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authorEdward Cree <ecree@solarflare.com>2018-11-16 12:00:07 +0000
committerAlexei Starovoitov <ast@kernel.org>2018-11-16 21:10:00 -0800
commitafd594240806acc138cf696c09f2f4829d55d02f (patch)
tree88202cf526afbabd2388e3eec49ade42e36c8457 /tools
parentda85d8bfd1512461bcfb64929e8426cf340b3707 (diff)
bpf: fix off-by-one error in adjust_subprog_starts
When patching in a new sequence for the first insn of a subprog, the start of that subprog does not change (it's the first insn of the sequence), so adjust_subprog_starts should check start <= off (rather than < off). Also added a test to test_verifier.c (it's essentially the syz reproducer). Fixes: cc8b0b92a169 ("bpf: introduce function calls (function boundaries)") Reported-by: syzbot+4fc427c7af994b0948be@syzkaller.appspotmail.com Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/bpf/test_verifier.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 6f61df62f690..550b7e46bf4a 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -13896,6 +13896,25 @@ static struct bpf_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
+ {
+ "calls: ctx read at start of subprog",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 5),
+ BPF_JMP_REG(BPF_JSGT, BPF_REG_0, BPF_REG_0, 0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_1, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
+ .errstr_unpriv = "function calls to other bpf functions are allowed for root only",
+ .result_unpriv = REJECT,
+ .result = ACCEPT,
+ },
};
static int probe_filter_length(const struct bpf_insn *fp)