Commit Graph

4024 Commits (f9db1fc56281b96fe8748632b3894de970a8a850)

Author SHA1 Message Date
William Liu 0e1d5d9b5c net/sched: Return NULL when htb_lookup_leaf encounters an empty rbtree
htb_lookup_leaf has a BUG_ON that can trigger with the following:

tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: htb default 1
tc class add dev lo parent 1: classid 1:1 htb rate 64bit
tc qdisc add dev lo parent 1:1 handle 2: netem
tc qdisc add dev lo parent 2:1 handle 3: blackhole
ping -I lo -c1 -W0.001 127.0.0.1

The root cause is the following:

1. htb_dequeue calls htb_dequeue_tree which calls the dequeue handler on
   the selected leaf qdisc
2. netem_dequeue calls enqueue on the child qdisc
3. blackhole_enqueue drops the packet and returns a value that is not
   just NET_XMIT_SUCCESS
4. Because of this, netem_dequeue calls qdisc_tree_reduce_backlog, and
   since qlen is now 0, it calls htb_qlen_notify -> htb_deactivate ->
   htb_deactiviate_prios -> htb_remove_class_from_row -> htb_safe_rb_erase
5. As this is the only class in the selected hprio rbtree,
   __rb_change_child in __rb_erase_augmented sets the rb_root pointer to
   NULL
6. Because blackhole_dequeue returns NULL, netem_dequeue returns NULL,
   which causes htb_dequeue_tree to call htb_lookup_leaf with the same
   hprio rbtree, and fail the BUG_ON

The function graph for this scenario is shown here:
 0)               |  htb_enqueue() {
 0) + 13.635 us   |    netem_enqueue();
 0)   4.719 us    |    htb_activate_prios();
 0) # 2249.199 us |  }
 0)               |  htb_dequeue() {
 0)   2.355 us    |    htb_lookup_leaf();
 0)               |    netem_dequeue() {
 0) + 11.061 us   |      blackhole_enqueue();
 0)               |      qdisc_tree_reduce_backlog() {
 0)               |        qdisc_lookup_rcu() {
 0)   1.873 us    |          qdisc_match_from_root();
 0)   6.292 us    |        }
 0)   1.894 us    |        htb_search();
 0)               |        htb_qlen_notify() {
 0)   2.655 us    |          htb_deactivate_prios();
 0)   6.933 us    |        }
 0) + 25.227 us   |      }
 0)   1.983 us    |      blackhole_dequeue();
 0) + 86.553 us   |    }
 0) # 2932.761 us |    qdisc_warn_nonwc();
 0)               |    htb_lookup_leaf() {
 0)               |      BUG_ON();
 ------------------------------------------

The full original bug report can be seen here [1].

We can fix this just by returning NULL instead of the BUG_ON,
as htb_dequeue_tree returns NULL when htb_lookup_leaf returns
NULL.

[1] https://lore.kernel.org/netdev/pF5XOOIim0IuEfhI-SOxTgRvNoDwuux7UHKnE_Y5-zVd4wmGvNk2ceHjKb8ORnzw0cGwfmVu42g9dL7XyJLf1NEzaztboTWcm0Ogxuojoeo=@willsroot.io/

Fixes: 512bb43eb5 ("pkt_sched: sch_htb: Optimize WARN_ONs in htb_dequeue_tree() etc.")
Signed-off-by: William Liu <will@willsroot.io>
Signed-off-by: Savino Dicanosa <savy@syst3mfailure.io>
Link: https://patch.msgid.link/20250717022816.221364-1-will@willsroot.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17 07:47:55 -07:00
Xiang Mei 5e28d5a3f7 net/sched: sch_qfq: Fix race condition on qfq_aggregate
A race condition can occur when 'agg' is modified in qfq_change_agg
(called during qfq_enqueue) while other threads access it
concurrently. For example, qfq_dump_class may trigger a NULL
dereference, and qfq_delete_class may cause a use-after-free.

This patch addresses the issue by:

1. Moved qfq_destroy_class into the critical section.

2. Added sch_tree_lock protection to qfq_dump_class and
qfq_dump_class_stats.

Fixes: 462dbc9101 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-07-13 00:09:33 +01:00
Xiang Mei dd831ac822 net/sched: sch_qfq: Fix null-deref in agg_dequeue
To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c)
when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return
value before using it, similar to the existing approach in sch_hfsc.c.

To avoid code duplication, the following changes are made:

1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static
inline function.

2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to
include/net/pkt_sched.h so that sch_qfq can reuse it.

3. Applied qdisc_peek_len in agg_dequeue to avoid crashing.

Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://patch.msgid.link/20250705212143.3982664-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-07-10 11:08:35 +02:00
Victor Nogueira ffdde7bf5a net/sched: Abort __tc_modify_qdisc if parent class does not exist
Lion's patch [1] revealed an ancient bug in the qdisc API.
Whenever a user creates/modifies a qdisc specifying as a parent another
qdisc, the qdisc API will, during grafting, detect that the user is
not trying to attach to a class and reject. However grafting is
performed after qdisc_create (and thus the qdiscs' init callback) is
executed. In qdiscs that eventually call qdisc_tree_reduce_backlog
during init or change (such as fq, hhf, choke, etc), an issue
arises. For example, executing the following commands:

sudo tc qdisc add dev lo root handle a: htb default 2
sudo tc qdisc add dev lo parent a: handle beef fq

Qdiscs such as fq, hhf, choke, etc unconditionally invoke
qdisc_tree_reduce_backlog() in their control path init() or change() which
then causes a failure to find the child class; however, that does not stop
the unconditional invocation of the assumed child qdisc's qlen_notify with
a null class. All these qdiscs make the assumption that class is non-null.

The solution is ensure that qdisc_leaf() which looks up the parent
class, and is invoked prior to qdisc_create(), should return failure on
not finding the class.
In this patch, we leverage qdisc_leaf to return ERR_PTRs whenever the
parentid doesn't correspond to a class, so that we can detect it
earlier on and abort before qdisc_create is called.

