From: Alexei Starovoitov <ast@kernel.org> stable inclusion from stable-5.10.80 commit 84dde8c8c9335213f091977eb1e935f3f38da71c bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit b9979db8340154526d9ab38a1883d6f6ba9b6d47 ] Before this fix: 166: (b5) if r2 <= 0x1 goto pc+22 from 166 to 189: R2=invP(id=1,umax_value=1,var_off=(0x0; 0xffffffff)) After this fix: 166: (b5) if r2 <= 0x1 goto pc+22 from 166 to 189: R2=invP(id=1,umax_value=1,var_off=(0x0; 0x1)) While processing BPF_JLE the reg_set_min_max() would set true_reg->umax_value = 1 and call __reg_combine_64_into_32(true_reg). Without the fix it would not pass the condition: if (__reg64_bound_u32(reg->umin_value) && __reg64_bound_u32(reg->umax_value)) since umin_value == 0 at this point. Before commit 10bf4e83167c the umin was incorrectly ingored. The commit 10bf4e83167c fixed the correctness issue, but pessimized propagation of 64-bit min max into 32-bit min max and corresponding var_off. Fixes: 10bf4e83167c ("bpf: Fix propagation of 32 bit unsigned bounds from 64 bit bounds") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211101222153.78759-1-alexei.starovoitov@gmail.... Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- kernel/bpf/verifier.c | 2 +- tools/testing/selftests/bpf/verifier/array_access.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4215c2ff6aeb..39542e270bb1 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1303,7 +1303,7 @@ static bool __reg64_bound_s32(s64 a) static bool __reg64_bound_u32(u64 a) { - return a > U32_MIN && a < U32_MAX; + return a >= U32_MIN && a <= U32_MAX; } static void __reg_combine_64_into_32(struct bpf_reg_state *reg) diff --git a/tools/testing/selftests/bpf/verifier/array_access.c b/tools/testing/selftests/bpf/verifier/array_access.c index 1b1c798e9248..1b138cd2b187 100644 --- a/tools/testing/selftests/bpf/verifier/array_access.c +++ b/tools/testing/selftests/bpf/verifier/array_access.c @@ -186,7 +186,7 @@ }, .fixup_map_hash_48b = { 3 }, .errstr_unpriv = "R0 leaks addr", - .errstr = "R0 unbounded memory access", + .errstr = "invalid access to map value, value_size=48 off=44 size=8", .result_unpriv = REJECT, .result = REJECT, .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, -- 2.20.1