diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-01-30 03:37:44 +0100 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@microsoft.com> | 2018-02-28 22:09:45 -0500 |
| commit | 754cfa993ace8a413fd5b34adec9226820bf03a6 (patch) | |
| tree | dc3d5e4f5891606f9c7c0c29ba6e8498be894bca /kernel | |
| parent | 31f1fa710257deb8eb3ec5236fd13562ec39dd22 (diff) | |
bpf: fix divides by zero
[ Upstream commit c366287ebd698ef5e3de300d90cd62ee9ee7373e ]
Divides by zero are not nice, lets avoid them if possible.
Also do_div() seems not needed when dealing with 32bit operands,
but this seems a minor detail.
Fixes: bd4cf0ed331a ("net: filter: rework/optimize internal BPF interpreter's instruction set")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 54f0e7fcd0e2..199b54e75359 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -361,7 +361,7 @@ select_insn: DST = tmp; CONT; ALU_MOD_X: - if (unlikely(SRC == 0)) + if (unlikely((u32)SRC == 0)) return 0; tmp = (u32) DST; DST = do_div(tmp, (u32) SRC); @@ -380,7 +380,7 @@ select_insn: DST = div64_u64(DST, SRC); CONT; ALU_DIV_X: - if (unlikely(SRC == 0)) + if (unlikely((u32)SRC == 0)) return 0; tmp = (u32) DST; do_div(tmp, (u32) SRC); |