* [PATCH net-next v2 2/5] veth: implement Byte Queue Limits (BQL) for latency reduction
From: hawk @ 2026-04-13 9:44 UTC (permalink / raw)
To: netdev
Cc: kernel-team, Jesper Dangaard Brouer, Andrew Lunn, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Alexei Starovoitov,
Daniel Borkmann, John Fastabend, Stanislav Fomichev, linux-kernel,
bpf
In-Reply-To: <20260413094442.1376022-1-hawk@kernel.org>
From: Jesper Dangaard Brouer <hawk@kernel.org>
Commit dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to
reduce TX drops") gave qdiscs control over veth by returning
NETDEV_TX_BUSY when the ptr_ring is full (DRV_XOFF). That commit noted
a known limitation: the 256-entry ptr_ring sits in front of the qdisc as
a dark buffer, adding base latency because the qdisc has no visibility
into how many bytes are already queued there.
Add BQL support so the qdisc gets feedback and can begin shaping traffic
before the ring fills. In testing with fq_codel, BQL reduces ping RTT
under UDP load from ~6.61ms to ~0.36ms (18x).
Charge a fixed VETH_BQL_UNIT (1) per packet rather than skb->len, so
the DQL limit tracks packets-in-flight. Unlike a physical NIC, veth
has no link speed -- the ptr_ring drains at CPU speed and is
packet-indexed, not byte-indexed, so bytes are not the natural unit.
With byte-based charging, small packets sneak many more entries into
the ring before STACK_XOFF fires, deepening the dark buffer under
mixed-size workloads. Testing with a concurrent min-size packet flood
shows 3.7x ping RTT degradation with skb->len charging versus no
change with fixed-unit charging.
Charge BQL inside veth_xdp_rx() under the ptr_ring producer_lock, after
confirming the ring is not full. The charge must precede the produce
because the NAPI consumer can run on another CPU and complete the SKB
the instant it becomes visible in the ring. Doing both under the same
lock avoids a pre-charge/undo pattern -- BQL is only charged when
produce is guaranteed to succeed.
BQL is enabled only when a real qdisc is attached (guarded by
!qdisc_txq_has_no_queue), as HARD_TX_LOCK provides serialization
for TXQ modification like dql_queued(). For lltx devices, like veth,
this HARD_TX_LOCK serialization isn't provided. The ptr_ring
producer_lock provides additional serialization that would allow
BQL to work correctly even with noqueue, though that combination
is not currently enabled, as the netstack will drop and warn.
Track per-SKB BQL state via a VETH_BQL_FLAG pointer tag in the ptr_ring
entry. This is necessary because the qdisc can be replaced live while
SKBs are in-flight -- each SKB must carry the charge decision made at
enqueue time rather than re-checking the peer's qdisc at completion.
Complete per-SKB in veth_xdp_rcv() rather than in bulk, so STACK_XOFF
clears promptly when producer and consumer run on different CPUs.
BQL introduces a second independent queue-stop mechanism (STACK_XOFF)
alongside the existing DRV_XOFF (ring full). Both must be clear for
the queue to transmit. Reset BQL state in veth_napi_del_range() after
synchronize_net() to avoid racing with in-flight veth_poll() calls.
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
---
drivers/net/veth.c | 74 +++++++++++++++++++++++++++++++++++++++-------
1 file changed, 63 insertions(+), 11 deletions(-)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index e35df717e65e..6431dc40f9b4 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -34,9 +34,13 @@
#define DRV_VERSION "1.0"
#define VETH_XDP_FLAG BIT(0)
+#define VETH_BQL_FLAG BIT(1)
#define VETH_RING_SIZE 256
#define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
+/* Fixed BQL charge: DQL limit tracks packets-in-flight, not bytes */
+#define VETH_BQL_UNIT 1
+
#define VETH_XDP_TX_BULK_SIZE 16
#define VETH_XDP_BATCH 16
@@ -280,6 +284,21 @@ static bool veth_is_xdp_frame(void *ptr)
return (unsigned long)ptr & VETH_XDP_FLAG;
}
+static bool veth_ptr_is_bql(void *ptr)
+{
+ return (unsigned long)ptr & VETH_BQL_FLAG;
+}
+
+static struct sk_buff *veth_ptr_to_skb(void *ptr)
+{
+ return (void *)((unsigned long)ptr & ~VETH_BQL_FLAG);
+}
+
+static void *veth_skb_to_ptr(struct sk_buff *skb, bool bql)
+{
+ return bql ? (void *)((unsigned long)skb | VETH_BQL_FLAG) : skb;
+}
+
static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
{
return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
@@ -295,7 +314,7 @@ static void veth_ptr_free(void *ptr)
if (veth_is_xdp_frame(ptr))
xdp_return_frame(veth_ptr_to_xdp(ptr));
else
- kfree_skb(ptr);
+ kfree_skb(veth_ptr_to_skb(ptr));
}
static void __veth_xdp_flush(struct veth_rq *rq)
@@ -309,19 +328,33 @@ static void __veth_xdp_flush(struct veth_rq *rq)
}
}
-static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
+static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb, bool do_bql,
+ struct netdev_queue *txq)
{
- if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb)))
+ struct ptr_ring *ring = &rq->xdp_ring;
+
+ spin_lock(&ring->producer_lock);
+ if (unlikely(!ring->size) || __ptr_ring_full(ring)) {
+ spin_unlock(&ring->producer_lock);
return NETDEV_TX_BUSY; /* signal qdisc layer */
+ }
+
+ /* BQL charge before produce; consumer cannot see entry yet */
+ if (do_bql)
+ netdev_tx_sent_queue(txq, VETH_BQL_UNIT);
+
+ __ptr_ring_produce(ring, veth_skb_to_ptr(skb, do_bql));
+ spin_unlock(&ring->producer_lock);
return NET_RX_SUCCESS; /* same as NETDEV_TX_OK */
}
static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
- struct veth_rq *rq, bool xdp)
+ struct veth_rq *rq, bool xdp, bool do_bql,
+ struct netdev_queue *txq)
{
return __dev_forward_skb(dev, skb) ?: xdp ?
- veth_xdp_rx(rq, skb) :
+ veth_xdp_rx(rq, skb, do_bql, txq) :
__netif_rx(skb);
}
@@ -352,6 +385,7 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
struct net_device *rcv;
int length = skb->len;
bool use_napi = false;
+ bool do_bql = false;
int ret, rxq;
rcu_read_lock();
@@ -375,8 +409,11 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
}
skb_tx_timestamp(skb);
+ txq = netdev_get_tx_queue(dev, rxq);
- ret = veth_forward_skb(rcv, skb, rq, use_napi);
+ /* BQL charge happens inside veth_xdp_rx() under producer_lock */
+ do_bql = use_napi && !qdisc_txq_has_no_queue(txq);
+ ret = veth_forward_skb(rcv, skb, rq, use_napi, do_bql, txq);
switch (ret) {
case NET_RX_SUCCESS: /* same as NETDEV_TX_OK */
if (!use_napi)
@@ -388,8 +425,6 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
/* If a qdisc is attached to our virtual device, returning
* NETDEV_TX_BUSY is allowed.
