Messages in this thread | | | Date | Thu, 25 Jun 2015 15:26:29 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH] arm64: bpf: fix out-of-bounds read in bpf2a64_offset() |
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On Thu, Jun 25, 2015 at 05:47:39AM -0700, Xi Wang wrote: > Problems occur when bpf_to or bpf_from has value prog->len - 1 (e.g., > "Very long jump backwards" in test_bpf where the last instruction is a > jump): since ctx->offset has length prog->len, ctx->offset[bpf_to + 1] > or ctx->offset[bpf_from + 1] will cause an out-of-bounds read, leading > to a bogus jump offset and kernel panic. > > This patch moves updating ctx->offset to after calling build_insn(), > and changes indexing to use bpf_to and bpf_from without + 1. > > Cc: Zi Shen Lim <zlim.lnx@gmail.com> > Cc: Alexei Starovoitov <ast@plumgrid.com> > Cc: Will Deacon <will.deacon@arm.com> > Fixes: e54bcde3d69d ("arm64: eBPF JIT compiler") > Signed-off-by: Xi Wang <xi.wang@gmail.com>
Thanks. Applied.
-- Catalin
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