diff options
| author | Cong Wang <cong.wang@bytedance.com> | 2022-12-17 14:17:07 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-07 12:07:30 +0100 |
| commit | 4d5d13eac3d73fab048c4c1cdcc3bcf4387d2a40 (patch) | |
| tree | 88193f5f4508b96cbc63278d3e070ad41579cb0c | |
| parent | ff3743d00f41d803e6ab9334962b674f3b7fd0cb (diff) | |
net_sched: reject TCF_EM_SIMPLE case for complex ematch module
[ Upstream commit 9cd3fd2054c3b3055163accbf2f31a4426f10317 ]
When TCF_EM_SIMPLE was introduced, it is supposed to be convenient
for ematch implementation:
https://lore.kernel.org/all/20050105110048.GO26856@postel.suug.ch/
"You don't have to, providing a 32bit data chunk without TCF_EM_SIMPLE
set will simply result in allocating & copy. It's an optimization,
nothing more."
So if an ematch module provides ops->datalen that means it wants a
complex data structure (saved in its em->data) instead of a simple u32
value. We should simply reject such a combination, otherwise this u32
could be misinterpreted as a pointer.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+4caeae4c7103813598ae@syzkaller.appspotmail.com
Reported-by: Jun Nie <jun.nie@linaro.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/sched/ematch.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/sched/ematch.c b/net/sched/ematch.c index d4d6f9c91e8c..59340d633253 100644 --- a/net/sched/ematch.c +++ b/net/sched/ematch.c @@ -259,6 +259,8 @@ static int tcf_em_validate(struct tcf_proto *tp, * the value carried. */ if (em_hdr->flags & TCF_EM_SIMPLE) { + if (em->ops->datalen > 0) + goto errout; if (data_len < sizeof(u32)) goto errout; em->data = *(u32 *) data; |