*/
- txq = netdev_get_tx_queue(dev, rxq);
-
if (qdisc_txq_has_no_queue(txq)) {
dev_kfree_skb_any(skb);
goto drop;
@@ -412,6 +447,7 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
net_crit_ratelimited("%s(%s): Invalid return code(%d)",
__func__, dev->name, ret);
}
+
rcu_read_unlock();
return ret;
@@ -900,7 +936,8 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
static int veth_xdp_rcv(struct veth_rq *rq, int budget,
struct veth_xdp_tx_bq *bq,
- struct veth_stats *stats)
+ struct veth_stats *stats,
+ struct netdev_queue *peer_txq)
{
int i, done = 0, n_xdpf = 0;
void *xdpf[VETH_XDP_BATCH];
@@ -928,9 +965,13 @@ static int veth_xdp_rcv(struct veth_rq *rq, int budget,
}
} else {
/* ndo_start_xmit */
- struct sk_buff *skb = ptr;
+ bool bql_charged = veth_ptr_is_bql(ptr);
+ struct sk_buff *skb = veth_ptr_to_skb(ptr);
stats->xdp_bytes += skb->len;
+ if (peer_txq && bql_charged)
+ netdev_tx_completed_queue(peer_txq, 1, VETH_BQL_UNIT);
+
skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
if (skb) {
if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
@@ -975,7 +1016,7 @@ static int veth_poll(struct napi_struct *napi, int budget)
peer_txq = peer_dev ? netdev_get_tx_queue(peer_dev, queue_idx) : NULL;
xdp_set_return_frame_no_direct();
- done = veth_xdp_rcv(rq, budget, &bq, &stats);
+ done = veth_xdp_rcv(rq, budget, &bq, &stats, peer_txq);
if (stats.xdp_redirect > 0)
xdp_do_flush();
@@ -1073,6 +1114,7 @@ static int __veth_napi_enable(struct net_device *dev)
static void veth_napi_del_range(struct net_device *dev, int start, int end)
{
struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
int i;
for (i = start; i < end; i++) {
@@ -1091,6 +1133,15 @@ static void veth_napi_del_range(struct net_device *dev, int start, int end)
ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
}
+ /* Reset BQL on peer's txqs: remaining ring items were freed above
+ * without BQL completion, so DQL state must be reset.
+ */
+ peer = rtnl_dereference(priv->peer);
+ if (peer) {
+ for (i = start; i < end; i++)
+ netdev_tx_reset_queue(netdev_get_tx_queue(peer, i));
+ }
+
for (i = start; i < end; i++) {
page_pool_destroy(priv->rq[i].page_pool);
priv->rq[i].page_pool = NULL;
@@ -1740,6 +1791,7 @@ static void veth_setup(struct net_device *dev)
dev->priv_flags |= IFF_PHONY_HEADROOM;
dev->priv_flags |= IFF_DISABLE_NETPOLL;
dev->lltx = true;
+ dev->bql = true;
dev->netdev_ops = &veth_netdev_ops;
dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
--
2.43.0
^ permalink raw reply related
* [PATCH net-next v2 1/5] net: add dev->bql flag to allow BQL sysfs for IFF_NO_QUEUE devices
From: hawk @ 2026-04-13 9:44 UTC (permalink / raw)
To: netdev
Cc: kernel-team, Jesper Dangaard Brouer, Jonas Köppeler,
Andrew Lunn, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Jonathan Corbet, Shuah Khan,
Kuniyuki Iwashima, Stanislav Fomichev, Frederic Weisbecker,
Yajun Deng, Krishna Kumar, linux-doc, linux-kernel
In-Reply-To: <20260413094442.1376022-1-hawk@kernel.org>
From: Jesper Dangaard Brouer <hawk@kernel.org>
Virtual devices with IFF_NO_QUEUE or lltx are excluded from BQL sysfs
by netdev_uses_bql(), since they traditionally lack real hardware
queues. However, some virtual devices like veth implement a real
ptr_ring FIFO with NAPI processing and benefit from BQL to limit
in-flight bytes and reduce latency.
Add a per-device 'bql' bitfield boolean in the priv_flags_slow section
of struct net_device. When set, it overrides the IFF_NO_QUEUE/lltx
exclusion and exposes BQL sysfs entries (/sys/class/net/<dev>/queues/
tx-<n>/byte_queue_limits/). The flag is still gated on CONFIG_BQL.
This allows drivers that use BQL despite being IFF_NO_QUEUE to opt in
to sysfs visibility for monitoring and debugging.
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Tested-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
---
Documentation/networking/net_cachelines/net_device.rst | 1 +
include/linux/netdevice.h | 2 ++
net/core/net-sysfs.c | 8 +++++++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst
index 1c19bb7705df..b775d3235a2d 100644
--- a/Documentation/networking/net_cachelines/net_device.rst
+++ b/Documentation/networking/net_cachelines/net_device.rst
@@ -170,6 +170,7 @@ unsigned_long:1 see_all_hwtstamp_requests
unsigned_long:1 change_proto_down
unsigned_long:1 netns_immutable
unsigned_long:1 fcoe_mtu
+unsigned_long:1 bql netdev_uses_bql(net-sysfs.c)
struct list_head net_notifier_list
struct macsec_ops* macsec_ops
struct udp_tunnel_nic_info* udp_tunnel_nic_info
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 47417b2d48a4..7a1a491ecdd5 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2048,6 +2048,7 @@ enum netdev_reg_state {
* @change_proto_down: device supports setting carrier via IFLA_PROTO_DOWN
* @netns_immutable: interface can't change network namespaces
* @fcoe_mtu: device supports maximum FCoE MTU, 2158 bytes
+ * @bql: device uses BQL (DQL sysfs) despite having IFF_NO_QUEUE
*
* @net_notifier_list: List of per-net netdev notifier block
* that follow this device when it is moved
@@ -2462,6 +2463,7 @@ struct net_device {
unsigned long change_proto_down:1;
unsigned long netns_immutable:1;
unsigned long fcoe_mtu:1;
+ unsigned long bql:1;
struct list_head net_notifier_list;
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index e430645748a7..4360efc8f241 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1945,10 +1945,16 @@ static const struct kobj_type netdev_queue_ktype = {
static bool netdev_uses_bql(const struct net_device *dev)
{
+ if (!IS_ENABLED(CONFIG_BQL))
+ return false;
+
+ if (dev->bql)
+ return true;
+
if (dev->lltx || (dev->priv_flags & IFF_NO_QUEUE))
return false;
- return IS_ENABLED(CONFIG_BQL);
+ return true;
}
static int netdev_queue_add_kobject(struct net_device *dev, int index)
--
2.43.0
^ permalink raw reply related
* [PATCH net-next v2 0/5] veth: add Byte Queue Limits (BQL) support
From: hawk @ 2026-04-13 9:44 UTC (permalink / raw)
To: netdev
Cc: kernel-team, Jesper Dangaard Brouer, Chris Arges, Mike Freemon,
Toke Høiland-Jørgensen, Shuah Khan, linux-kselftest,
Jonas Köppeler, Alexei Starovoitov, Daniel Borkmann,
David S. Miller, Jakub Kicinski, John Fastabend,
Stanislav Fomichev, bpf
From: Jesper Dangaard Brouer <hawk@kernel.org>
This series adds BQL (Byte Queue Limits) to the veth driver, reducing
latency by dynamically limiting in-flight packets in the ptr_ring and
moving buffering into the qdisc where AQM algorithms can act on it.
