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    SubjectRe: [PATCH] Fix for binary_sysctl() memory leak
    On Thu, 15 Dec 2011 14:38:58 -0800
    Michel Lespinasse <walken@google.com> wrote:

    > On Thu, Dec 15, 2011 at 2:19 PM, Andrew Morton
    > <akpm@linux-foundation.org> wrote:
    > > I think the patch is correct but the description is misleading?
    > >
    > > I see no memory leak here. __Calling __putname() directly simply
    > > bypasses some audit-related stuff.
    >
    > Hmmm, maybe I wasn't explicit enough about it. We are definitely
    > seeing a memory leak without the patch.
    >
    > When auditing is enabled, putname() calls audit_putname *instead* (not
    > in addition) to __putname(). Then, if a syscall is in progress,
    > audit_putname does not release the name - instead, it expects the name
    > to get released when the syscall completes, but that will happen only
    > if audit_getname() was called previously, i.e. if the name was
    > allocated with getname() rather than the naked __getname(). So,
    > __getname() followed by putname() ends up leaking memory.
    >

    OK. Please resend with a new changelog?

    The bug surprises me - it seems that it makes it trivial for userspace
    to cause leaking of mad amounts of kernel memory, which would cause the
    bug to be found and fixed quickly.

    Is it a recent regression, or does the bug trigger only in weird
    circumstances, or what?




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