Re: [PATCH 4.4-stable 6/6] bpf: prevent out-of-bounds speculation

2018-01-12 Thread Eric Dumazet
On Fri, 2018-01-12 at 17:17 +0100, Jiri Slaby wrote: > From: Alexei Starovoitov > > commit b2157399cc9898260d6031c5bfe45fe137c1fbe7 upstream. > > Under speculation, CPUs may mis-predict branches in bounds checks. Thus, > memory accesses under a bounds check may be speculated even if the > bounds

[PATCH 4.4-stable 6/6] bpf: prevent out-of-bounds speculation

2018-01-12 Thread Jiri Slaby
From: Alexei Starovoitov commit b2157399cc9898260d6031c5bfe45fe137c1fbe7 upstream. Under speculation, CPUs may mis-predict branches in bounds checks. Thus, memory accesses under a bounds check may be speculated even if the bounds check fails, providing a primitive for building a side channel. T