Problem:
veth's 256-entry ptr_ring acts as a "dark buffer" -- packets queued
there are invisible to the qdisc's AQM. Under load, the ring fills
completely (DRV_XOFF backpressure), adding up to 256 packets of
unmanaged latency before the qdisc even sees congestion.
Solution:
BQL (STACK_XOFF) dynamically limits in-flight packets, stopping the
queue before the ring fills. This keeps the ring shallow and pushes
excess packets into the qdisc, where sojourn-based AQM can measure
and drop them.
Test setup: veth pair, UDP flood, 13000 iptables rules in consumer
namespace (slows NAPI-64 cycle to ~6-7ms), ping measures RTT under load.
BQL off BQL on
fq_codel: RTT ~22ms, 4% loss RTT ~1.3ms, 0% loss
sfq: RTT ~24ms, 0% loss RTT ~1.5ms, 0% loss
BQL reduces ping RTT by ~17x for both qdiscs. Consumer throughput
is unchanged (~10K pps) -- BQL adds no overhead.
CoDel bug discovered during BQL development:
Our original motivation for BQL was fq_codel ping loss observed under
load (4-26% depending on NAPI cycle time). Investigating this led us
to discover a bug in the CoDel implementation: codel_dequeue() does
not reset vars->first_above_time when a flow goes empty, contrary to
the reference algorithm. This causes stale CoDel state to persist
across empty periods in fq_codel's per-flow queues, penalizing sparse
flows like ICMP ping. A fix for this has been applied to the net tree:
https://git.kernel.org/netdev/net/c/815980fe6dbb
BQL remains valuable independently: it reduces RTT by ~17x by moving
buffering from the dark ptr_ring into the qdisc. Additionally, BQL
clears STACK_XOFF per-SKB as each packet completes, rather than
batch-waking after 64 packets (DRV_XOFF). This keeps sojourn times
below fq_codel's target, preventing CoDel from entering dropping
state on non-congested flows in the first place.
Key design decisions:
- Charge-under-lock in veth_xdp_rx(): The BQL charge must precede
the ptr_ring produce, because the NAPI consumer can run on another
CPU and complete the SKB immediately after it becomes visible. To
avoid a pre-charge/undo pattern, the charge is done under the
ptr_ring producer_lock after confirming the ring is not full. BQL
is only charged when produce is guaranteed to succeed, keeping
num_queued monotonically increasing. HARD_TX_LOCK already
serializes dql_queued() (veth requires a qdisc for BQL); the
ptr_ring lock additionally would allow noqueue to work correctly.
- Per-SKB BQL tracking via pointer tag: A VETH_BQL_FLAG bit in the
ptr_ring pointer records whether each SKB was BQL-charged. This is
necessary because the qdisc can be replaced live (noqueue->sfq or
vice versa) while SKBs are in-flight -- the completion side must
know the charge state that was decided at enqueue time.
- IFF_NO_QUEUE + BQL coexistence: A new dev->bql flag enables BQL
sysfs exposure for IFF_NO_QUEUE devices that opt in to DQL
accounting, without changing IFF_NO_QUEUE semantics.
Background and acknowledgments:
Mike Freemon reported the veth dark buffer problem internally at
Cloudflare and showed that recompiling the kernel with a ptr_ring
size of 30 (down from 256) made fq_codel work dramatically better.
This was the primary motivation for a proper BQL solution that
achieves the same effect dynamically without a kernel rebuild.
Chris Arges wrote a reproducer for the dark buffer latency problem:
https://github.com/netoptimizer/veth-backpressure-performance-testing
This is where we first observed ping packets being dropped under
fq_codel, which became our secondary motivation for BQL. In
production we switched to SFQ on veth devices as a workaround.
Jonas Koeppeler provided extensive testing and code review.
Together we discovered that the fq_codel ping loss was actually a
12-year-old CoDel bug (stale first_above_time in empty flows), not
caused by the dark buffer itself. A fix has been applied to the net tree:
https://git.kernel.org/netdev/net/c/815980fe6dbb
Patch overview:
1. net: add dev->bql flag to allow BQL sysfs for IFF_NO_QUEUE devices
2. veth: implement Byte Queue Limits (BQL) for latency reduction
3. veth: add tx_timeout watchdog as BQL safety net
4. net: sched: add timeout count to NETDEV WATCHDOG message
5. selftests: net: add veth BQL stress test
Jesper Dangaard Brouer (5):
net: add dev->bql flag to allow BQL sysfs for IFF_NO_QUEUE devices
veth: implement Byte Queue Limits (BQL) for latency reduction
veth: add tx_timeout watchdog as BQL safety net
net: sched: add timeout count to NETDEV WATCHDOG message
selftests: net: add veth BQL stress test
.../networking/net_cachelines/net_device.rst | 1 +
drivers/net/veth.c | 92 +-
include/linux/netdevice.h | 2 +
net/core/net-sysfs.c | 8 +-
net/sched/sch_generic.c | 8 +-
tools/testing/selftests/net/Makefile | 3 +
tools/testing/selftests/net/config | 1 +
tools/testing/selftests/net/napi_poll_hist.bt | 40 +
tools/testing/selftests/net/veth_bql_test.sh | 821 ++++++++++++++++++
.../selftests/net/veth_bql_test_virtme.sh | 124 +++
10 files changed, 1084 insertions(+), 16 deletions(-)
create mode 100644 tools/testing/selftests/net/napi_poll_hist.bt
create mode 100755 tools/testing/selftests/net/veth_bql_test.sh
create mode 100755 tools/testing/selftests/net/veth_bql_test_virtme.sh
V1: https://lore.kernel.org/all/20260324174719.1224337-1-hawk@kernel.org/
Changes since V1:
- Patch 1 (dev->bql flag): add kdoc entry for @bql in struct net_device.
- Patch 2 (veth BQL): charge fixed VETH_BQL_UNIT (1) per packet instead
of skb->len. veth has no link speed; the ptr_ring is packet-indexed.
Byte-based charging lets small packets sneak many entries into the ring.
Testing: min-size packet flood causes 3.7x ping RTT degradation with
skb->len vs no change with fixed-unit charging.
- Patch 3 (tx_timeout watchdog): fix race with peer NAPI: replace
netdev_tx_reset_queue() with clear_bit(STACK_XOFF) + netif_tx_wake_queue()
to avoid dql_reset() racing with concurrent dql_completed().
- Patch 5 (selftests): fix shellcheck warnings and infos:
- Quote variables passed to kill_process and exit.
- Declare and assign local variables separately (SC2155).
- Use read -r to avoid mangling backslashes (SC2162).
- Add shellcheck disable comments for intentional word splitting
(set -- $line, tc $qdisc $opts) and indirect invocation (trap).
- Make iptables-restore failure a hard FAIL instead of continuing.
- Add veth_bql_test.sh to TEST_PROGS in net/Makefile.