[1] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/

Fixes: 5e50da01d0 ("[NET_SCHED]: Fix endless loops (part 2): "simple" qdiscs")
Reported-by: syzbot+d8b58d7b0ad89a678a16@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68663c93.a70a0220.5d25f.0857.GAE@google.com/
Reported-by: syzbot+5eccb463fa89309d8bdc@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68663c94.a70a0220.5d25f.0858.GAE@google.com/
Reported-by: syzbot+1261670bbdefc5485a06@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0013.GAE@google.com/
Reported-by: syzbot+15b96fc3aac35468fe77@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0014.GAE@google.com/
Reported-by: syzbot+4dadc5aecf80324d5a51@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68679e81.a70a0220.29cf51.0016.GAE@google.com/
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250707210801.372995-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-09 19:23:25 -07:00
Lion Ackermann 103406b38c net/sched: Always pass notifications when child class becomes empty
Certain classful qdiscs may invoke their classes' dequeue handler on an
enqueue operation. This may unexpectedly empty the child qdisc and thus
make an in-flight class passive via qlen_notify(). Most qdiscs do not
expect such behaviour at this point in time and may re-activate the
class eventually anyways which will lead to a use-after-free.

The referenced fix commit attempted to fix this behavior for the HFSC
case by moving the backlog accounting around, though this turned out to
be incomplete since the parent's parent may run into the issue too.
The following reproducer demonstrates this use-after-free:

    tc qdisc add dev lo root handle 1: drr
    tc filter add dev lo parent 1: basic classid 1:1
    tc class add dev lo parent 1: classid 1:1 drr
    tc qdisc add dev lo parent 1:1 handle 2: hfsc def 1
    tc class add dev lo parent 2: classid 2:1 hfsc rt m1 8 d 1 m2 0
    tc qdisc add dev lo parent 2:1 handle 3: netem
    tc qdisc add dev lo parent 3:1 handle 4: blackhole

    echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888
    tc class delete dev lo classid 1:1
    echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888

Since backlog accounting issues leading to a use-after-frees on stale
class pointers is a recurring pattern at this point, this patch takes
a different approach. Instead of trying to fix the accounting, the patch
ensures that qdisc_tree_reduce_backlog always calls qlen_notify when
the child qdisc is empty. This solves the problem because deletion of
qdiscs always involves a call to qdisc_reset() and / or
qdisc_purge_queue() which ultimately resets its qlen to 0 thus causing
the following qdisc_tree_reduce_backlog() to report to the parent. Note
that this may call qlen_notify on passive classes multiple times. This
is not a problem after the recent patch series that made all the
classful qdiscs qlen_notify() handlers idempotent.

Fixes: 3f98113810 ("sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()")
Signed-off-by: Lion Ackermann <nnamrec@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02 14:42:17 -07:00
Hyunwoo Kim b160766e26 net/sched: fix use-after-free in taprio_dev_notifier
Since taprio’s taprio_dev_notifier() isn’t protected by an
RCU read-side critical section, a race with advance_sched()
can lead to a use-after-free.

Adding rcu_read_lock() inside taprio_dev_notifier() prevents this.

Fixes: fed87cc671 ("net/sched: taprio: automatically calculate queueMaxSDU based on TC gate durations")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/aEzIYYxt0is9upYG@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-17 16:14:04 -07:00
Linus Torvalds 27605c8c0f Including fixes from bluetooth and wireless.
Current release - regressions:
 
  - af_unix: allow passing cred for embryo without SO_PASSCRED/SO_PASSPIDFD
 
 Current release - new code bugs:
 
  - eth: airoha: correct enable mask for RX queues 16-31
 
  - veth: prevent NULL pointer dereference in veth_xdp_rcv when peer
    disappears under traffic
 
  - ipv6: move fib6_config_validate() to ip6_route_add(), prevent invalid
    routes
 
 Previous releases - regressions:
 
  - phy: phy_caps: don't skip better duplex match on non-exact match
 
  - dsa: b53: fix untagged traffic sent via cpu tagged with VID 0
 
  - Revert "wifi: mwifiex: Fix HT40 bandwidth issue.", it caused transient
    packet loss, exact reason not fully understood, yet
 
 Previous releases - always broken:
 
  - net: clear the dst when BPF is changing skb protocol (IPv4 <> IPv6)
 
  - sched: sfq: fix a potential crash on gso_skb handling
 
  - Bluetooth: intel: improve rx buffer posting to avoid causing issues
    in the firmware
 
  - eth: intel: i40e: make reset handling robust against multiple requests
 
  - eth: mlx5: ensure FW pages are always allocated on the local NUMA
    node, even when device is configure to 'serve' another node
 
  - wifi: ath12k: fix GCC_GCC_PCIE_HOT_RST definition for WCN7850,
    prevent kernel crashes
 
  - wifi: ath11k: avoid burning CPU in ath11k_debugfs_fw_stats_request()
    for 3 sec if fw_stats_done is not set
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bluetooth and wireless.

  Current release - regressions:

   - af_unix: allow passing cred for embryo without SO_PASSCRED/SO_PASSPIDFD

  Current release - new code bugs:

   - eth: airoha: correct enable mask for RX queues 16-31

   - veth: prevent NULL pointer dereference in veth_xdp_rcv when peer
     disappears under traffic

   - ipv6: move fib6_config_validate() to ip6_route_add(), prevent
     invalid routes

  Previous releases - regressions:

   - phy: phy_caps: don't skip better duplex match on non-exact match

   - dsa: b53: fix untagged traffic sent via cpu tagged with VID 0

   - Revert "wifi: mwifiex: Fix HT40 bandwidth issue.", it caused
     transient packet loss, exact reason not fully understood, yet

  Previous releases - always broken:

   - net: clear the dst when BPF is changing skb protocol (IPv4 <> IPv6)

   - sched: sfq: fix a potential crash on gso_skb handling

   - Bluetooth: intel: improve rx buffer posting to avoid causing issues
     in the firmware

   - eth: intel: i40e: make reset handling robust against multiple
     requests

   - eth: mlx5: ensure FW pages are always allocated on the local NUMA
     node, even when device is configure to 'serve' another node

   - wifi: ath12k: fix GCC_GCC_PCIE_HOT_RST definition for WCN7850,
     prevent kernel crashes

   - wifi: ath11k: avoid burning CPU in ath11k_debugfs_fw_stats_request()
     for 3 sec if fw_stats_done is not set"

* tag 'net-6.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (70 commits)
  selftests: drv-net: rss_ctx: Add test for ntuple rules targeting default RSS context
  net: ethtool: Don't check if RSS context exists in case of context 0
  af_unix: Allow passing cred for embryo without SO_PASSCRED/SO_PASSPIDFD.
  ipv6: Move fib6_config_validate() to ip6_route_add().
  net: drv: netdevsim: don't napi_complete() from netpoll
  net/mlx5: HWS, Add error checking to hws_bwc_rule_complex_hash_node_get()
  veth: prevent NULL pointer dereference in veth_xdp_rcv
  net_sched: remove qdisc_tree_flush_backlog()
  net_sched: ets: fix a race in ets_qdisc_change()
  net_sched: tbf: fix a race in tbf_change()
  net_sched: red: fix a race in __red_change()
  net_sched: prio: fix a race in prio_tune()
  net_sched: sch_sfq: reject invalid perturb period
  net: phy: phy_caps: Don't skip better duplex macth on non-exact match
  MAINTAINERS: Update Kuniyuki Iwashima's email address.
  selftests: net: add test case for NAT46 looping back dst
  net: clear the dst when changing skb protocol
  net/mlx5e: Fix number of lanes to UNKNOWN when using data_rate_oper
  net/mlx5e: Fix leak of Geneve TLV option object
  net/mlx5: HWS, make sure the uplink is the last destination
  ...
2025-06-12 09:50:36 -07:00
Eric Dumazet d92adacdd8 net_sched: ets: fix a race in ets_qdisc_change()
Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer
fires at the wrong time.

The race is as follows:

CPU 0                                 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
 |
 |                                    [5]: lock root
 |                                    [6]: rehash
 |                                    [7]: qdisc_tree_reduce_backlog()
 |
[4]: qdisc_put()

This can be abused to underflow a parent's qlen.

Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.

Fixes: b05972f01e ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12 08:05:50 -07:00
Eric Dumazet 43eb466041 net_sched: tbf: fix a race in tbf_change()
Gerrard Tai reported a race condition in TBF, whenever SFQ perturb timer
fires at the wrong time.

The race is as follows:

CPU 0                                 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
 |
 |                                    [5]: lock root
 |                                    [6]: rehash
 |                                    [7]: qdisc_tree_reduce_backlog()
 |
[4]: qdisc_put()

This can be abused to underflow a parent's qlen.

Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.

Fixes: b05972f01e ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://patch.msgid.link/20250611111515.1983366-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12 08:05:50 -07:00
Eric Dumazet 85a3e0ede3 net_sched: red: fix a race in __red_change()
Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer
fires at the wrong time.

The race is as follows:

CPU 0                                 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
 |
 |                                    [5]: lock root
 |                                    [6]: rehash
 |                                    [7]: qdisc_tree_reduce_backlog()
 |
[4]: qdisc_put()

This can be abused to underflow a parent's qlen.

Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.

Fixes: 0c8d13ac96 ("net: sched: red: delay destroying child qdisc on replace")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12 08:05:49 -07:00
Eric Dumazet d35acc1be3 net_sched: prio: fix a race in prio_tune()
Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.

The race is as follows:

CPU 0                                 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
 |
 |                                    [5]: lock root
 |                                    [6]: rehash
 |                                    [7]: qdisc_tree_reduce_backlog()
 |
[4]: qdisc_put()

This can be abused to underflow a parent's qlen.

Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.

Fixes: 7b8e0b6e65 ("net: sched: prio: delay destroying child qdiscs on change")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12 08:05:49 -07:00
Eric Dumazet 7ca52541c0 net_sched: sch_sfq: reject invalid perturb period
Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch.

We want to make sure ctl->perturb_period * HZ will not overflow
and is positive.

Tested:

tc qd add dev lo root sfq perturb -10   # negative value : error
Error: sch_sfq: invalid perturb period.

tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period.

tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12 08:03:08 -07:00
Eric Dumazet 82ffbe7776 net_sched: sch_sfq: fix a potential crash on gso_skb handling
SFQ has an assumption of always being able to queue at least one packet.

However, after the blamed commit, sch->q.len can be inflated by packets
in sch->gso_skb, and an enqueue() on an empty SFQ qdisc can be followed
by an immediate drop.

Fix sfq_drop() to properly clear q->tail in this situation.

Tested:

ip netns add lb
ip link add dev to-lb type veth peer name in-lb netns lb
ethtool -K to-lb tso off                 # force qdisc to requeue gso_skb
ip netns exec lb ethtool -K in-lb gro on # enable NAPI
ip link set dev to-lb up
ip -netns lb link set dev in-lb up
ip addr add dev to-lb 192.168.20.1/24
ip -netns lb addr add dev in-lb 192.168.20.2/24
tc qdisc replace dev to-lb root sfq limit 100

ip netns exec lb netserver

netperf -H 192.168.20.2 -l 100 &
netperf -H 192.168.20.2 -l 100 &
netperf -H 192.168.20.2 -l 100 &
netperf -H 192.168.20.2 -l 100 &

Fixes: a53851e2c3 ("net: sched: explicit locking in gso_cpu fallback")
Reported-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
Closes: https://lore.kernel.org/netdev/9da42688-bfaa-4364-8797-e9271f3bdaef@hetzner-cloud.de/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250606165127.3629486-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-09 14:21:36 -07:00
Ingo Molnar 41cb08555c treewide, timers: Rename from_timer() to timer_container_of()
Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
2025-06-08 09:07:37 +02:00
Paolo Abeni f6bd8faeb1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes to prepare for the 6.16 net-next PR.

