From 4a50bc00847635e092f8f447439d8263afaa65ed Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 1 Nov 2021 15:21:52 -0700 Subject: [PATCH] bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit. [ Upstream commit 388e2c0b978339dee9b0a81a2e546f8979e021e2 ] Similar to unsigned bounds propagation fix signed bounds. The 'Fixes' tag is a hint. There is no security bug here. The verifier was too conservative. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20211101222153.78759-2-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin --- kernel/bpf/verifier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c56739a4a421..a15826a9a644 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1298,7 +1298,7 @@ static void __reg_combine_32_into_64(struct bpf_reg_state *reg) static bool __reg64_bound_s32(s64 a) { - return a > S32_MIN && a < S32_MAX; + return a >= S32_MIN && a <= S32_MAX; } static bool __reg64_bound_u32(u64 a)