Messages in this thread | | | Date | Thu, 2 Apr 2009 23:42:19 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] - Fix slab corruption caused by alloc_cpumask_var_node() |
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* Jack Steiner <steiner@sgi.com> wrote:
> Fix for slab corruption caused by alloc_cpumask_var_node() overwriting > the tail end of an off-stack cpumask. > > Signed-off-by: Jack Steiner <steiner@sgi.com> > Acked-by: Mike Travis <travis.sgi.com> > > > --- > > Corrruption was found in latest linux-next (4/1) > v2.6.29-12081-g421a9f3 > > > > lib/cpumask.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Index: linux/lib/cpumask.c > =================================================================== > --- linux.orig/lib/cpumask.c 2009-04-02 15:30:05.000000000 -0500 > +++ linux/lib/cpumask.c 2009-04-02 15:57:44.000000000 -0500 > @@ -109,10 +109,10 @@ bool alloc_cpumask_var_node(cpumask_var_ > #endif > /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */ > if (*mask) { > + unsigned char *ptr = (unsigned char *)cpumask_bits(*mask); > unsigned int tail; > tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long); > - memset(cpumask_bits(*mask) + cpumask_size() - tail, > - 0, tail); > + memset(ptr + cpumask_size() - tail, 0, tail);
Nice,
Acked-by: Ingo Molnar <mingo@elte.hu>
Note: it also needs a Cc: <stable@kernel.org> tag as v2.6.29 is affected by this bug too.
Ingo
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