diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2021-01-20 00:24:24 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-01-20 17:19:40 +0100 |
| commit | bc895e8b2a64e502fbba72748d59618272052a8b (patch) | |
| tree | 2f161e03d816093c3ee642a48cd920ab2a3288bf /kernel | |
| parent | b425e24a934e21a502d25089c6c7443d799c5594 (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.c | 6 |
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) |