prefixed with static, otherwise compilation
will fail on non-modular builds with
ld: samples/vfio-mdev/mbochs.o:(.data+0x2e0): multiple definition of `mdev_type_attr_name'; samples/vfio-mdev/mdpy.o:(.data+0x240): first defined here
Fixes: a5e6e6505f ("sample: vfio bochs vbe display (host device for bochs-drm)")
Fixes: d61fc96f47 ("sample: vfio mdev display - host device")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <1-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:
- not detecting pgoff<<PAGE_SHIFT overflow
- not detecting (pgoff<<PAGE_SHIFT)+usize overflow
- not checking whether addr and addr+(pgoff<<PAGE_SHIFT) are the same
vmalloc allocation
- comparing a potentially wildly out-of-bounds pointer with the end of
the vmalloc region
In particular, since commit fc9702273e ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.
This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the possible address range.
To allow remap_vmalloc_range_partial() to verify that addr and
addr+(pgoff<<PAGE_SHIFT) are in the same vmalloc region, pass the offset
to remap_vmalloc_range_partial() instead of adding it to the pointer in
remap_vmalloc_range().
In remap_vmalloc_range_partial(), fix the check against
get_vm_area_size() by using size comparisons instead of pointer
comparisons, and add checks for pgoff.
Fixes: 833423143c ("[PATCH] mm: introduce remap_vmalloc_range()")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@chromium.org>
Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Actually, total amount of available minor number
for a single major is MINORMARK + 1. So expand
minor range when registering chrdev region.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Dan Carpenter