net_sched: reject TCF_EM_SIMPLE case for complex ematch module

When TCF_EM_SIMPLE was introduced, it is supposed to be convenient
for ematch implementation:

https://lore.kernel.org/all/[email protected]/

"You don't have to, providing a 32bit data chunk without TCF_EM_SIMPLE
set will simply result in allocating & copy. It's an optimization,
nothing more."

So if an ematch module provides ops->datalen that means it wants a
complex data structure (saved in its em->data) instead of a simple u32
value. We should simply reject such a combination, otherwise this u32
could be misinterpreted as a pointer.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: [email protected]
Reported-by: Jun Nie <[email protected]>
Cc: Jamal Hadi Salim <[email protected]>
Cc: Paolo Abeni <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Acked-by: Paolo Abeni <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions