Re: [PATCH v6 00/10] virtiofsd: Add support for file security context at file creation

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

Queued

* Vivek Goyal (vgoyal@redhat.com) wrote:
> Hi,
> 
> This is V6 of the patches. I posted V5 here.
> 
> https://listman.redhat.com/archives/virtio-fs/2022-February/msg00012.html
> 
> This patch series basically allows client to send a security context 
> (which is expected to be xattr security.selinux and its content) to
> virtiofsd and it will set that security context on file during creation
> based on various settings. Hence, this patch series basically allows
> supporting SELinux with virtiofs.
> 
> There are primarily 3 modes.
> 
> - If no security context enabled, then it continues to create files without
>   security context.
> 
> - If security context is enabled and but security.selinux has not been
>   remapped, then it uses /proc/thread-self/attr/fscreate knob to set
>   security context and then create the file. This will make sure that
>   newly created file gets the security context as set in "fscreate" and
>   this is atomic w.r.t file creation.
> 
>   This is useful and host and guest SELinux policies don't conflict and
>   can work with each other. In that case, guest security.selinux xattr
>   is not remapped and it is passthrough as "security.selinux" xattr
>   on host.
> 
> - If security context is enabled but security.selinux xattr has been
>   remapped to something else, then it first creates the file and then
>   uses setxattr() to set the remapped xattr with the security context.
>   This is a non-atomic operation w.r.t file creation.
> 
>   This mode will be most versatile and allow host and guest to have their
>   own separate SELinux xattrs and have their own separate SELinux policies.
> 
> Changes since V5:
> 
> - Added some documentation to recommend using xattr remapping to remap
>   "security.selinux" to "trusted.virtiofs.security.selinux" and also 
>   give CAP_SYS_ADMIN to daemon. Also put a warning to make users aware
>   of trade-off involved here. ("Daniel P. Berrangé")
> 
> - Used macro endof() to determine end of fuse_init_in struct. (David
>   Gilbert).
> 
> - Added a check to make sure fsecctx->size is not zero. Also added
>   "return" statement at few places where it was required. (David Gilbert)
> 
> - Split patch 7 in the series. Some of the handling of setting and
>   clearing fscreate knob has been moved into a separate patch. Found
>   it hard to break it down further. So it helps a bit but not too
>   much. (David Gilbert).
> 
> Thanks
> Vivek
> 
> Vivek Goyal (10):
>   virtiofsd: Fix breakage due to fuse_init_in size change
>   linux-headers: Update headers to v5.17-rc1
>   virtiofsd: Parse extended "struct fuse_init_in"
>   virtiofsd: Extend size of fuse_conn_info->capable and ->want fields
>   virtiofsd, fuse_lowlevel.c: Add capability to parse security context
>   virtiofsd: Move core file creation code in separate function
>   virtiofsd: Add helpers to work with /proc/self/task/tid/attr/fscreate
>   virtiofsd: Create new file with security context
>   virtiofsd: Create new file using O_TMPFILE and set security context
>   virtiofsd: Add an option to enable/disable security label
> 
>  docs/tools/virtiofsd.rst                      |  32 ++
>  include/standard-headers/asm-x86/kvm_para.h   |   1 +
>  include/standard-headers/drm/drm_fourcc.h     |  11 +
>  include/standard-headers/linux/ethtool.h      |   1 +
>  include/standard-headers/linux/fuse.h         |  60 ++-
>  include/standard-headers/linux/pci_regs.h     | 142 +++---
>  include/standard-headers/linux/virtio_gpio.h  |  72 +++
>  include/standard-headers/linux/virtio_i2c.h   |  47 ++
>  include/standard-headers/linux/virtio_iommu.h |   8 +-
>  .../standard-headers/linux/virtio_pcidev.h    |  65 +++
>  include/standard-headers/linux/virtio_scmi.h  |  24 +
>  linux-headers/asm-generic/unistd.h            |   5 +-
>  linux-headers/asm-mips/unistd_n32.h           |   2 +
>  linux-headers/asm-mips/unistd_n64.h           |   2 +
>  linux-headers/asm-mips/unistd_o32.h           |   2 +
>  linux-headers/asm-powerpc/unistd_32.h         |   2 +
>  linux-headers/asm-powerpc/unistd_64.h         |   2 +
>  linux-headers/asm-riscv/bitsperlong.h         |  14 +
>  linux-headers/asm-riscv/mman.h                |   1 +
>  linux-headers/asm-riscv/unistd.h              |  44 ++
>  linux-headers/asm-s390/unistd_32.h            |   2 +
>  linux-headers/asm-s390/unistd_64.h            |   2 +
>  linux-headers/asm-x86/kvm.h                   |  16 +-
>  linux-headers/asm-x86/unistd_32.h             |   1 +
>  linux-headers/asm-x86/unistd_64.h             |   1 +
>  linux-headers/asm-x86/unistd_x32.h            |   1 +
>  linux-headers/linux/kvm.h                     |  17 +
>  tools/virtiofsd/fuse_common.h                 |   9 +-
>  tools/virtiofsd/fuse_i.h                      |   7 +
>  tools/virtiofsd/fuse_lowlevel.c               | 168 +++++--
>  tools/virtiofsd/helper.c                      |   1 +
>  tools/virtiofsd/passthrough_ll.c              | 414 ++++++++++++++++--
>  32 files changed, 1044 insertions(+), 132 deletions(-)
>  create mode 100644 include/standard-headers/linux/virtio_gpio.h
>  create mode 100644 include/standard-headers/linux/virtio_i2c.h
>  create mode 100644 include/standard-headers/linux/virtio_pcidev.h
>  create mode 100644 include/standard-headers/linux/virtio_scmi.h
>  create mode 100644 linux-headers/asm-riscv/bitsperlong.h
>  create mode 100644 linux-headers/asm-riscv/mman.h
>  create mode 100644 linux-headers/asm-riscv/unistd.h
> 
> -- 
> 2.34.1
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK