From 1f9ab38f8a155913c9a587a673e61eedb75c9bc8 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Mon, 7 Aug 2017 15:29:11 +0100 Subject: [PATCH] selftests/bpf: don't try to access past MAX_PACKET_OFF in test_verifier A number of selftests fell foul of the changed MAX_PACKET_OFF handling. For instance, "direct packet access: test2" was potentially reading four bytes from pkt + 0xffff, which could take it past the verifier's limit, causing the program to be rejected (checks against pkt_end didn't give us any reg->range). Increase the shifts by one so that R2 is now mask 0x7fff instead of mask 0xffff. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/test_verifier.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 06914941f376..876b8785fd83 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -2330,8 +2330,8 @@ static struct bpf_test tests[] = { offsetof(struct __sk_buff, data)), BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_4), BPF_MOV64_REG(BPF_REG_2, BPF_REG_1), - BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 48), - BPF_ALU64_IMM(BPF_RSH, BPF_REG_2, 48), + BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 49), + BPF_ALU64_IMM(BPF_RSH, BPF_REG_2, 49), BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_2), BPF_MOV64_REG(BPF_REG_2, BPF_REG_3), BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 8), @@ -2710,11 +2710,11 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 0xffffffff), BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8), BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8), - BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffff), + BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0x7fff), BPF_MOV64_REG(BPF_REG_4, BPF_REG_0), BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2), BPF_MOV64_REG(BPF_REG_5, BPF_REG_4), - BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 0xffff - 1), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 0x7fff - 1), BPF_JMP_REG(BPF_JGT, BPF_REG_4, BPF_REG_3, 1), BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0), BPF_MOV64_IMM(BPF_REG_0, 0), @@ -2736,10 +2736,10 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_4, 0xffffffff), BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -8), BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -8), - BPF_ALU64_IMM(BPF_AND, BPF_REG_4, 0xffff), + BPF_ALU64_IMM(BPF_AND, BPF_REG_4, 0x7fff), BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2), BPF_MOV64_REG(BPF_REG_5, BPF_REG_4), - BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 0xffff - 1), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 0x7fff - 1), BPF_JMP_REG(BPF_JGT, BPF_REG_4, BPF_REG_3, 1), BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0), BPF_MOV64_IMM(BPF_REG_0, 0), @@ -2765,7 +2765,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_4, 0xffffffff), BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_4, -8), BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -8), - BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 48), + BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 49), BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2), BPF_MOV64_REG(BPF_REG_0, BPF_REG_4), BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 2), @@ -2820,7 +2820,7 @@ static struct bpf_test tests[] = { BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_4), BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_2), BPF_MOV64_REG(BPF_REG_5, BPF_REG_0), - BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 0xffff - 1), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 0x7fff - 1), BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1), BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_0, 0), BPF_MOV64_IMM(BPF_REG_0, 0), -- 2.20.1