The bug fix was incomplete, it "replaced" crash with a memory leak.
The old code had an assignment to "ret" embedded into the conditional,
restore this.
Fixes: 7997eff828 ("netfilter: ebtables: reject blobs that don't provide all entry points")
Reported-and-tested-by: syzbot+a24c5252f3e3ab733464@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
The IPv6 path already drops dst in the daddr changed case, but the IPv4
path does not. This change makes the two code paths consistent.
Further, it is possible that there is already a metadata_dst allocated from
ingress that might already be attached to skbuff->dst while following
the bridge path. If it is not released before setting a new
metadata_dst, it will be leaked. This is similar to what is done in
bpf_set_tunnel_key() or ip6_route_input().
It is important to note that the memory being leaked is not the dst
being set in the bridge code, but rather memory allocated from some
other code path that is not being freed correctly before the skb dst is
overwritten.
An example of the leakage fixed by this commit found using kmemleak:
unreferenced object 0xffff888010112b00 (size 256):
comm "softirq", pid 0, jiffies 4294762496 (age 32.012s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 80 16 f1 83 ff ff ff ff ................
e1 4e f6 82 ff ff ff ff 00 00 00 00 00 00 00 00 .N..............
backtrace:
[<00000000d79567ea>] metadata_dst_alloc+0x1b/0xe0
[<00000000be113e13>] udp_tun_rx_dst+0x174/0x1f0
[<00000000a36848f4>] geneve_udp_encap_recv+0x350/0x7b0
[<00000000d4afb476>] udp_queue_rcv_one_skb+0x380/0x560
[<00000000ac064aea>] udp_unicast_rcv_skb+0x75/0x90
[<000000009a8ee8c5>] ip_protocol_deliver_rcu+0xd8/0x230
[<00000000ef4980bb>] ip_local_deliver_finish+0x7a/0xa0
[<00000000d7533c8c>] __netif_receive_skb_one_core+0x89/0xa0
[<00000000a879497d>] process_backlog+0x93/0x190
[<00000000e41ade9f>] __napi_poll+0x28/0x170
[<00000000b4c0906b>] net_rx_action+0x14f/0x2a0
[<00000000b20dd5d4>] __do_softirq+0xf4/0x305
[<000000003a7d7e15>] __irq_exit_rcu+0xc3/0x140
[<00000000968d39a2>] sysvec_apic_timer_interrupt+0x9e/0xc0
[<000000009e920794>] asm_sysvec_apic_timer_interrupt+0x16/0x20
[<000000008942add0>] native_safe_halt+0x13/0x20
Florian Westphal says: "Original code was likely fine because nothing
ever did set a skb->dst entry earlier than bridge in those days."
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Harsh Modi <harshmodi@google.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Harshit Mogalapalli says:
In ebt_do_table() function dereferencing 'private->hook_entry[hook]'
can lead to NULL pointer dereference. [..] Kernel panic:
general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
[..]
RIP: 0010:ebt_do_table+0x1dc/0x1ce0
Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5c 16 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 6c df 08 48 8d 7d 2c 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 88
[..]
Call Trace:
nf_hook_slow+0xb1/0x170
__br_forward+0x289/0x730
maybe_deliver+0x24b/0x380
br_flood+0xc6/0x390
br_dev_xmit+0xa2e/0x12c0
For some reason ebtables rejects blobs that provide entry points that are
not supported by the table, but what it should instead reject is the
opposite: blobs that DO NOT provide an entry point supported by the table.
t->valid_hooks is the bitmask of hooks (input, forward ...) that will see
packets. Providing an entry point that is not support is harmless
(never called/used), but the inverse isn't: it results in a crash
because the ebtables traverser doesn't expect a NULL blob for a location
its receiving packets for.
Instead of fixing all the individual checks, do what iptables is doing and
reject all blobs that differ from the expected hooks.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
After commit b6c02ef549 ("bridge: Netlink interface fix."),
br_fill_ifinfo() started to send an empty IFLA_AF_SPEC attribute when a
bridge vlan dump is requested but an interface does not have any vlans
configured.
iproute2 ignores such an empty attribute since commit b262a9becbcb
("bridge: Fix output with empty vlan lists") but older iproute2 versions as
well as other utilities have their output changed by the cited kernel
commit, resulting in failed test cases. Regardless, emitting an empty
attribute is pointless and inefficient.
Avoid this change by canceling the attribute if no AF_SPEC data was added.
Fixes: b6c02ef549 ("bridge: Netlink interface fix.")
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20220725001236.95062-1-bpoirier@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Same as the existing ones, no conversions. This is just for sparse sake
only so that we no longer mix be16/u16 and be32/u32 types.
Alternative is to add __force __beX in various places, but this
seems nicer.
objdiff shows no changes.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
drivers/net/ethernet/microchip/sparx5/sparx5_switchdev.c
9c5de246c1 ("net: sparx5: mdb add/del handle non-sparx5 devices")
fbb89d02e3 ("net: sparx5: Allow mdb entries to both CPU and ports")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When br_netfilter module is loaded, skbs may be diverted to the
ipv4/ipv6 hooks, just like as if we were routing.
Unfortunately, bridge filter hooks with priority 0 may be skipped
in this case.
Example:
1. an nftables bridge ruleset is loaded, with a prerouting
hook that has priority 0.
2. interface is added to the bridge.
3. no tcp packet is ever seen by the bridge prerouting hook.