- Add veth_bql_test_virtme.sh to TEST_FILES (needs kernel build tree).
- Add napi_poll_hist.bt to TEST_FILES in net/Makefile.
- Add CONFIG_NET_SCH_SFQ=m to net/config (default qdisc is sfq).
- Reduce default test duration from 300s to 30s for kselftest CI.
- Fix virtme wrapper: empty args bug, check vmlinux instead of test path.
- Cover letter: update CoDel fix reference to merged commit in net tree.
Cc: Chris Arges <carges@cloudflare.com>
Cc: Mike Freemon <mfreemon@cloudflare.com>
Cc: Toke Høiland-Jørgensen <toke@toke.dk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Cc: kernel-team@cloudflare.com
--
2.43.0
^ permalink raw reply
* [PATCH] net: sched: teql: fix use-after-free in teql_master_xmit
From: Kito Xu (veritas501) @ 2026-04-13 9:44 UTC (permalink / raw)
To: Jamal Hadi Salim, Jiri Pirko, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni
Cc: Simon Horman, netdev, linux-kernel, Kito Xu (veritas501)
teql_destroy() traverses the circular slave list to unlink a slave
qdisc. It reads master->slaves as both the starting point and the
do-while termination sentinel. However, the data-path writers
teql_dequeue() and teql_master_xmit() concurrently modify
master->slaves without holding RTNL, running in softirq or process
context respectively. If master->slaves is overwritten to an
already-visited node mid-traversal, the loop exits early without
finding the target slave. The slave is never unlinked, but its memory
is freed by call_rcu() -- leaving a dangling pointer in the circular
list. The next teql_master_xmit() traversal dereferences freed memory.
race condition:
CPU 0 (teql_destroy, RTNL held) CPU 1 (teql_dequeue, softirq)
----------------------------------- -----------------------------
prev = master->slaves; // = A
q = NEXT_SLAVE(A); // = B
B == A? No.
prev = B;
/* slave C's queue drains */
skb == NULL ->
dat->m->slaves = C; /* write! */
q = NEXT_SLAVE(B); // = C
C == A? No.
prev = C;
/* check: (prev=C) != master->slaves(C)?
FALSE -> loop exits! */
/* A never unlinked, freed by call_rcu */
CPU 0 (teql_master_xmit, later)
-----------------------------------
q = NEXT_SLAVE(C); // = A (freed!)
slave = qdisc_dev(A); // UAF!
Fix this by saving master->slaves into a local `head` variable at the
start of teql_destroy() and using it as a stable sentinel for the
entire traversal. Also annotate all data-path accesses to
master->slaves with READ_ONCE/WRITE_ONCE to prevent store-tearing and
compiler-introduced re-reads.
==================================================================
BUG: KASAN: slab-use-after-free in teql_master_xmit+0xeae/0x14a0
Read of size 8 at addr ffff888018074040 by task poc/162
CPU: 2 UID: 0 PID: 162 Comm: poc Not tainted 7.0.0-rc7-next-20260410 #10 PREEMPTLAZY
Call Trace:
<TASK>
dump_stack_lvl+0x64/0x80
print_report+0xd0/0x5e0
kasan_report+0xce/0x100
teql_master_xmit+0xeae/0x14a0
dev_hard_start_xmit+0xcd/0x5b0
sch_direct_xmit+0x12e/0xac0
__qdisc_run+0x3b1/0x1a70
__dev_queue_xmit+0x2257/0x3100
ip_finish_output2+0x615/0x19c0
ip_output+0x158/0x2b0
ip_send_skb+0x11b/0x160
udp_send_skb+0x64b/0xd80
udp_sendmsg+0x138c/0x1ec0
__sys_sendto+0x331/0x3a0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x64/0x680
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The buggy address belongs to the object at ffff888018074000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 64 bytes inside of
freed 512-byte region [ffff888018074000, ffff888018074200)
==================================================================
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kito Xu (veritas501) <hxzene@gmail.com>
---
net/sched/sch_teql.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index ec4039a201a2..2e86397a5219 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -101,7 +101,7 @@ teql_dequeue(struct Qdisc *sch)
if (skb == NULL) {
struct net_device *m = qdisc_dev(q);
if (m) {
- dat->m->slaves = sch;
+ WRITE_ONCE(dat->m->slaves, sch);
netif_wake_queue(m);
}
} else {
@@ -136,19 +136,23 @@ teql_destroy(struct Qdisc *sch)
if (!master)
return;
- prev = master->slaves;
+ prev = READ_ONCE(master->slaves);
if (prev) {
+ struct Qdisc *head = prev;
+
do {
q = NEXT_SLAVE(prev);
if (q == sch) {
NEXT_SLAVE(prev) = NEXT_SLAVE(q);
- if (q == master->slaves) {
- master->slaves = NEXT_SLAVE(q);
- if (q == master->slaves) {
+ if (q == head) {
+ WRITE_ONCE(master->slaves,
+ NEXT_SLAVE(q));
+ if (q == NEXT_SLAVE(q)) {
struct netdev_queue *txq;
txq = netdev_get_tx_queue(master->dev, 0);
- master->slaves = NULL;
+ WRITE_ONCE(master->slaves,
+ NULL);
dev_reset_queue(master->dev,
txq, NULL);
@@ -158,7 +162,7 @@ teql_destroy(struct Qdisc *sch)
break;
}
- } while ((prev = q) != master->slaves);
+ } while ((prev = q) != head);
}
}
@@ -285,7 +289,7 @@ static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
int subq = skb_get_queue_mapping(skb);
struct sk_buff *skb_res = NULL;
- start = master->slaves;
+ start = READ_ONCE(master->slaves);
restart:
nores = 0;
@@ -317,7 +321,7 @@ static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
netdev_start_xmit(skb, slave, slave_txq, false) ==
NETDEV_TX_OK) {
__netif_tx_unlock(slave_txq);
- master->slaves = NEXT_SLAVE(q);
+ WRITE_ONCE(master->slaves, NEXT_SLAVE(q));
netif_wake_queue(dev);
master->tx_packets++;
master->tx_bytes += length;
@@ -329,7 +333,7 @@ static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
busy = 1;
break;
case 1:
- master->slaves = NEXT_SLAVE(q);
+ WRITE_ONCE(master->slaves, NEXT_SLAVE(q));
return NETDEV_TX_OK;
default:
nores = 1;
--
2.43.0
^ permalink raw reply related
* Re: [PATCH v5] net: caif: fix stack out-of-bounds write in cfctrl_link_setup()
From: Paolo Abeni @ 2026-04-13 9:30 UTC (permalink / raw)
To: Simon Horman, Kangzheng Gu
Cc: davem, edumazet, kuba, kees, thorsten.blum, arnd, sjur.brandeland,
netdev, linux-kernel, stable
In-Reply-To: <20260412135743.GK469338@kernel.org>
On 4/12/26 3:57 PM, Simon Horman wrote:
> I am wondering if it would be best to follow the pattern for
> writing linkparam.u.utility.name elsewhere in this function.
