From f2da6274a5f9d858a6a81f1f11966f42e476f1f3 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Tue, 12 Jan 2016 20:17:08 +0100 Subject: net: bpf: reject invalid shifts [ Upstream commit 229394e8e62a4191d592842cf67e80c62a492937 ] 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 Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/filter.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index bb18c3680001..49b44879dc7f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -781,6 +781,11 @@ static int bpf_check_classic(const struct sock_filter *filter, if (ftest->k == 0) return -EINVAL; break; + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU | BPF_RSH | BPF_K: + if (ftest->k >= 32) + return -EINVAL; + break; case BPF_LD | BPF_MEM: case BPF_LDX | BPF_MEM: case BPF_ST: -- cgit v1.2.3