No conflicts nor adjacent changes.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-28 10:11:15 +02:00
Pedro Tammela ac9fe7dd8e net_sched: hfsc: Address reentrant enqueue adding class to eltree twice
Savino says:
    "We are writing to report that this recent patch
    (141d34391a) [1]
    can be bypassed, and a UAF can still occur when HFSC is utilized with
    NETEM.

    The patch only checks the cl->cl_nactive field to determine whether
    it is the first insertion or not [2], but this field is only
    incremented by init_vf [3].

    By using HFSC_RSC (which uses init_ed) [4], it is possible to bypass the
    check and insert the class twice in the eltree.
    Under normal conditions, this would lead to an infinite loop in
    hfsc_dequeue for the reasons we already explained in this report [5].

    However, if TBF is added as root qdisc and it is configured with a
    very low rate,
    it can be utilized to prevent packets from being dequeued.
    This behavior can be exploited to perform subsequent insertions in the
    HFSC eltree and cause a UAF."

To fix both the UAF and the infinite loop, with netem as an hfsc child,
check explicitly in hfsc_enqueue whether the class is already in the eltree
whenever the HFSC_RSC flag is set.

[1] https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=141d34391abbb315d68556b7c67ad97885407547
[2] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L1572
[3] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L677
[4] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L1574
[5] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/T/#u

Fixes: 37d9cf1a3c ("sched: Fix detection of empty queues in child qdiscs")
Reported-by: Savino Dicanosa <savy@syst3mfailure.io>
Reported-by: William Liu <will@willsroot.io>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Link: https://patch.msgid.link/20250522181448.1439717-2-pctammela@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-28 08:55:35 +02:00
Jakub Kicinski 33e1b1b399 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.15-rc8).

Conflicts:
  80f2ab46c2 ("irdma: free iwdev->rf after removing MSI-X")
  4bcc063939 ("ice, irdma: fix an off by one in error handling code")
  c24a65b6a2 ("iidc/ice/irdma: Update IDC to support multiple consumers")
https://lore.kernel.org/20250513130630.280ee6c5@canb.auug.org.au

No extra adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-22 09:42:41 -07:00
Cong Wang 3f98113810 sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()
When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the
child qdisc's peek() operation before incrementing sch->q.qlen and
sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may
trigger an immediate dequeue and potential packet drop. In such cases,
qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog
have not yet been updated, leading to inconsistent queue accounting. This
can leave an empty HFSC class in the active list, causing further
consequences like use-after-free.

This patch fixes the bug by moving the increment of sch->q.qlen and
sch->qstats.backlog before the call to the child qdisc's peek() operation.
This ensures that queue length and backlog are always accurate when packet
drops or dequeues are triggered during the peek.

Fixes: 12d0ad3be9 ("net/sched/sch_hfsc.c: handle corner cases where head may change invalidating calculated deadline")
Reported-by: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250518222038.58538-2-xiyou.wangcong@gmail.com
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-22 11:16:44 +02:00
Eric Biggers 99de9d4022 sctp: use skb_crc32c() instead of __skb_checksum()
Make sctp_compute_cksum() just use the new function skb_crc32c(),
instead of calling __skb_checksum() with a skb_checksum_ops struct that
does CRC32C.  This is faster and simpler.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20250519175012.36581-6-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-21 15:40:16 -07:00
Jakub Kicinski bebd7b2626 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.15-rc7).

Conflicts:

tools/testing/selftests/drivers/net/hw/ncdevmem.c
  97c4e094a4 ("tests/ncdevmem: Fix double-free of queue array")
  2f1a805f32 ("selftests: ncdevmem: Implement devmem TCP TX")
https://lore.kernel.org/20250514122900.1e77d62d@canb.auug.org.au

Adjacent changes:

net/core/devmem.c
net/core/devmem.h
  0afc44d8cd ("net: devmem: fix kernel panic when netlink socket close after module unload")
  bd61848900 ("net: devmem: Implement TX path")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-15 11:28:30 -07:00
Sebastian Andrzej Siewior 20d677d389 net/sched: Use nested-BH locking for sch_frag_data_storage
sch_frag_data_storage is a per-CPU variable and relies on disabled BH
for its locking. Without per-CPU locking in local_bh_disable() on
PREEMPT_RT this data structure requires explicit locking.

Add local_lock_t to the struct and use local_lock_nested_bh() for locking.
This change adds only lockdep coverage and does not alter the functional
behaviour for !PREEMPT_RT.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-12-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-15 15:23:31 +02:00
Sebastian Andrzej Siewior 7fe70c06a1 net/sched: act_mirred: Move the recursion counter struct netdev_xmit
mirred_nest_level is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT
this data structure requires explicit locking.

Move mirred_nest_level to struct netdev_xmit as u8, provide wrappers.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20250512092736.229935-11-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-15 15:23:31 +02:00
Cong Wang 2d3cbfd6d5 net_sched: Flush gso_skb list too during ->change()
Previously, when reducing a qdisc's limit via the ->change() operation, only
the main skb queue was trimmed, potentially leaving packets in the gso_skb
list. This could result in NULL pointer dereference when we only check
sch->limit against sch->q.qlen.

This patch introduces a new helper, qdisc_dequeue_internal(), which ensures
both the gso_skb list and the main queue are properly flushed when trimming
excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie)
are updated to use this helper in their ->change() routines.

Fixes: 76e3cc126b ("codel: Controlled Delay AQM")
Fixes: 4b549a2ef4 ("fq_codel: Fair Queue Codel AQM")
Fixes: afe4fd0624 ("pkt_sched: fq: Fair Queue packet scheduler")
Fixes: ec97ecf1eb ("net: sched: add Flow Queue PIE packet scheduler")
Fixes: 10239edf86 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc")
Fixes: d4b36210c2 ("net: pkt_sched: PIE AQM scheme")
Reported-by: Will <willsroot@protonmail.com>
Reported-by: Savy <savy@syst3mfailure.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-09 12:34:38 +01:00
Jakub Kicinski 6b02fd7799 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.15-rc6).