> That:
> 1. Uses a somewhat more succinct loop control structure
> 2. Silently truncates input without updating cmdrsp if overrun would occur
>
> Something like this (compile tested only!):
>
> diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c
> index c6cc2bfed65d..ba184c11386e 100644
> --- a/net/caif/cfctrl.c
> +++ b/net/caif/cfctrl.c
> @@ -15,6 +15,7 @@
> #include <net/caif/cfctrl.h>
>
> #define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
> +#define RFM_VOLUME_LEN 20
> #define UTILITY_NAME_LENGTH 16
> #define CFPKT_CTRL_PKT_LEN 20
>
> @@ -414,10 +415,11 @@ static int cfctrl_link_setup(struct cfctrl *cfctrl, struct cfpkt *pkt, u8 cmdrsp
> */
> linkparam.u.rfm.connid = cfpkt_extr_head_u32(pkt);
> cp = (u8 *) linkparam.u.rfm.volume;
> - for (tmp = cfpkt_extr_head_u8(pkt);
> - cfpkt_more(pkt) && tmp != '\0';
> - tmp = cfpkt_extr_head_u8(pkt))
> + caif_assert(sizeof(linkparam.u.rfm.volume) >= RFM_VOLUME_LEN);
> + for(i = 0; i < RFM_VOLUME_LEN - 1 && cfpkt_more(pkt); i++) {
> + tmp = cfpkt_extr_head_u8(pkt);
> *cp++ = tmp;
> + }
> *cp = '\0';
>
> if (CFCTRL_ERR_BIT & cmdrsp)
I agree that the code suggested by Simon is clearer. Note that AFAICS it
lacks an additional `tmp!= '\0'` check to break the loop, but even with
that added it should be preferable.
Thanks,
Paolo
^ permalink raw reply
* Re: [PATCH net-next v2 3/3] net: mdio: treat PSE EPROBE_DEFER as non-fatal during PHY registration
From: Kory Maincent @ 2026-04-13 9:28 UTC (permalink / raw)
To: Andrew Lunn
Cc: Russell King (Oracle), Carlo Szelinsky, o.rempel, andrew+netdev,
hkallweit1, kuba, davem, edumazet, pabeni, horms, netdev,
linux-kernel
In-Reply-To: <280018e9-4499-4a13-b692-6d6a4499477b@lunn.ch>
On Thu, 9 Apr 2026 21:54:33 +0200
Andrew Lunn <andrew@lunn.ch> wrote:
> On Thu, Apr 09, 2026 at 05:08:33PM +0100, Russell King (Oracle) wrote:
> > On Thu, Apr 09, 2026 at 05:34:56PM +0200, Andrew Lunn wrote:
> > > I still think we should be deferring probe until we have all the parts
> > > available. The question is, how do we actually do that?
> >
> > Indeed...
> >
> > > We could insist that MACs being used with PSE need to call
> > > phylink_connect() in probe, so we can return EPROBE_DEFER. We might
> > > actually need a new API method, phylink_connect_probe(). That can call
> > > down into phylib, maybe again new API methods, which will not bind
> > > genphy, but return EPROBE_DEFER.
>
> I did not say i would be easy...
>
> > How would MACs know whether they should call phylink_connect_probe()
> > or phylink_connect_phy() ?
>
> It would not. Anybody with a board using PSE would need to modify the
> MAC driver to use phylink_connect_probe(), if they have a slow to load
> PSE device.
>
> > What do we do about MAC drivers that are a single driver and device,
> > but are made up of several network devices (like Marvell PP2) ?
>
> It would need more care, but it should work. You might end up removing
> a perfectly good device because the other one is missing its PHY,
> which is not ideal, but hopefully you get there in the end.
>
> > We also have network drivers that provide a MDIO bus for a different
> > network device, which makes connecting the PHY harder in the probe
> > path.
>
> Yes, we would see such setup doing more deferred probing, but again,
> they should get there in the end. The most common systems doing this
> are using the FEC. Are there any board using the FEC and problematic
> PSE?
Not that I know of but it is only the beginning of PSE support in Linux.
> > Lastly, what do we do where a PHY driver hasn't been configured or
> > doesn't exist for the PHY?
>
> I was wondering if we can get from the driver core some idea where we
> are in the deferred probing window. If we are 2/3 of the way through
> the window, fall back to genphy?
How could we decide when to fall back to genphy and when to continue the
defer situation?
> I'm not saying we should change all MAC drivers, or recommend new MAC
> drivers connect to the PHY in probe. I just want to offer the option
> if you have a problematic PSE or PHY, change the MAC driver.
>
> What we have also said in the past, it is the bootloaders problem to
> download firmware into the PHY, or PSE, so that it is ready to go by
> the time Linux boots. That would also be the simpler solution here.
My thought of using MDI was to separate the hardware port from the PHY device,
as in hardware, the PSE is directly wired to the MDI we should have the binding
similar.
I was thinking of adding a new helper to register the MDIs for the MACs.
In the MAC/SWITCH binding we could have a list of MDIs similarly to that:
https://elixir.bootlin.com/linux/v7.0-rc7/source/Documentation/devicetree/bindings/net/ethernet-phy.yaml#L332
We could have the SFP and PSE phandle directly in that node.
For example prestera driver is already doing something similar for SFP:
https://elixir.bootlin.com/linux/v7.0-rc7/source/drivers/net/ethernet/marvell/prestera/prestera_main.c#L370
I wanted to convert this helper into a generic one. Then every MAC/Switch
driver could just simply call the new helper to register their MDIs. I am
surely missing lots of things as I am not as net expert as you, but what do you
think of that?
We would have one path into phylink and one trough the new helper when there is
no PHY devices registered.
Maxime what do you think as you are actively working on MDIs?
Still, this does not reply the initial question, should we keep EPROBE_DEFER
in phylink if the PSE is not found or should we have have a way to probe the
PHY and solve the PSE phandle later?
Regards,
--
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
^ permalink raw reply
* Re: [patch 07/38] treewide: Consolidate cycles_t
From: Ojaswin Mujoo @ 2026-04-13 9:15 UTC (permalink / raw)
To: Thomas Gleixner
Cc: LKML, Arnd Bergmann, x86, Lu Baolu, iommu, Michael Grzeschik,
netdev, linux-wireless, Herbert Xu, linux-crypto, Vlastimil Babka,
linux-mm, David Woodhouse, Bernie Thompson, linux-fbdev,
Theodore Tso, linux-ext4, Andrew Morton, Uladzislau Rezki,
Marco Elver, Dmitry Vyukov, kasan-dev, Andrey Ryabinin,
Thomas Sailer, linux-hams, Jason A. Donenfeld, Richard Henderson,
linux-alpha, Russell King, linux-arm-kernel, Catalin Marinas,
Huacai Chen, loongarch, Geert Uytterhoeven, linux-m68k,
Dinh Nguyen, Jonas Bonn, linux-openrisc, Helge Deller,
linux-parisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux
In-Reply-To: <20260410120318.045532623@kernel.org>
On Fri, Apr 10, 2026 at 02:19:03PM +0200, Thomas Gleixner wrote:
> Most architectures define cycles_t as unsigned long execpt:
>
> - x86 requires it to be 64-bit independent of the 32-bit/64-bit build.
