1. 06 3月, 2014 1 次提交
  2. 06 2月, 2014 1 次提交
    • L
      execve: use 'struct filename *' for executable name passing · c4ad8f98
      Linus Torvalds 提交于
      This changes 'do_execve()' to get the executable name as a 'struct
      filename', and to free it when it is done.  This is what the normal
      users want, and it simplifies and streamlines their error handling.
      
      The controlled lifetime of the executable name also fixes a
      use-after-free problem with the trace_sched_process_exec tracepoint: the
      lifetime of the passed-in string for kernel users was not at all
      obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize
      the pathname allocation lifetime with the execve() having finished,
      which in turn meant that the trace point that happened after
      mm_release() of the old process VM ended up using already free'd memory.
      
      To solve the kernel string lifetime issue, this simply introduces
      "getname_kernel()" that works like the normal user-space getname()
      function, except with the source coming from kernel memory.
      
      As Oleg points out, this also means that we could drop the tcomm[] array
      from 'struct linux_binprm', since the pathname lifetime now covers
      setup_new_exec().  That would be a separate cleanup.
      Reported-by: NIgor Zhbanov <i.zhbanov@samsung.com>
      Tested-by: NSteven Rostedt <rostedt@goodmis.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c4ad8f98
  3. 24 1月, 2014 9 次提交
  4. 13 11月, 2013 1 次提交
    • K
      exec/ptrace: fix get_dumpable() incorrect tests · d049f74f
      Kees Cook 提交于
      The get_dumpable() return value is not boolean.  Most users of the
      function actually want to be testing for non-SUID_DUMP_USER(1) rather than
      SUID_DUMP_DISABLE(0).  The SUID_DUMP_ROOT(2) is also considered a
      protected state.  Almost all places did this correctly, excepting the two
      places fixed in this patch.
      
      Wrong logic:
          if (dumpable == SUID_DUMP_DISABLE) { /* be protective */ }
              or
          if (dumpable == 0) { /* be protective */ }
              or
          if (!dumpable) { /* be protective */ }
      
      Correct logic:
          if (dumpable != SUID_DUMP_USER) { /* be protective */ }
              or
          if (dumpable != 1) { /* be protective */ }
      
      Without this patch, if the system had set the sysctl fs/suid_dumpable=2, a
      user was able to ptrace attach to processes that had dropped privileges to
      that user.  (This may have been partially mitigated if Yama was enabled.)
      
      The macros have been moved into the file that declares get/set_dumpable(),
      which means things like the ia64 code can see them too.
      
      CVE-2013-2929
      Reported-by: NVasily Kulikov <segoon@openwall.com>
      Signed-off-by: NKees Cook <keescook@chromium.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d049f74f
  5. 06 11月, 2013 1 次提交
    • R
      audit: call audit_bprm() only once to add AUDIT_EXECVE information · 9410d228
      Richard Guy Briggs 提交于
      Move the audit_bprm() call from search_binary_handler() to exec_binprm().  This
      allows us to get rid of the mm member of struct audit_aux_data_execve since
      bprm->mm will equal current->mm.
      
      This also mitigates the issue that ->argc could be modified by the
      load_binary() call in search_binary_handler().
      
      audit_bprm() was being called to add an AUDIT_EXECVE record to the audit
      context every time search_binary_handler() was recursively called.  Only one
      reference is necessary.
      Reported-by: NOleg Nesterov <onestero@redhat.com>
      Cc: Eric Paris <eparis@redhat.com>
      Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
      Signed-off-by: NEric Paris <eparis@redhat.com>
      ---
      This patch is against 3.11, but was developed on Oleg's post-3.11 patches that
      introduce exec_binprm().
      9410d228
  6. 25 10月, 2013 1 次提交
  7. 09 10月, 2013 1 次提交
  8. 12 9月, 2013 9 次提交
  9. 16 8月, 2013 1 次提交
    • L
      Fix TLB gather virtual address range invalidation corner cases · 2b047252
      Linus Torvalds 提交于
      Ben Tebulin reported:
      
       "Since v3.7.2 on two independent machines a very specific Git
        repository fails in 9/10 cases on git-fsck due to an SHA1/memory
        failures.  This only occurs on a very specific repository and can be
        reproduced stably on two independent laptops.  Git mailing list ran
        out of ideas and for me this looks like some very exotic kernel issue"
      
      and bisected the failure to the backport of commit 53a59fc6 ("mm:
      limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").
      
