Re: [PATCH] padata: use integer wrap around to prevent deadlock on seq_nr overflow

[Herbert Xu <herbert@gondor.apana.org.au>]

VanGiang Nguyen <vangiang.nguyen@rohde-schwarz.com> wrote:
> When submitting more than 2^32 padata objects to padata_do_serial, the
> current sorting implementation incorrectly sorts padata objects with
> overflowed seq_nr, causing them to be placed before existing objects in
> the reorder list. This leads to a deadlock in the serialization process
> as padata_find_next cannot match padata->seq_nr and pd->processed
> because the padata instance with overflowed seq_nr will be selected
> next.
> 
> To fix this, we use an unsigned integer wrap around to correctly sort
> padata objects in scenarios with integer overflow.
> 
> Co-developed-by: Christian Gafert <christian.gafert@rohde-schwarz.com>
> Signed-off-by: Christian Gafert <christian.gafert@rohde-schwarz.com>
> Co-developed-by: Max Ferger <max.ferger@rohde-schwarz.com>
> Signed-off-by: Max Ferger <max.ferger@rohde-schwarz.com>
> Signed-off-by: Van Giang Nguyen <vangiang.nguyen@rohde-schwarz.com>
> ---
> kernel/padata.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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