>
> - parisc and mips define it as unsigned int
>
> parisc has no real reason to do so as there are only a few usage sites
> which either expand it to a 64-bit value or utilize only the lower
> 32bits.
>
> mips has no real requirement either.
>
> Move the typedef to types.h and provide a config switch to enforce the
> 64-bit type for x86.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> ---
> arch/Kconfig | 4 ++++
> arch/alpha/include/asm/timex.h | 3 ---
> arch/arm/include/asm/timex.h | 1 -
> arch/loongarch/include/asm/timex.h | 2 --
> arch/m68k/include/asm/timex.h | 2 --
> arch/mips/include/asm/timex.h | 2 --
> arch/nios2/include/asm/timex.h | 2 --
> arch/parisc/include/asm/timex.h | 2 --
> arch/powerpc/include/asm/timex.h | 4 +---
> arch/riscv/include/asm/timex.h | 2 --
> arch/s390/include/asm/timex.h | 2 --
> arch/sparc/include/asm/timex_64.h | 1 -
> arch/x86/Kconfig | 1 +
> arch/x86/include/asm/tsc.h | 2 --
> include/asm-generic/timex.h | 1 -
> include/linux/types.h | 6 ++++++
> 16 files changed, 12 insertions(+), 25 deletions(-)
>
<...>
> --- a/arch/powerpc/include/asm/timex.h
> +++ b/arch/powerpc/include/asm/timex.h
> @@ -11,9 +11,7 @@
> #include <asm/cputable.h>
> #include <asm/vdso/timebase.h>
>
> -typedef unsigned long cycles_t;
> -
> -static inline cycles_t get_cycles(void)
> +ostatic inline cycles_t get_cycles(void)
Hi Thomas, I'm in middle of testing this series on powerpc. In the meantime I
noticed that there's probably a small typo here (althrough this is fixed
later)
Regards,
ojaswin
> {
> return mftb();
> }
^ permalink raw reply
* Re: [PATCH net-next v5 1/2] net: hsr: require valid EOT supervision TLV
From: Felix Maurer @ 2026-04-13 9:14 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: Luka Gejak, davem, edumazet, pabeni, netdev, horms
In-Reply-To: <20260412133157.3b335e1b@kernel.org>
On Sun, Apr 12, 2026 at 01:31:57PM -0700, Jakub Kicinski wrote:
> On Sun, 12 Apr 2026 22:13:35 +0200 Luka Gejak wrote:
> > Regarding the TLV loop: I actually implemented a TLV walker in v4 [1]
> > for this exact reason, but I moved to strict sequential parsing in v5
> > based on reviewer's feedback to keep the implementation simple. Could
> > you please check if the approach used in v4 is what you had in mind?
> > If so, I will rebase that logic onto the memory safety fixes
> > (pskb_may_pull) from v5 and submit it as v6.
>
> That's not really what I had in mind. I was thinking of a loop which
> just skips the TLVs in order, leaving the parsing of known TLVs as is.
> But I've never used HSR maybe this sort of strict validation is somehow
> okay in HSR deployments.
Hi Jakub,
I'm chiming in here as I was one of the reviewers asking for the strict
validation. The HSR supervision frames have this TLV structure that may
appear to support optionals or (unknown) extensions of some kind. But
the standard just has two potential frame formats (for normal and RedBox
supervision frames), both of them completely specified. Also, the
supervision frames have a version field in the beginning. IMHO, this
leaves no room to put other TLVs there. Therefore, I don't think we gain
anything but unexpected behavior if we start accepting frames with
arbitrary additional TLVs/data.
Thanks,
Felix
^ permalink raw reply
* Re: [PATCH] rose: Fix rose_find_socket() returning without sock_hold()
From: Eric Dumazet @ 2026-04-13 9:10 UTC (permalink / raw)
To: Dudu Lu; +Cc: netdev, davem, kuba, pabeni
In-Reply-To: <20260413090420.79932-1-phx0fer@gmail.com>
On Mon, Apr 13, 2026 at 2:04 AM Dudu Lu <phx0fer@gmail.com> wrote:
>
> rose_find_socket() returns a raw socket pointer after releasing
> rose_list_lock. The socket can be freed by a concurrent close()
> between the unlock and the caller's use of the pointer, leading
> to a use-after-free.
>
> Add sock_hold() before returning the found socket, and update
> callers to sock_put() when done.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Dudu Lu <phx0fer@gmail.com>
> ---
> net/rose/af_rose.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
> index ba56213e0a2a..b32b136f80aa 100644
> --- a/net/rose/af_rose.c
> +++ b/net/rose/af_rose.c
> @@ -1,4 +1,5 @@
> -// SPDX-License-Identifier: GPL-2.0-or-later
> + if (s)
> + sock_hold(s);// SPDX-License-Identifier: GPL-2.0-or-later
> /*
> *
> * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
> --
> 2.39.3 (Apple Git-145)
>
I suggest that your patches are checked by one human, before sending
them to the lists.
^ permalink raw reply
* [PATCH net 1/1] net: bridge: use a stable FDB dst snapshot in RCU readers
From: Ren Wei @ 2026-04-13 9:08 UTC (permalink / raw)
To: bridge, netdev
Cc: razor, idosch, davem, edumazet, kuba, pabeni, horms,
makita.toshiaki, vyasevic, yifanwucs, tomapufckgml, yuantan098,
bird, enjou1224z, zcliangcn, n05ec
In-Reply-To: <cover.1776043229.git.zcliangcn@gmail.com>
From: Zhengchuan Liang <zcliangcn@gmail.com>
Local FDB entries can be rewritten in place by `fdb_delete_local()`, which
updates `f->dst` to another port or to `NULL` while keeping the entry
alive. Several bridge RCU readers inspect `f->dst`, including
`br_fdb_fillbuf()` through the `brforward_read()` sysfs path.
These readers currently load `f->dst` multiple times and can therefore
observe inconsistent values across the check and later dereference.
In `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change
`f->dst` after the NULL check and before the `port_no` dereference,
leading to a NULL-ptr-deref.
Fix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each
affected RCU reader and using that snapshot for the rest of the access
sequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()`
with `WRITE_ONCE()` so the readers and writer use matching access patterns.