No conflicts.

Adjacent changes:

net/core/dev.c:
  08e9f2d584 ("net: Lock netdevices during dev_shutdown")
  a82dc19db1 ("net: avoid potential race between netdev_get_by_index_lock() and netns switch")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-08 08:59:02 -07:00
Cong Wang 3769478610 sch_htb: make htb_deactivate() idempotent
Alan reported a NULL pointer dereference in htb_next_rb_node()
after we made htb_qlen_notify() idempotent.

It turns out in the following case it introduced some regression:

htb_dequeue_tree():
  |-> fq_codel_dequeue()
    |-> qdisc_tree_reduce_backlog()
      |-> htb_qlen_notify()
        |-> htb_deactivate()
  |-> htb_next_rb_node()
  |-> htb_deactivate()

For htb_next_rb_node(), after calling the 1st htb_deactivate(), the
clprio[prio]->ptr could be already set to  NULL, which means
htb_next_rb_node() is vulnerable here.

For htb_deactivate(), although we checked qlen before calling it, in
case of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again
which triggers the warning inside.

To fix the issues here, we need to:

1) Make htb_deactivate() idempotent, that is, simply return if we
   already call it before.
2) Make htb_next_rb_node() safe against ptr==NULL.

Many thanks to Alan for testing and for the reproducer.

Fixes: 5ba8b837b5 ("sch_htb: make htb_qlen_notify() idempotent")
Reported-by: Alan J. Wylie <alan@wylie.me.uk>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://patch.msgid.link/20250428232955.1740419-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-05 13:51:32 -07:00
Jakub Kicinski b4cd2ee54c bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-05-02

We've added 14 non-merge commits during the last 10 day(s) which contain
a total of 13 files changed, 740 insertions(+), 121 deletions(-).

The main changes are:

1) Avoid skipping or repeating a sk when using a UDP bpf_iter,
   from Jordan Rife.

2) Fixed a crash when a bpf qdisc is set in
   the net.core.default_qdisc, from Amery Hung.

3) A few other fixes in the bpf qdisc, from Amery Hung.
   - Always call qdisc_watchdog_init() in the .init prologue such that
     the .reset/.destroy epilogue can always call qdisc_watchdog_cancel()
     without issue.
   - bpf_qdisc_init_prologue() was incorrectly returning an error
     when the bpf qdisc is set as the default_qdisc and the mq is creating
     the default_qdisc. It is now fixed.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Cleanup bpf qdisc selftests
  selftests/bpf: Test attaching a bpf qdisc with incomplete operators
  bpf: net_sched: Make some Qdisc_ops ops mandatory
  selftests/bpf: Test setting and creating bpf qdisc as default qdisc
  bpf: net_sched: Fix bpf qdisc init prologue when set as default qdisc
  selftests/bpf: Add tests for bucket resume logic in UDP socket iterators
  selftests/bpf: Return socket cookies from sock_iter_batch progs
  bpf: udp: Avoid socket skips and repeats during iteration
  bpf: udp: Use bpf_udp_iter_batch_item for bpf_udp_iter_state batch items
  bpf: udp: Get rid of st_bucket_done
  bpf: udp: Make sure iter->batch always contains a full bucket snapshot
  bpf: udp: Make mem flags configurable through bpf_iter_udp_realloc_batch
  bpf: net_sched: Fix using bpf qdisc as default qdisc
  selftests/bpf: Fix compilation errors
====================

Link: https://patch.msgid.link/20250503010755.4030524-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-05 13:22:58 -07:00
Amery Hung 64d6e3b9df bpf: net_sched: Make some Qdisc_ops ops mandatory
The patch makes all currently supported Qdisc_ops (i.e., .enqueue,
.dequeue, .init, .reset, and .destroy) mandatory.

Make .init, .reset and .destroy mandatory as bpf qdisc relies on prologue
and epilogue to check attach points and correctly initialize/cleanup
resources. The prologue/epilogue will only be generated for an struct_ops
operator only if users implement the operator.

Make .enqueue and .dequeue mandatory as bpf qdisc infra does not provide
a default data path.

Fixes: c824034495 ("bpf: net_sched: Support implementation of Qdisc_ops in bpf")
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2025-05-02 15:35:37 -07:00
Amery Hung 659b3b2c48 bpf: net_sched: Fix bpf qdisc init prologue when set as default qdisc
Allow .init to proceed if qdisc_lookup() returns NULL as it only happens
when called by qdisc_create_dflt() in mq/mqprio_init and the parent qdisc
has not been added to qdisc_hash yet. In qdisc_create(), the caller,
__tc_modify_qdisc(), would have made sure the parent qdisc already exist.

In addition, call qdisc_watchdog_init() whether .init succeeds or not to
prevent null-pointer dereference. In qdisc_create() and
qdisc_create_dflt(), if .init fails, .destroy will be called. As a
result, the destroy epilogue could call qdisc_watchdog_cancel() with an
uninitialized timer, causing null-pointer deference in hrtimer_cancel().

Fixes: c824034495 ("bpf: net_sched: Support implementation of Qdisc_ops in bpf")
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2025-05-02 14:50:08 -07:00
Jakub Kicinski 337079d31f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.15-rc5).

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-01 15:11:38 -07:00
Amery Hung 7625645e69 bpf: net_sched: Fix using bpf qdisc as default qdisc
Use bpf_try_module_get()/bpf_module_put() instead of try_module_get()/
module_put() when handling default qdisc since users can assign a bpf
qdisc to it.

To trigger the bug:
$ bpftool struct_ops register bpf_qdisc_fq.bpf.o /sys/fs/bpf
$ echo bpf_fq > /proc/sys/net/core/default_qdisc

Fixes: c824034495 ("bpf: net_sched: Support implementation of Qdisc_ops in bpf")
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250429192128.3860571-1-ameryhung@gmail.com
2025-04-29 14:25:41 -07:00
Victor Nogueira f139f37dcd net_sched: qfq: Fix double list add in class with netem as child qdisc
As described in Gerrard's report [1], there are use cases where a netem
child qdisc will make the parent qdisc's enqueue callback reentrant.
In the case of qfq, there won't be a UAF, but the code will add the same
classifier to the list twice, which will cause memory corruption.

