path: root/net/sched/cls_bpf.c
diff options
authorDaniel Borkmann <daniel@iogearbox.net>2018-01-17 22:36:49 +0100
committerDavid S. Miller <davem@davemloft.net>2018-01-17 17:14:06 -0500
commitad9294dbc227cbc8e173b3b963e7dd9af5314f77 (patch)
tree3f398c96a1d2930d88fe26da921d3aac697da99f /net/sched/cls_bpf.c
parentNet: ethernet: ti: netcp: Fix inbound ping crash if MTU size is greater than 1500 (diff)
bpf: fix cls_bpf on filter replace
Running the following sequence is currently broken: # tc qdisc add dev foo clsact # tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o # tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o RTNETLINK answers: Invalid argument The normal expectation on kernel side is that the second command succeeds replacing the existing program. However, what happens is in cls_bpf_change(), we bail out with err in the second run in cls_bpf_offload(). The EINVAL comes directly in cls_bpf_offload() when comparing prog vs oldprog's gen_flags. In case of above replace the new prog's gen_flags are 0, but the old ones are 8, which means TCA_CLS_FLAGS_NOT_IN_HW is set (e.g. drivers not having cls_bpf offload). Fix 102740bd9436 ("cls_bpf: fix offload assumptions after callback conversion") in the following way: gen_flags from user space passed down via netlink cannot include status flags like TCA_CLS_FLAGS_IN_HW or TCA_CLS_FLAGS_NOT_IN_HW as opposed to oldprog that we previously loaded. Therefore, it doesn't make any sense to include them in the gen_flags comparison with the new prog before we even attempt to offload. Thus, lets fix this before 4.15 goes out. Fixes: 102740bd9436 ("cls_bpf: fix offload assumptions after callback conversion") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/cls_bpf.c')
1 files changed, 8 insertions, 1 deletions
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 8d78e7f4ecc3..a62586e2dbdb 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -183,10 +183,17 @@ static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
return 0;
+static u32 cls_bpf_flags(u32 flags)
static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
struct cls_bpf_prog *oldprog)
- if (prog && oldprog && prog->gen_flags != oldprog->gen_flags)
+ if (prog && oldprog &&
+ cls_bpf_flags(prog->gen_flags) !=
+ cls_bpf_flags(oldprog->gen_flags))
return -EINVAL;
if (prog && tc_skip_hw(prog->gen_flags))