https://github.com/torvalds/linux
Revision 55795ef5469290f89f04e12e662ded604909e462 authored by Rabin Vincent on 05 January 2016, 15:23:07 UTC, committed by David S. Miller on 06 January 2016, 05:43:52 UTC
The SKF_AD_ALU_XOR_X ancillary is not like the other ancillary data
instructions since it XORs A with X while all the others replace A with
some loaded value.  All the BPF JITs fail to clear A if this is used as
the first instruction in a filter.  This was found using american fuzzy
lop.

Add a helper to determine if A needs to be cleared given the first
instruction in a filter, and use this in the JITs.  Except for ARM, the
rest have only been compile-tested.

Fixes: 3480593131e0 ("net: filter: get rid of BPF_S_* enum")
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent ff62198
History
Tip revision: 55795ef5469290f89f04e12e662ded604909e462 authored by Rabin Vincent on 05 January 2016, 15:23:07 UTC
net: filter: make JITs zero A for SKF_AD_ALU_XOR_X
Tip revision: 55795ef

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