1. 27 11月, 2010 6 次提交
  2. 21 11月, 2010 1 次提交
  3. 19 11月, 2010 12 次提交
  4. 18 11月, 2010 20 次提交
  5. 17 11月, 2010 1 次提交
    • M
      kernel: make /proc/kallsyms mode 400 to reduce ease of attacking · 59365d13
      Marcus Meissner 提交于
      Making /proc/kallsyms readable only for root by default makes it
      slightly harder for attackers to write generic kernel exploits by
      removing one source of knowledge where things are in the kernel.
      
      This is the second submit, discussion happened on this on first submit
      and mostly concerned that this is just one hole of the sieve ...  but
      one of the bigger ones.
      
      Changing the permissions of at least System.map and vmlinux is also
      required to fix the same set, but a packaging issue.
      
      Target of this starter patch and follow ups is removing any kind of
      kernel space address information leak from the kernel.
      
      [ Side note: the default of root-only reading is the "safe" value, and
        it's easy enough to then override at any time after boot.  The /proc
        filesystem allows root to change the permissions with a regular
        chmod, so you can "revert" this at run-time by simply doing
      
          chmod og+r /proc/kallsyms
      
        as root if you really want regular users to see the kernel symbols.
        It does help some tools like "perf" figure them out without any
        setup, so it may well make sense in some situations.  - Linus ]
      Signed-off-by: NMarcus Meissner <meissner@suse.de>
      Acked-by: NTejun Heo <tj@kernel.org>
      Acked-by: NEugene Teo <eugeneteo@kernel.org>
      Reviewed-by: NJesper Juhl <jj@chaosbits.net>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      59365d13