From: "Naveen N. Rao" naveen.n.rao@linux.vnet.ibm.com
[ Upstream commit 3e0682695199bad51dd898fe064d1564637ff77a ]
If the result of the division is LLONG_MIN, current tests do not detect the error since the return value is truncated to a 32-bit value and ends up being 0.
Signed-off-by: Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- .../testing/selftests/bpf/verifier/div_overflow.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/verifier/div_overflow.c b/tools/testing/selftests/bpf/verifier/div_overflow.c index bd3f38dbe796..acab4f00819f 100644 --- a/tools/testing/selftests/bpf/verifier/div_overflow.c +++ b/tools/testing/selftests/bpf/verifier/div_overflow.c @@ -29,8 +29,11 @@ "DIV64 overflow, check 1", .insns = { BPF_MOV64_IMM(BPF_REG_1, -1), - BPF_LD_IMM64(BPF_REG_0, LLONG_MIN), - BPF_ALU64_REG(BPF_DIV, BPF_REG_0, BPF_REG_1), + BPF_LD_IMM64(BPF_REG_2, LLONG_MIN), + BPF_ALU64_REG(BPF_DIV, BPF_REG_2, BPF_REG_1), + BPF_MOV32_IMM(BPF_REG_0, 0), + BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 1), + BPF_MOV32_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, .prog_type = BPF_PROG_TYPE_SCHED_CLS, @@ -40,8 +43,11 @@ { "DIV64 overflow, check 2", .insns = { - BPF_LD_IMM64(BPF_REG_0, LLONG_MIN), - BPF_ALU64_IMM(BPF_DIV, BPF_REG_0, -1), + BPF_LD_IMM64(BPF_REG_1, LLONG_MIN), + BPF_ALU64_IMM(BPF_DIV, BPF_REG_1, -1), + BPF_MOV32_IMM(BPF_REG_0, 0), + BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_1, 1), + BPF_MOV32_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, .prog_type = BPF_PROG_TYPE_SCHED_CLS,