      That commit itself is not actually buggy, but what it does is to make it
      much more likely to hit the partial TLB invalidation case, since it
      introduces a new case in tlb_next_batch() that previously only ever
      happened when running out of memory.
      
      The real bug is that the TLB gather virtual memory range setup is subtly
      buggered.  It was introduced in commit 597e1c35 ("mm/mmu_gather:
      enable tlb flush range in generic mmu_gather"), and the range handling
      was already fixed at least once in commit e6c495a9 ("mm: fix the TLB
      range flushed when __tlb_remove_page() runs out of slots"), but that fix
      was not complete.
      
      The problem with the TLB gather virtual address range is that it isn't
      set up by the initial tlb_gather_mmu() initialization (which didn't get
      the TLB range information), but it is set up ad-hoc later by the
      functions that actually flush the TLB.  And so any such case that forgot
      to update the TLB range entries would potentially miss TLB invalidates.
      
      Rather than try to figure out exactly which particular ad-hoc range
      setup was missing (I personally suspect it's the hugetlb case in
      zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
      did), this patch just gets rid of the problem at the source: make the
      TLB range information available to tlb_gather_mmu(), and initialize it
      when initializing all the other tlb gather fields.
      
      This makes the patch larger, but conceptually much simpler.  And the end
      result is much more understandable; even if you want to play games with
      partial ranges when invalidating the TLB contents in chunks, now the
      range information is always there, and anybody who doesn't want to
      bother with it won't introduce subtle bugs.
      
      Ben verified that this fixes his problem.
      Reported-bisected-and-tested-by: NBen Tebulin <tebulin@googlemail.com>
      Build-testing-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Build-testing-by: NRichard Weinberger <richard.weinberger@gmail.com>
      Reviewed-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: stable@vger.kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2b047252
  10. 04 7月, 2013 3 次提交
  11. 29 6月, 2013 1 次提交
  12. 26 6月, 2013 1 次提交
  13. 01 5月, 2013 2 次提交
  14. 30 4月, 2013 2 次提交
  15. 25 4月, 2013 1 次提交
  16. 28 2月, 2013 1 次提交
  17. 26 2月, 2013 1 次提交
  18. 23 2月, 2013 1 次提交
  19. 12 1月, 2013 1 次提交
    • X
      fs/exec.c: work around icc miscompilation · 6d92d4f6
      Xi Wang 提交于
      The tricky problem is this check:
      
      	if (i++ >= max)
      
      icc (mis)optimizes this check as:
      
      	if (++i > max)
      
      The check now becomes a no-op since max is MAX_ARG_STRINGS (0x7FFFFFFF).
      
      This is "allowed" by the C standard, assuming i++ never overflows,
      because signed integer overflow is undefined behavior.  This
      optimization effectively reverts the previous commit 362e6663
      ("exec.c, compat.c: fix count(), compat_count() bounds checking") that
      tries to fix the check.
      
      This patch simply moves ++ after the check.
      Signed-off-by: NXi Wang <xi.wang@gmail.com>
      Cc: Jason Baron <jbaron@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6d92d4f6
  20. 21 12月, 2012 1 次提交
    • K
      exec: do not leave bprm->interp on stack · b66c5984
      Kees Cook 提交于
      If a series of scripts are executed, each triggering module loading via
      unprintable bytes in the script header, kernel stack contents can leak
      into the command line.
      
      Normally execution of binfmt_script and binfmt_misc happens recursively.
      However, when modules are enabled, and unprintable bytes exist in the
      bprm->buf, execution will restart after attempting to load matching
      binfmt modules.  Unfortunately, the logic in binfmt_script and
      binfmt_misc does not expect to get restarted.  They leave bprm->interp
      pointing to their local stack.  This means on restart bprm->interp is
      left pointing into unused stack memory which can then be copied into the
      userspace argv areas.
      
      After additional study, it seems that both recursion and restart remains
      the desirable way to handle exec with scripts, misc, and modules.  As
      such, we need to protect the changes to interp.
      
      This changes the logic to require allocation for any changes to the
      bprm->interp.  To avoid adding a new kmalloc to every exec, the default
      value is left as-is.  Only when passing through binfmt_script or
      binfmt_misc does an allocation take place.
      
      For a proof of concept, see DoTest.sh from:
      
         http://www.halfdog.net/Security/2012/LinuxKernelBinfmtScriptStackDataDisclosure/Signed-off-by: NKees Cook <keescook@chromium.org>
      Cc: halfdog <me@halfdog.net>
      Cc: P J P <ppandit@redhat.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b66c5984