lkml.org 
[lkml]   [2019]   [Jul]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.1 054/138] bpf: fix div64 overflow tests to properly detect errors
Date
[ 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,
--
2.20.1


\
 
 \ /
  Last update: 2019-07-12 14:40    [W:0.328 / U:6.420 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site