4. flush the ruleset
5. load the bridge ruleset again.
6. tcp packets are processed as expected.
After 1) the only registered hook is the bridge prerouting hook, but its
not called yet because the bridge hasn't been brought up yet.
After 2), hook order is:
0 br_nf_pre_routing // br_netfilter internal hook
0 chain bridge f prerouting // nftables bridge ruleset
The packet is diverted to br_nf_pre_routing.
If call-iptables is off, the nftables bridge ruleset is called as expected.
But if its enabled, br_nf_hook_thresh() will skip it because it assumes
that all 0-priority hooks had been called previously in bridge context.
To avoid this, check for the br_nf_pre_routing hook itself, we need to
resume directly after it, even if this hook has a priority of 0.
Unfortunately, this still results in different packet flow.
With this fix, the eval order after in 3) is:
1. br_nf_pre_routing
2. ip(6)tables (if enabled)
3. nftables bridge
but after 5 its the much saner:
1. nftables bridge
2. br_nf_pre_routing
3. ip(6)tables (if enabled)
Unfortunately I don't see a solution here:
It would be possible to move br_nf_pre_routing to a higher priority
so that it will be called later in the pipeline, but this also impacts
ebtables evaluation order, and would still result in this very ordering
problem for all nftables-bridge hooks with the same priority as the
br_nf_pre_routing one.
Searching back through the git history I don't think this has
ever behaved in any other way, hence, no fixes-tag.
Reported-by: Radim Hrazdil <rhrazdil@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Adding mdb entries on disabled ports allows you to do setup before
accepting any traffic, avoiding any time where the port is not in the
multicast group.
Signed-off-by: Casper Andersson <casper.casan@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
As explained in commit 316580b69d ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
It is possible to stack bridges on top of each other. Consider the
following which makes use of an Ethernet switch:
br1
/ \
/ \
/ \
br0.11 wlan0
|
br0
/ | \
p1 p2 p3
br0 is offloaded to the switch. Above br0 is a vlan interface, for
vlan 11. This vlan interface is then a slave of br1. br1 also has a
wireless interface as a slave. This setup trunks wireless lan traffic
over the copper network inside a VLAN.
A frame received on p1 which is passed up to the bridge has the
skb->offload_fwd_mark flag set to true, indicating that the switch has
dealt with forwarding the frame out ports p2 and p3 as needed. This
flag instructs the software bridge it does not need to pass the frame
back down again. However, the flag is not getting reset when the frame
is passed upwards. As a result br1 sees the flag, wrongly interprets
it, and fails to forward the frame to wlan0.
When passing a frame upwards, clear the flag. This is the Rx
equivalent of br_switchdev_frame_unmark() in br_dev_xmit().
Fixes: f1c2eddf4c ("bridge: switchdev: Use an helper to clear forward mark")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20220518005840.771575-1-andrew@lunn.ch
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Drivers should call the TSO setting helper, GSO is controllable
by user space.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for fdb flush filtering based on destination ifindex and
vlan id. The ifindex must either match a port's device ifindex or the
bridge's. The vlan support is trivial since it's already validated by
rtnl_fdb_del, we just need to fill it in.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for fdb flush filtering based on ndm flags and state. NDM
state and flags are mapped to bridge-specific flags and matched
according to the specified masks. NTF_USE is used to represent
added_by_user flag since it sets it on fdb add and we don't have a 1:1
mapping for it. Only allowed bits can be set, NTF_SELF and NTF_MASTER are
ignored.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the ability to specify exactly which fdbs to be flushed. They are
described by a new structure - net_bridge_fdb_flush_desc. Currently it
can match on port/bridge ifindex, vlan id and fdb flags. It is used to
describe the existing dynamic fdb flush operation. Note that this flush
operation doesn't treat permanent entries in a special way (fdb_delete vs
fdb_delete_local), it will delete them regardless if any port is using
them, so currently it can't directly replace deletes which need to handle
that case, although we can extend it later for that too.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a minimal ndo_fdb_del_bulk implementation which flushes all entries.
Support for more fine-grained filtering will be added in the following
patches.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch expands on the earlier work on layer-2 mdb entries by adding
support for host entries. Due to the fact that host joined entries do
not have any flag field, we infer the permanent flag when reporting the
entries to userspace, which otherwise would be listed as 'temp'.
Before patch:
~# bridge mdb add dev br0 port br0 grp 01:00:00:c0:ff:ee permanent
Error: bridge: Flags are not allowed for host groups.
~# bridge mdb add dev br0 port br0 grp 01:00:00:c0:ff:ee
Error: bridge: Only permanent L2 entries allowed.
After patch:
~# bridge mdb add dev br0 port br0 grp 01:00:00:c0:ff:ee permanent
~# bridge mdb show
dev br0 port br0 grp 01:00:00:c0:ff:ee permanent vid 1
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add BR_HAIRPIN_MODE, BR_ISOLATED and BR_MULTICAST_TO_UNICAST port flags to
BR_PORT_FLAGS_HW_OFFLOAD so that switchdev drivers which have an offloaded
data plane have a chance to reject these bridge port flags if they don't
support them yet.
It makes the code path go through the
SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS driver handlers, which return
-EINVAL for everything they don't recognize.
For drivers that don't catch SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS at
all, switchdev will return -EOPNOTSUPP for those which is then ignored, but
those are in the minority.
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20220410134227.18810-1-arinc.unal@arinc9.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