This patch checks whether the class was already added to the agg->active
list (cl_is_active) before doing the addition to cater for the reentrant
case.

[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

Fixes: 37d9cf1a3c ("sched: Fix detection of empty queues in child qdiscs")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250425220710.3964791-5-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-28 15:55:07 -07:00
Victor Nogueira 1a6d0c00fa net_sched: ets: Fix double list add in class with netem as child qdisc
As described in Gerrard's report [1], there are use cases where a netem
child qdisc will make the parent qdisc's enqueue callback reentrant.
In the case of ets, there won't be a UAF, but the code will add the same
classifier to the list twice, which will cause memory corruption.

In addition to checking for qlen being zero, this patch checks whether
the class was already added to the active_list (cl_is_active) before
doing the addition to cater for the reentrant case.

[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

Fixes: 37d9cf1a3c ("sched: Fix detection of empty queues in child qdiscs")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250425220710.3964791-4-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-28 15:55:06 -07:00
Victor Nogueira 141d34391a net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc
As described in Gerrard's report [1], we have a UAF case when an hfsc class
has a netem child qdisc. The crux of the issue is that hfsc is assuming
that checking for cl->qdisc->q.qlen == 0 guarantees that it hasn't inserted
the class in the vttree or eltree (which is not true for the netem
duplicate case).

This patch checks the n_active class variable to make sure that the code
won't insert the class in the vttree or eltree twice, catering for the
reentrant case.

[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

Fixes: 37d9cf1a3c ("sched: Fix detection of empty queues in child qdiscs")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250425220710.3964791-3-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-28 15:55:06 -07:00
Victor Nogueira f99a3fbf02 net_sched: drr: Fix double list add in class with netem as child qdisc
As described in Gerrard's report [1], there are use cases where a netem
child qdisc will make the parent qdisc's enqueue callback reentrant.
In the case of drr, there won't be a UAF, but the code will add the same
classifier to the list twice, which will cause memory corruption.

In addition to checking for qlen being zero, this patch checks whether the
class was already added to the active_list (cl_is_active) before adding
to the list to cover for the reentrant case.

[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

Fixes: 37d9cf1a3c ("sched: Fix detection of empty queues in child qdiscs")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250425220710.3964791-2-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-28 15:55:06 -07:00
Jakub Kicinski 5565acd1e6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.15-rc4).

This pull includes wireless and a fix to vxlan which isn't
in Linus's tree just yet. The latter creates with a silent conflict
/ build breakage, so merging it now to avoid causing problems.

drivers/net/vxlan/vxlan_vnifilter.c
  094adad913 ("vxlan: Use a single lock to protect the FDB table")
  087a9eb9e5 ("vxlan: vnifilter: Fix unlocked deletion of default FDB entry")
https://lore.kernel.org/20250423145131.513029-1-idosch@nvidia.com

No "normal" conflicts, or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-24 11:20:52 -07:00
Cong Wang 6ccbda44e2 net_sched: hfsc: Fix a potential UAF in hfsc_dequeue() too
Similarly to the previous patch, we need to safe guard hfsc_dequeue()
too. But for this one, we don't have a reliable reproducer.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250417184732.943057-3-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-23 17:16:50 -07:00
Cong Wang 3df275ef0a net_sched: hfsc: Fix a UAF vulnerability in class handling
This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class
handling. The issue occurs due to a time-of-check/time-of-use condition
in hfsc_change_class() when working with certain child qdiscs like netem
or codel.

The vulnerability works as follows:
1. hfsc_change_class() checks if a class has packets (q.qlen != 0)
2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g.,
   codel, netem) might drop packets and empty the queue
3. The code continues assuming the queue is still non-empty, adding
   the class to vttree
4. This breaks HFSC scheduler assumptions that only non-empty classes
   are in vttree
5. Later, when the class is destroyed, this can lead to a Use-After-Free

The fix adds a second queue length check after qdisc_peek_len() to verify
the queue wasn't emptied.

Fixes: 21f4d5cc25 ("net_sched/hfsc: fix curve activation in hfsc_change_class()")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Reviewed-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250417184732.943057-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-23 17:16:50 -07:00
Jakub Kicinski 07e32237ed bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-04-17

We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 18 files changed, 1748 insertions(+), 19 deletions(-).

The main changes are:

1) bpf qdisc support, from Amery Hung.
   A qdisc can be implemented in bpf struct_ops programs and
   can be used the same as other existing qdiscs in the
   "tc qdisc" command.

2) Add xsk tail adjustment tests, from Tushar Vyavahare.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Test attaching bpf qdisc to mq and non root
  selftests/bpf: Add a bpf fq qdisc to selftest
  selftests/bpf: Add a basic fifo qdisc test
  libbpf: Support creating and destroying qdisc
  bpf: net_sched: Disable attaching bpf qdisc to non root
  bpf: net_sched: Support updating bstats
  bpf: net_sched: Add a qdisc watchdog timer
  bpf: net_sched: Add basic bpf qdisc kfuncs
  bpf: net_sched: Support implementation of Qdisc_ops in bpf
  bpf: Prepare to reuse get_ctx_arg_idx
  selftests/xsk: Add tail adjustment tests and support check
  selftests/xsk: Add packet stream replacement function
====================

Link: https://patch.msgid.link/20250417184338.3152168-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-21 18:51:08 -07:00
Amery Hung e582778f02 bpf: net_sched: Disable attaching bpf qdisc to non root
Do not allow users to attach bpf qdiscs to classful qdiscs. This is to
prevent accidentally breaking existings classful qdiscs if they rely on
some data in the child qdisc. This restriction can potentially be lifted
in the future. Note that, we still allow bpf qdisc to be attached to mq.

Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-7-ameryhung@gmail.com
2025-04-17 10:54:40 -07:00
Amery Hung 544e0a1f1e bpf: net_sched: Support updating bstats
Add a kfunc to update Qdisc bstats when an skb is dequeued. The kfunc is
only available in .dequeue programs.

Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-6-ameryhung@gmail.com
2025-04-17 10:54:40 -07:00
Amery Hung 7a2dafda95 bpf: net_sched: Add a qdisc watchdog timer
Add a watchdog timer to bpf qdisc. The watchdog can be used to schedule
the execution of qdisc through kfunc, bpf_qdisc_schedule(). It can be
useful for building traffic shaping scheduling algorithm, where the time
the next packet will be dequeued is known.

The implementation relies on struct_ops gen_prologue/epilogue to patch bpf
programs provided by users. Operator specific prologue/epilogue kfuncs
are introduced instead of watchdog kfuncs so that it is easier to extend
prologue/epilogue in the future (writing C vs BPF bytecode).

Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-5-ameryhung@gmail.com
2025-04-17 10:54:40 -07:00
Amery Hung 870c28588a bpf: net_sched: Add basic bpf qdisc kfuncs
Add basic kfuncs for working on skb in qdisc.

Both bpf_qdisc_skb_drop() and bpf_kfree_skb() can be used to release
a reference to an skb. However, bpf_qdisc_skb_drop() can only be called
in .enqueue where a to_free skb list is available from kernel to defer
the release. bpf_kfree_skb() should be used elsewhere. It is also used
in bpf_obj_free_fields() when cleaning up skb in maps and collections.

bpf_skb_get_hash() returns the flow hash of an skb, which can be used
to build flow-based queueing algorithms.

Finally, allow users to create read-only dynptr via bpf_dynptr_from_skb().

Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-4-ameryhung@gmail.com
2025-04-17 10:54:40 -07:00
Amery Hung c824034495 bpf: net_sched: Support implementation of Qdisc_ops in bpf
The recent advancement in bpf such as allocated objects, bpf list and bpf
rbtree has provided powerful and flexible building blocks to realize
sophisticated packet scheduling algorithms. As struct_ops now supports
core operators in Qdisc_ops, start allowing qdisc to be implemented using
bpf struct_ops with this patch. Users can implement Qdisc_ops.{enqueue,
dequeue, init, reset, destroy} in bpf and register the qdisc dynamically
into the kernel.

Co-developed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-3-ameryhung@gmail.com
2025-04-17 10:54:33 -07:00
Toke Høiland-Jørgensen 5f5f92912b tc: Return an error if filters try to attach too many actions
While developing the fix for the buffer sizing issue in [0], I noticed
that the kernel will happily accept a long list of actions for a filter,
and then just silently truncate that list down to a maximum of 32
actions.

That seems less than ideal, so this patch changes the action parsing to
return an error message and refuse to create the filter in this case.
This results in an error like:

 # ip link add type veth
 # tc qdisc replace dev veth0 root handle 1: fq_codel
 # tc -echo filter add dev veth0 parent 1: u32 match u32 0 0 $(for i in $(seq 33); do echo action pedit munge ip dport set 22; done)
Error: Only 32 actions supported per filter.
We have an error talking to the kernel

Instead of just creating a filter with 32 actions and dropping the last
one.

This is obviously a change in UAPI. But seeing as creating more than 32
filters has never actually *worked*, it seems that returning an explicit
error is better, and any use cases that get broken by this were already
broken just in more subtle ways.

[0] https://lore.kernel.org/r/20250407105542.16601-1-toke@redhat.com

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409145523.164506-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-15 17:13:11 -07:00
Linus Torvalds ab59a86056 Including fixes from netfilter.
Current release - regressions:
 
   - core: hold instance lock during NETDEV_CHANGE
 
   - rtnetlink: fix bad unlock balance in do_setlink().
 
   - ipv6:
     - fix null-ptr-deref in addrconf_add_ifaddr().
     - align behavior across nexthops during path selection
 
 Previous releases - regressions:
 
   - sctp: prevent transport UaF in sendmsg
 
   - mptcp: only inc MPJoinAckHMacFailure for HMAC failures
 
 Previous releases - always broken:
 
   - sched:
     - make ->qlen_notify() idempotent
     - ensure sufficient space when sending filter netlink notifications
     - sch_sfq: really don't allow 1 packet limit
 
   - netfilter: fix incorrect avx2 match of 5th field octet
 
   - tls: explicitly disallow disconnect
 
   - eth: octeontx2-pf: fix VF root node parent queue priority
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter.

  Current release - regressions:

    - core: hold instance lock during NETDEV_CHANGE

    - rtnetlink: fix bad unlock balance in do_setlink()

    - ipv6:
       - fix null-ptr-deref in addrconf_add_ifaddr()
       - align behavior across nexthops during path selection

  Previous releases - regressions:

    - sctp: prevent transport UaF in sendmsg

    - mptcp: only inc MPJoinAckHMacFailure for HMAC failures

  Previous releases - always broken:

    - sched:
       - make ->qlen_notify() idempotent
       - ensure sufficient space when sending filter netlink notifications
       - sch_sfq: really don't allow 1 packet limit

    - netfilter: fix incorrect avx2 match of 5th field octet

    - tls: explicitly disallow disconnect

    - eth: octeontx2-pf: fix VF root node parent queue priority"

* tag 'net-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (38 commits)
  ethtool: cmis_cdb: Fix incorrect read / write length extension
  selftests: netfilter: add test case for recent mismatch bug
  nft_set_pipapo: fix incorrect avx2 match of 5th field octet
  net: ppp: Add bound checking for skb data on ppp_sync_txmung
  net: Fix null-ptr-deref by sock_lock_init_class_and_name() and rmmod.
  ipv6: Align behavior across nexthops during path selection
  net: phy: allow MDIO bus PM ops to start/stop state machine for phylink-controlled PHY
  net: phy: move phy_link_change() prior to mdio_bus_phy_may_suspend()
  selftests/tc-testing: sfq: check that a derived limit of 1 is rejected
  net_sched: sch_sfq: move the limit validation
  net_sched: sch_sfq: use a temporary work area for validating configuration
  net: libwx: handle page_pool_dev_alloc_pages error
  selftests: mptcp: validate MPJoin HMacFailure counters
  mptcp: only inc MPJoinAckHMacFailure for HMAC failures
  rtnetlink: Fix bad unlock balance in do_setlink().
  net: ethtool: Don't call .cleanup_data when prepare_data fails
  tc: Ensure we have enough buffer space when sending filter netlink notifications
  net: libwx: Fix the wrong Rx descriptor field
  octeontx2-pf: qos: fix VF root node parent queue index
  selftests: tls: check that disconnect does nothing
  ...
2025-04-10 08:52:18 -07:00
Octavian Purdila b3bf8f63e6 net_sched: sch_sfq: move the limit validation
It is not sufficient to directly validate the limit on the data that
the user passes as it can be updated based on how the other parameters
are changed.

