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authorDaniel Borkmann <daniel@iogearbox.net>2021-01-20 00:24:24 +0100
committerDaniel Borkmann <daniel@iogearbox.net>2021-01-20 17:19:40 +0100
commitbc895e8b2a64e502fbba72748d59618272052a8b (patch)
tree2f161e03d816093c3ee642a48cd920ab2a3288bf /kernel
parentb425e24a934e21a502d25089c6c7443d799c5594 (diff)
bpf: Fix signed_{sub,add32}_overflows type handling
Fix incorrect signed_{sub,add32}_overflows() input types (and a related buggy comment). It looks like this might have slipped in via copy/paste issue, also given prior to 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") the signature of signed_sub_overflows() had s64 a and s64 b as its input args whereas now they are truncated to s32. Thus restore proper types. Also, the case of signed_add32_overflows() is not consistent to signed_sub32_overflows(). Both have s32 as inputs, therefore align the former. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: De4dCr0w <sa516203@mail.ustc.edu.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/verifier.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 36af69fac591..e7368c5eacb7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5313,7 +5313,7 @@ static bool signed_add_overflows(s64 a, s64 b)
return res < a;
}
-static bool signed_add32_overflows(s64 a, s64 b)
+static bool signed_add32_overflows(s32 a, s32 b)
{
/* Do the add in u32, where overflow is well-defined */
s32 res = (s32)((u32)a + (u32)b);
@@ -5323,7 +5323,7 @@ static bool signed_add32_overflows(s64 a, s64 b)
return res < a;
}
-static bool signed_sub_overflows(s32 a, s32 b)
+static bool signed_sub_overflows(s64 a, s64 b)
{
/* Do the sub in u64, where overflow is well-defined */
s64 res = (s64)((u64)a - (u64)b);
@@ -5335,7 +5335,7 @@ static bool signed_sub_overflows(s32 a, s32 b)
static bool signed_sub32_overflows(s32 a, s32 b)
{
- /* Do the sub in u64, where overflow is well-defined */
+ /* Do the sub in u32, where overflow is well-defined */
s32 res = (s32)((u32)a - (u32)b);
if (b < 0)