Fixes: 960b589f86c7 ("bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address")
Cc: stable@kernel.org
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Tested-by: Ren Wei <enjou1224z@gmail.com>
Signed-off-by: Zhengchuan Liang <zcliangcn@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
---
net/bridge/br_arp_nd_proxy.c | 8 +++++---
net/bridge/br_fdb.c | 28 ++++++++++++++++++----------
2 files changed, 23 insertions(+), 13 deletions(-)
diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index 6b5595868a39c..7ace0f4941bb6 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -202,11 +202,12 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br,
f = br_fdb_find_rcu(br, n->ha, vid);
if (f) {
+ const struct net_bridge_port *dst = READ_ONCE(f->dst);
bool replied = false;
if ((p && (p->flags & BR_PROXYARP)) ||
- (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)) ||
- br_is_neigh_suppress_enabled(f->dst, vid)) {
+ (dst && (dst->flags & BR_PROXYARP_WIFI)) ||
+ br_is_neigh_suppress_enabled(dst, vid)) {
if (!vid)
br_arp_send(br, p, skb->dev, sip, tip,
sha, n->ha, sha, 0, 0);
@@ -470,9 +471,10 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br,
f = br_fdb_find_rcu(br, n->ha, vid);
if (f) {
+ const struct net_bridge_port *dst = READ_ONCE(f->dst);
bool replied = false;
- if (br_is_neigh_suppress_enabled(f->dst, vid)) {
+ if (br_is_neigh_suppress_enabled(dst, vid)) {
if (vid != 0)
br_nd_send(br, p, skb, n,
skb->vlan_proto,
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index e2c17f620f009..6eb3ab69a5140 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -236,6 +236,7 @@ struct net_device *br_fdb_find_port(const struct net_device *br_dev,
const unsigned char *addr,
__u16 vid)
{
+ const struct net_bridge_port *dst;
struct net_bridge_fdb_entry *f;
struct net_device *dev = NULL;
struct net_bridge *br;
@@ -248,8 +249,11 @@ struct net_device *br_fdb_find_port(const struct net_device *br_dev,
br = netdev_priv(br_dev);
rcu_read_lock();
f = br_fdb_find_rcu(br, addr, vid);
- if (f && f->dst)
- dev = f->dst->dev;
+ if (f) {
+ dst = READ_ONCE(f->dst);
+ if (dst)
+ dev = dst->dev;
+ }
rcu_read_unlock();
return dev;
@@ -346,7 +350,7 @@ static void fdb_delete_local(struct net_bridge *br,
vg = nbp_vlan_group(op);
if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
(!vid || br_vlan_find(vg, vid))) {
- f->dst = op;
+ WRITE_ONCE(f->dst, op);
clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
return;
}
@@ -357,7 +361,7 @@ static void fdb_delete_local(struct net_bridge *br,
/* Maybe bridge device has same hw addr? */
if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
(!vid || (v && br_vlan_should_use(v)))) {
- f->dst = NULL;
+ WRITE_ONCE(f->dst, NULL);
clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
return;
}
@@ -928,6 +932,7 @@ int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
int br_fdb_fillbuf(struct net_bridge *br, void *buf,
unsigned long maxnum, unsigned long skip)
{
+ const struct net_bridge_port *dst;
struct net_bridge_fdb_entry *f;
struct __fdb_entry *fe = buf;
unsigned long delta;
@@ -944,7 +949,8 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf,
continue;
/* ignore pseudo entry for local MAC address */
- if (!f->dst)
+ dst = READ_ONCE(f->dst);
+ if (!dst)
continue;
if (skip) {
@@ -956,8 +962,8 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf,
memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
/* due to ABI compat need to split into hi/lo */
- fe->port_no = f->dst->port_no;
- fe->port_hi = f->dst->port_no >> 8;
+ fe->port_no = dst->port_no;
+ fe->port_hi = dst->port_no >> 8;
fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags);
if (!test_bit(BR_FDB_STATIC, &f->flags)) {
@@ -1083,9 +1089,11 @@ int br_fdb_dump(struct sk_buff *skb,
rcu_read_lock();
hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
+ const struct net_bridge_port *dst = READ_ONCE(f->dst);
+
if (*idx < ctx->fdb_idx)
goto skip;
- if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
+ if (filter_dev && (!dst || dst->dev != filter_dev)) {
if (filter_dev != dev)
goto skip;
/* !f->dst is a special case for bridge
@@ -1093,10 +1101,10 @@ int br_fdb_dump(struct sk_buff *skb,
* Therefore need a little more filtering
* we only want to dump the !f->dst case
*/
- if (f->dst)
+ if (dst)
goto skip;
}
- if (!filter_dev && f->dst)
+ if (!filter_dev && dst)
goto skip;
err = fdb_fill_info(skb, br, f,
--
2.43.0
^ permalink raw reply related
* [PATCH net 1/1] 8021q: free cleared egress QoS mappings safely
From: Ren Wei @ 2026-04-13 9:07 UTC (permalink / raw)
To: netdev
Cc: andrew+netdev, davem, edumazet, kuba, pabeni, horms, kees,
yifanwucs, tomapufckgml, yuantan098, bird, ylong030, n05ec
In-Reply-To: <cover.1776039122.git.ylong030@ucr.edu>
From: Longxuan Yu <ylong030@ucr.edu>
vlan_dev_set_egress_priority() leaves cleared egress priority mapping
nodes in the hash until device teardown. Repeated set/clear cycles with
distinct skb priorities therefore allocate an unbounded number of
vlan_priority_tci_mapping objects and leak memory.
Delete mappings when vlan_prio is cleared instead of keeping
tombstones. The TX fast path and reporting paths walk the lists without
RTNL, so convert the egress mapping lists to RCU-protected pointers and
defer freeing removed nodes until after a grace period.
Cc: stable@kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Longxuan Yu <ylong030@ucr.edu>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
---
include/linux/if_vlan.h | 23 +++++++++++--------
net/8021q/vlan_dev.c | 48 +++++++++++++++++++++++-----------------
net/8021q/vlan_netlink.c | 9 +++-----
net/8021q/vlanproc.c | 12 ++++++----
4 files changed, 53 insertions(+), 39 deletions(-)
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index e6272f9c5e42..0a27533e70f3 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -151,7 +151,7 @@ extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
struct vlan_priority_tci_mapping {
u32 priority;
u16 vlan_qos;
- struct vlan_priority_tci_mapping *next;
+ struct vlan_priority_tci_mapping __rcu *next;
};
struct proc_dir_entry;
@@ -177,7 +177,7 @@ struct vlan_dev_priv {
unsigned int nr_ingress_mappings;
u32 ingress_priority_map[8];
unsigned int nr_egress_mappings;
- struct vlan_priority_tci_mapping *egress_priority_map[16];
+ struct vlan_priority_tci_mapping __rcu *egress_priority_map[16];
__be16 vlan_proto;
u16 vlan_id;
@@ -209,19 +209,24 @@ static inline u16
vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
{
struct vlan_priority_tci_mapping *mp;
+ u16 vlan_qos = 0;
- smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
+ rcu_read_lock();
- mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
+ mp = rcu_dereference(vlan_dev_priv(dev)->egress_priority_map[skprio & 0xF]);
while (mp) {
if (mp->priority == skprio) {
- return mp->vlan_qos; /* This should already be shifted
- * to mask correctly with the
- * VLAN's TCI */
+ vlan_qos = READ_ONCE(mp->vlan_qos);
+ break;
}
- mp = mp->next;
+ mp = rcu_dereference(mp->next);
}
- return 0;
+ rcu_read_unlock();
+
+ /* This should already be shifted to mask correctly with
+ * the VLAN's TCI.