Move the check at the end of the configuration update process to also
catch scenarios where the limit is indirectly updated, for example
with the following configurations:

tc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 depth 1
tc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 divisor 1

This fixes the following syzkaller reported crash:

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:203:6
index 65535 is out of range for type 'struct sfq_head[128]'
CPU: 1 UID: 0 PID: 3037 Comm: syz.2.16 Not tainted 6.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x201/0x300 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0xf5/0x120 lib/ubsan.c:429
 sfq_link net/sched/sch_sfq.c:203 [inline]
 sfq_dec+0x53c/0x610 net/sched/sch_sfq.c:231
 sfq_dequeue+0x34e/0x8c0 net/sched/sch_sfq.c:493
 sfq_reset+0x17/0x60 net/sched/sch_sfq.c:518
 qdisc_reset+0x12e/0x600 net/sched/sch_generic.c:1035
 tbf_reset+0x41/0x110 net/sched/sch_tbf.c:339
 qdisc_reset+0x12e/0x600 net/sched/sch_generic.c:1035
 dev_reset_queue+0x100/0x1b0 net/sched/sch_generic.c:1311
 netdev_for_each_tx_queue include/linux/netdevice.h:2590 [inline]
 dev_deactivate_many+0x7e5/0xe70 net/sched/sch_generic.c:1375

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 10685681ba ("net_sched: sch_sfq: don't allow 1 packet limit")
Signed-off-by: Octavian Purdila <tavip@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-04-09 12:55:48 +01:00
Octavian Purdila 8c0cea59d4 net_sched: sch_sfq: use a temporary work area for validating configuration
Many configuration parameters have influence on others (e.g. divisor
-> flows -> limit, depth -> limit) and so it is difficult to correctly
do all of the validation before applying the configuration. And if a
validation error is detected late it is difficult to roll back a
partially applied configuration.

To avoid these issues use a temporary work area to update and validate
the configuration and only then apply the configuration to the
internal state.

Signed-off-by: Octavian Purdila <tavip@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-04-09 12:55:48 +01:00
Linus Torvalds 97c484ccb8 CRC cleanups for 6.15
Finish cleaning up the CRC kconfig options by removing the remaining
 unnecessary prompts and an unnecessary 'default y', removing
 CONFIG_LIBCRC32C, and documenting all the CRC library options.
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Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull CRC cleanups from Eric Biggers:
 "Finish cleaning up the CRC kconfig options by removing the remaining
  unnecessary prompts and an unnecessary 'default y', removing
  CONFIG_LIBCRC32C, and documenting all the CRC library options"

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
  lib/crc: remove CONFIG_LIBCRC32C
  lib/crc: document all the CRC library kconfig options
  lib/crc: remove unnecessary prompt for CONFIG_CRC_ITU_T
  lib/crc: remove unnecessary prompt for CONFIG_CRC_T10DIF
  lib/crc: remove unnecessary prompt for CONFIG_CRC16
  lib/crc: remove unnecessary prompt for CONFIG_CRC_CCITT
  lib/crc: remove unnecessary prompt for CONFIG_CRC32 and drop 'default y'
2025-04-08 12:09:28 -07:00
Toke Høiland-Jørgensen 369609fc62 tc: Ensure we have enough buffer space when sending filter netlink notifications
The tfilter_notify() and tfilter_del_notify() functions assume that
NLMSG_GOODSIZE is always enough to dump the filter chain. This is not
always the case, which can lead to silent notify failures (because the
return code of tfilter_notify() is not always checked). In particular,
this can lead to NLM_F_ECHO not being honoured even though an action
succeeds, which forces userspace to create workarounds[0].

Fix this by increasing the message size if dumping the filter chain into
the allocated skb fails. Use the size of the incoming skb as a size hint
if set, so we can start at a larger value when appropriate.

To trigger this, run the following commands:

 # ip link add type veth
 # tc qdisc replace dev veth0 root handle 1: fq_codel
 # tc -echo filter add dev veth0 parent 1: u32 match u32 0 0 $(for i in $(seq 32); do echo action pedit munge ip dport set 22; done)

Before this fix, tc just returns:

Not a filter(cmd 2)

After the fix, we get the correct echo:

added filter dev veth0 parent 1: protocol all pref 49152 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 terminal flowid not_in_hw
  match 00000000/00000000 at 0
	action order 1:  pedit action pass keys 1
 	index 1 ref 1 bind 1
	key #0  at 20: val 00000016 mask ffff0000
[repeated 32 times]

[0] 106ef21860

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Frode Nordahl <frode.nordahl@canonical.com>
Closes: https://bugs.launchpad.net/ubuntu/+source/openvswitch/+bug/2018500
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20250407105542.16601-1-toke@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-08 13:57:49 +02:00
Cong Wang 342debc121 codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()
After making all ->qlen_notify() callbacks idempotent, now it is safe to
remove the check of qlen!=0 from both fq_codel_dequeue() and
codel_qdisc_dequeue().

Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Fixes: 4b549a2ef4 ("fq_codel: Fair Queue Codel AQM")
Fixes: 76e3cc126b ("codel: Controlled Delay AQM")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211636.166257-1-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-08 10:57:56 +02:00