net: bpf: reject invalid shifts
authorRabin Vincent <rabin@rab.in>
Tue, 12 Jan 2016 19:17:08 +0000 (20:17 +0100)
committerDavid S. Miller <davem@davemloft.net>
Tue, 12 Jan 2016 22:06:53 +0000 (17:06 -0500)
commit229394e8e62a4191d592842cf67e80c62a492937
treeb16b3b389afb1bb660373bab3ec2f986d99a6e13
parent7aaed57c5c2890634cfadf725173c7c68ea4cb4f
net: bpf: reject invalid shifts

On ARM64, a BUG() is triggered in the eBPF JIT if a filter with a
constant shift that can't be encoded in the immediate field of the
UBFM/SBFM instructions is passed to the JIT.  Since these shifts
amounts, which are negative or >= regsize, are invalid, reject them in
the eBPF verifier and the classic BPF filter checker, for all
architectures.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel/bpf/verifier.c
net/core/filter.c