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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-03 16:25:42 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-03 16:25:42 -0800 |
commit | 617aebe6a97efa539cc4b8a52adccd89596e6be0 (patch) | |
tree | 51c7753c940fd3727b8cc3e93553c57f89d1d9d2 /mm/slab.h | |
parent | 0771ad44a20bc512d1123bac728d3a89ea6febe6 (diff) | |
parent | e47e311843dece8073146f3606871280ee9beb87 (diff) | |
download | linux-stable-617aebe6a97efa539cc4b8a52adccd89596e6be0.tar.gz linux-stable-617aebe6a97efa539cc4b8a52adccd89596e6be0.tar.bz2 linux-stable-617aebe6a97efa539cc4b8a52adccd89596e6be0.zip |
Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardened usercopy whitelisting from Kees Cook:
"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"
* tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits)
lkdtm: Update usercopy tests for whitelisting
usercopy: Restrict non-usercopy caches to size 0
kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
kvm: whitelist struct kvm_vcpu_arch
arm: Implement thread_struct whitelist for hardened usercopy
arm64: Implement thread_struct whitelist for hardened usercopy
x86: Implement thread_struct whitelist for hardened usercopy
fork: Provide usercopy whitelisting for task_struct
fork: Define usercopy region in thread_stack slab caches
fork: Define usercopy region in mm_struct slab caches
net: Restrict unwhitelisted proto caches to size 0
sctp: Copy struct sctp_sock.autoclose to userspace using put_user()
sctp: Define usercopy region in SCTP proto slab cache
caif: Define usercopy region in caif proto slab cache
ip: Define usercopy region in IP proto slab cache
net: Define usercopy region in struct proto slab cache
scsi: Define usercopy region in scsi_sense_cache slab cache
cifs: Define usercopy region in cifs_request slab cache
vxfs: Define usercopy region in vxfs_inode slab cache
ufs: Define usercopy region in ufs_inode_cache slab cache
...
Diffstat (limited to 'mm/slab.h')
-rw-r--r-- | mm/slab.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/slab.h b/mm/slab.h index e8e2095a6185..51813236e773 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -22,6 +22,8 @@ struct kmem_cache { unsigned int size; /* The aligned/padded/added on size */ unsigned int align; /* Alignment as calculated */ slab_flags_t flags; /* Active flags on the slab */ + size_t useroffset; /* Usercopy region offset */ + size_t usersize; /* Usercopy region size */ const char *name; /* Slab name for sysfs */ int refcount; /* Use counter */ void (*ctor)(void *); /* Called on object slot creation */ @@ -92,9 +94,11 @@ struct kmem_cache *kmalloc_slab(size_t, gfp_t); int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size, - slab_flags_t flags); + slab_flags_t flags, size_t useroffset, + size_t usersize); extern void create_boot_cache(struct kmem_cache *, const char *name, - size_t size, slab_flags_t flags); + size_t size, slab_flags_t flags, size_t useroffset, + size_t usersize); int slab_unmergeable(struct kmem_cache *s); struct kmem_cache *find_mergeable(size_t size, size_t align, |