1. 19 Feb, 2011 1 commit
    • Thomas Gleixner's avatar
      genirq: Prevent access beyond allocated_irqs bitmap · c1ee6264
      Thomas Gleixner authored
      Lars-Peter Clausen pointed out:
      
         I stumbled upon this while looking through the existing archs using
         SPARSE_IRQ.  Even with SPARSE_IRQ the NR_IRQS is still the upper
         limit for the number of IRQs.
      
         Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with
         IRQ_BOARD_START being the number of IRQs used by the core.
      
         In various machine files the nr_irqs field of the ARM machine
         defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS".
      
         As a result "nr_irqs" will greater then NR_IRQS which then again
         causes the "allocated_irqs" bitmap in the core irq code to be
         accessed beyond its size overwriting unrelated data.
      
      The core code really misses a sanity check there.
      
      This went unnoticed so far as by chance the compiler/linker places
      data behind that bitmap which gets initialized later on those affected
      platforms.
      
      So the obvious fix would be to add a sanity check in early_irq_init()
      and break all affected platforms. Though that check wants to be
      backported to stable as well, which will require to fix all known
      problematic platforms and probably some more yet not known ones as
      well. Lots of churn.
      
      A way simpler solution is to allocate a slightly larger bitmap and
      avoid the whole churn w/o breaking anything. Add a few warnings when
      an arch returns utter crap.
      Reported-by: default avatarLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: stable@kernel.org # .37
      Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
      Cc: Eric Miao <eric.y.miao@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      c1ee6264
  2. 18 Feb, 2011 13 commits
  3. 17 Feb, 2011 19 commits
  4. 16 Feb, 2011 7 commits