1. 04 2月, 2013 8 次提交
  2. 20 12月, 2012 2 次提交
  3. 14 12月, 2012 1 次提交
    • K
      module: add syscall to load module from fd · 34e1169d
      Kees Cook 提交于
      As part of the effort to create a stronger boundary between root and
      kernel, Chrome OS wants to be able to enforce that kernel modules are
      being loaded only from our read-only crypto-hash verified (dm_verity)
      root filesystem. Since the init_module syscall hands the kernel a module
      as a memory blob, no reasoning about the origin of the blob can be made.
      
      Earlier proposals for appending signatures to kernel modules would not be
      useful in Chrome OS, since it would involve adding an additional set of
      keys to our kernel and builds for no good reason: we already trust the
      contents of our root filesystem. We don't need to verify those kernel
      modules a second time. Having to do signature checking on module loading
      would slow us down and be redundant. All we need to know is where a
      module is coming from so we can say yes/no to loading it.
      
      If a file descriptor is used as the source of a kernel module, many more
      things can be reasoned about. In Chrome OS's case, we could enforce that
      the module lives on the filesystem we expect it to live on.  In the case
      of IMA (or other LSMs), it would be possible, for example, to examine
      extended attributes that may contain signatures over the contents of
      the module.
      
      This introduces a new syscall (on x86), similar to init_module, that has
      only two arguments. The first argument is used as a file descriptor to
      the module and the second argument is a pointer to the NULL terminated
      string of module arguments.
      Signed-off-by: NKees Cook <keescook@chromium.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
      34e1169d
  4. 29 11月, 2012 1 次提交
  5. 01 10月, 2012 1 次提交
  6. 01 6月, 2012 1 次提交
    • C
      syscalls, x86: add __NR_kcmp syscall · d97b46a6
      Cyrill Gorcunov 提交于
      While doing the checkpoint-restore in the user space one need to determine
      whether various kernel objects (like mm_struct-s of file_struct-s) are
      shared between tasks and restore this state.
      
      The 2nd step can be solved by using appropriate CLONE_ flags and the
      unshare syscall, while there's currently no ways for solving the 1st one.
      
      One of the ways for checking whether two tasks share e.g.  mm_struct is to
      provide some mm_struct ID of a task to its proc file, but showing such
      info considered to be not that good for security reasons.
      
      Thus after some debates we end up in conclusion that using that named
      'comparison' syscall might be the best candidate.  So here is it --
      __NR_kcmp.
      
      It takes up to 5 arguments - the pids of the two tasks (which
      characteristics should be compared), the comparison type and (in case of
      comparison of files) two file descriptors.
      
      Lookups for pids are done in the caller's PID namespace only.
      
      At moment only x86 is supported and tested.
      
      [akpm@linux-foundation.org: fix up selftests, warnings]
      [akpm@linux-foundation.org: include errno.h]
      [akpm@linux-foundation.org: tweak comment text]
      Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
      Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Andrey Vagin <avagin@openvz.org>
      Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Glauber Costa <glommer@parallels.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Matt Helsley <matthltc@us.ibm.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Cc: Vasiliy Kulikov <segoon@openwall.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: Valdis.Kletnieks@vt.edu
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d97b46a6
  7. 23 3月, 2012 1 次提交
  8. 21 2月, 2012 1 次提交
  9. 18 11月, 2011 1 次提交