Messages in this thread | | | Date | Wed, 10 Sep 2014 10:27:12 -0400 | From | Dave Jones <> | Subject | Re: [PATCH] mm/sl[aou]b: make kfree() aware of error pointers |
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On Wed, Sep 10, 2014 at 09:56:49AM -0400, Theodore Ts'o wrote:
> The ironic thing is that I asked Dan to add the feature to smatch > because I found two such bugs in ext4, and I suspected there would be > more. Sure enough, it found four more such bugs, including two in a > recent commit where I had found the first two bugs --- and I had > missed the other two even though I was specifically looking for such > instances. Oops. :-) > > Maybe we can add a debugging config option? I think having static > checkers plus some kmalloc failure testing should be sufficient to > prevent these sorts of problem from showing up. > > It would seem to me that this is the sort of thing that a static > checker should find reliably; Coverity has found things that were more > complex than what this should require, I think. I don't know if they > would be willing to add something this kernel-specific, though. (I've > added Dave Jones to the thread since he's been working a lot with > Coverity; Dave, what do you think?)
It *might* be possible to rig up something using their modelling functionality, but I've not managed to make that work to my ends in the past.
I suspect a runtime check would be more fruitful faster than they could implement kernel specific checkers & roll them out.
Dave
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