Messages in this thread |  | | Date | Mon, 29 Jan 2018 02:54:22 -0800 | From | Kees Cook <> | Subject | [GIT PULL] hardened usercopy whitelisting for v4.16-rc1 |
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Hi Linus,
Please pull these hardened usercopy changes for v4.16-rc1. This is very close to what I sent for v4.15, though now it has a couple more Acks, I reorganized the WARN-by-default to be earlier in the series where hopefully it stands out better, and I improved reporting (while also dropping the nearly meaningless %p usage). The bulk of this series has been living happily in linux-next for almost two devel cycles now, so my impression is that it's baked well enough for prime-time.
One merge conflict with net (sctp) appeared about 3 weeks ago, which should prefer the usercopy version (since it uses a constant size for the copy). Noted here: https://lkml.org/lkml/2018/1/11/757
Thanks!
-Kees
The following changes since commit ae64f9bd1d3621b5e60d7363bc20afb46aede215:
Linux 4.15-rc2 (2017-12-03 11:01:47 -0500)
are available in the git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git tags/usercopy-v4.16-rc1
for you to fetch changes up to e47e311843dece8073146f3606871280ee9beb87:
lkdtm: Update usercopy tests for whitelisting (2018-01-15 12:08:09 -0800)
---------------------------------------------------------------- Currently, hardened usercopy performs dynamic bounds checking on slab cache objects. This is good, but still leaves a lot of kernel memory available to be copied to/from userspace in the face of bugs. To further restrict what memory is available for copying, this creates a way to whitelist specific areas of a given slab cache object for copying to/from userspace, allowing much finer granularity of access control. Slab caches that are never exposed to userspace can declare no whitelist for their objects, thereby keeping them unavailable to userspace via dynamic copy operations. (Note, an implicit form of whitelisting is the use of constant sizes in usercopy operations and get_user()/put_user(); these bypass all hardened usercopy checks since these sizes cannot change at runtime.)
This new check is WARN-by-default, so any mistakes can be found over the next several releases without breaking anyone's system.
The series has roughly the following sections: - remove %p and improve reporting with offset - prepare infrastructure and whitelist kmalloc - update VFS subsystem with whitelists - update SCSI subsystem with whitelists - update network subsystem with whitelists - update process memory with whitelists - update per-architecture thread_struct with whitelists - update KVM with whitelists and fix ioctl bug - mark all other allocations as not whitelisted - update lkdtm for more sensible test overage
---------------------------------------------------------------- David Windsor (22): usercopy: Prepare for usercopy whitelisting usercopy: Mark kmalloc caches as usercopy caches dcache: Define usercopy region in dentry_cache slab cache vfs: Define usercopy region in names_cache slab caches vfs: Copy struct mount.mnt_id to userspace using put_user() ext4: Define usercopy region in ext4_inode_cache slab cache ext2: Define usercopy region in ext2_inode_cache slab cache jfs: Define usercopy region in jfs_ip slab cache befs: Define usercopy region in befs_inode_cache slab cache exofs: Define usercopy region in exofs_inode_cache slab cache orangefs: Define usercopy region in orangefs_inode_cache slab cache ufs: Define usercopy region in ufs_inode_cache slab cache vxfs: Define usercopy region in vxfs_inode slab cache cifs: Define usercopy region in cifs_request slab cache scsi: Define usercopy region in scsi_sense_cache slab cache net: Define usercopy region in struct proto slab cache ip: Define usercopy region in IP proto slab cache caif: Define usercopy region in caif proto slab cache sctp: Define usercopy region in SCTP proto slab cache sctp: Copy struct sctp_sock.autoclose to userspace using put_user() fork: Define usercopy region in mm_struct slab caches fork: Define usercopy region in thread_stack slab caches
Kees Cook (14): usercopy: Remove pointer from overflow report usercopy: Enhance and rename report_usercopy() usercopy: Include offset in hardened usercopy report lkdtm/usercopy: Adjust test to include an offset to check reporting stddef.h: Introduce sizeof_field() usercopy: WARN() on slab cache usercopy region violations usercopy: Allow strict enforcement of whitelists net: Restrict unwhitelisted proto caches to size 0 fork: Provide usercopy whitelisting for task_struct x86: Implement thread_struct whitelist for hardened usercopy arm64: Implement thread_struct whitelist for hardened usercopy arm: Implement thread_struct whitelist for hardened usercopy usercopy: Restrict non-usercopy caches to size 0 lkdtm: Update usercopy tests for whitelisting
Paolo Bonzini (2): kvm: whitelist struct kvm_vcpu_arch kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
arch/Kconfig | 11 +++ arch/arm/Kconfig | 1 + arch/arm/include/asm/processor.h | 10 +++ arch/arm64/Kconfig | 1 + arch/arm64/include/asm/processor.h | 10 +++ arch/x86/Kconfig | 1 + arch/x86/include/asm/processor.h | 8 +++ arch/x86/kvm/x86.c | 7 +- drivers/misc/lkdtm.h | 4 +- drivers/misc/lkdtm_core.c | 4 +- drivers/misc/lkdtm_usercopy.c | 101 ++++++++++++++++------------ drivers/scsi/scsi_lib.c | 9 +-- fs/befs/linuxvfs.c | 14 ++-- fs/cifs/cifsfs.c | 10 +-- fs/dcache.c | 9 +-- fs/exofs/super.c | 7 +- fs/ext2/super.c | 12 ++-- fs/ext4/super.c | 12 ++-- fs/fhandle.c | 3 +- fs/freevxfs/vxfs_super.c | 8 ++- fs/jfs/super.c | 8 ++- fs/orangefs/super.c | 15 +++-- fs/ufs/super.c | 13 ++-- include/linux/sched/task.h | 14 ++++ include/linux/slab.h | 41 ++++++++---- include/linux/slab_def.h | 3 + include/linux/slub_def.h | 3 + include/linux/stddef.h | 10 ++- include/linux/uaccess.h | 8 +++ include/net/sctp/structs.h | 9 ++- include/net/sock.h | 2 + kernel/fork.c | 31 +++++++-- mm/slab.c | 36 +++++++--- mm/slab.h | 8 ++- mm/slab_common.c | 62 ++++++++++++++--- mm/slub.c | 49 ++++++++++---- mm/usercopy.c | 133 +++++++++++++++++++++---------------- net/caif/caif_socket.c | 2 + net/core/sock.c | 4 +- net/ipv4/raw.c | 2 + net/ipv6/raw.c | 2 + net/sctp/socket.c | 10 ++- security/Kconfig | 14 ++++ tools/objtool/check.c | 1 + virt/kvm/kvm_main.c | 8 ++- 45 files changed, 515 insertions(+), 215 deletions(-)
-- Kees Cook Pixel Security
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