+ */
+ return vlan_qos;
}
extern bool vlan_do_receive(struct sk_buff **skb);
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index c40f7d5c4fca..377616f51697 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -172,41 +172,43 @@ int vlan_dev_set_egress_priority(const struct net_device *dev,
u32 skb_prio, u16 vlan_prio)
{
- struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
- struct vlan_priority_tci_mapping *mp = NULL;
- struct vlan_priority_tci_mapping *np;
- u32 vlan_qos = (vlan_prio << VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK;
+ struct vlan_priority_tci_mapping __rcu **mpp;
+ struct vlan_priority_tci_mapping *mp;
+ struct vlan_priority_tci_mapping *np;
+ struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
+ u32 bucket = skb_prio & 0xF;
+ u32 vlan_qos = (vlan_prio << VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK;
/* See if a priority mapping exists.. */
- mp = vlan->egress_priority_map[skb_prio & 0xF];
+ mpp = &vlan->egress_priority_map[bucket];
+ mp = rtnl_dereference(*mpp);
while (mp) {
if (mp->priority == skb_prio) {
- if (mp->vlan_qos && !vlan_qos)
+ if (!vlan_qos) {
+ rcu_assign_pointer(*mpp, rtnl_dereference(mp->next));
vlan->nr_egress_mappings--;
- else if (!mp->vlan_qos && vlan_qos)
- vlan->nr_egress_mappings++;
- mp->vlan_qos = vlan_qos;
+ kfree_rcu_mightsleep(mp);
+ } else {
+ WRITE_ONCE(mp->vlan_qos, vlan_qos);
+ }
return 0;
}
- mp = mp->next;
+ mpp = &mp->next;
+ mp = rtnl_dereference(*mpp);
}
/* Create a new mapping then. */
- mp = vlan->egress_priority_map[skb_prio & 0xF];
+ if (!vlan_qos)
+ return 0;
+
np = kmalloc_obj(struct vlan_priority_tci_mapping);
if (!np)
return -ENOBUFS;
- np->next = mp;
np->priority = skb_prio;
np->vlan_qos = vlan_qos;
- /* Before inserting this element in hash table, make sure all its fields
- * are committed to memory.
- * coupled with smp_rmb() in vlan_dev_get_egress_qos_mask()
- */
- smp_wmb();
- vlan->egress_priority_map[skb_prio & 0xF] = np;
- if (vlan_qos)
- vlan->nr_egress_mappings++;
+ RCU_INIT_POINTER(np->next, rtnl_dereference(vlan->egress_priority_map[bucket]));
+ rcu_assign_pointer(vlan->egress_priority_map[bucket], np);
+ vlan->nr_egress_mappings++;
return 0;
}
@@ -604,11 +606,17 @@ void vlan_dev_free_egress_priority(const struct net_device *dev)
int i;
for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) {
- while ((pm = vlan->egress_priority_map[i]) != NULL) {
- vlan->egress_priority_map[i] = pm->next;
- kfree(pm);
+ pm = rtnl_dereference(vlan->egress_priority_map[i]);
+ RCU_INIT_POINTER(vlan->egress_priority_map[i], NULL);
+ while (pm) {
+ struct vlan_priority_tci_mapping *next;
+
+ next = rtnl_dereference(pm->next);
+ kfree_rcu_mightsleep(pm);
+ pm = next;
}
}
+ vlan->nr_egress_mappings = 0;
}
static void vlan_dev_uninit(struct net_device *dev)
diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
index a000b1ef0520..bbe7cbd97939 100644
--- a/net/8021q/vlan_netlink.c
+++ b/net/8021q/vlan_netlink.c
@@ -260,13 +260,10 @@ static int vlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
goto nla_put_failure;
for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) {
- for (pm = vlan->egress_priority_map[i]; pm;
- pm = pm->next) {
- if (!pm->vlan_qos)
- continue;
-
+ for (pm = rtnl_dereference(vlan->egress_priority_map[i]); pm;
+ pm = rtnl_dereference(pm->next)) {
m.from = pm->priority;
- m.to = (pm->vlan_qos >> 13) & 0x7;
+ m.to = (READ_ONCE(pm->vlan_qos) >> 13) & 0x7;
if (nla_put(skb, IFLA_VLAN_QOS_MAPPING,
sizeof(m), &m))
goto nla_put_failure;
diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c
index fa67374bda49..0e424e0895b7 100644
--- a/net/8021q/vlanproc.c
+++ b/net/8021q/vlanproc.c
@@ -262,15 +262,19 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset)
vlan->ingress_priority_map[7]);
seq_printf(seq, " EGRESS priority mappings: ");
+ rcu_read_lock();
for (i = 0; i < 16; i++) {
- const struct vlan_priority_tci_mapping *mp
- = vlan->egress_priority_map[i];
+ const struct vlan_priority_tci_mapping *mp =
+ rcu_dereference(vlan->egress_priority_map[i]);
while (mp) {
+ u16 vlan_qos = READ_ONCE(mp->vlan_qos);
+
seq_printf(seq, "%u:%d ",
- mp->priority, ((mp->vlan_qos >> 13) & 0x7));
- mp = mp->next;
+ mp->priority, ((vlan_qos >> 13) & 0x7));
+ mp = rcu_dereference(mp->next);
}
}
+ rcu_read_unlock();
seq_puts(seq, "\n");
return 0;
--
2.43.0
^ permalink raw reply related
* Re: [patch 14/38] slub: Use prandom instead of get_cycles()
From: Harry Yoo (Oracle) @ 2026-04-13 9:07 UTC (permalink / raw)
To: Thomas Gleixner
Cc: LKML, Vlastimil Babka, linux-mm, Arnd Bergmann, x86, Lu Baolu,
iommu, Michael Grzeschik, netdev, linux-wireless, Herbert Xu,
linux-crypto, David Woodhouse, Bernie Thompson, linux-fbdev,
Theodore Tso, linux-ext4, Andrew Morton, Uladzislau Rezki,
Marco Elver, Dmitry Vyukov, kasan-dev, Andrey Ryabinin,
Thomas Sailer, linux-hams, Jason A. Donenfeld, Richard Henderson,
linux-alpha, Russell King, linux-arm-kernel, Catalin Marinas,
Huacai Chen, loongarch, Geert Uytterhoeven, linux-m68k,
Dinh Nguyen, Jonas Bonn, linux-openrisc, Helge Deller,
linux-parisc, Michael Ellerman, linuxppc-dev, Paul Walmsley,
linux-riscv, Heiko Carstens, linux-s390, David S. Miller,
sparclinux, Hao Li, Christoph Lameter, David Rientjes,
Roman Gushchin, Shengming Hu
In-Reply-To: <20260410120318.525653921@kernel.org>
[Resending after fixing broken email headers]
On Fri, Apr 10, 2026 at 02:19:37PM +0200, Thomas Gleixner wrote:
> The decision whether to scan remote nodes is based on a 'random' number
> retrieved via get_cycles(). get_cycles() is about to be removed.
>
> There is already prandom state in the code, so use that instead.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Vlastimil Babka <vbabka@kernel.org>
> Cc: linux-mm@kvack.org
> ---
Acked-by: Harry Yoo (Oracle) <harry@kernel.org>
Is this for this merge window?
This may conflict with upcoming changes on freelist shuffling [1]
(not queued for slab/for-next yet though), but it should be easy to
resolve.
[Cc'ing Shengming and SLAB ALLOCATOR folks]
[1] https://lore.kernel.org/linux-mm/20260409204352095kKWVYKtZImN59ybO6iRNj@zte.com.cn
--
Cheers,
Harry / Hyeonggon
> mm/slub.c | 37 +++++++++++++++++++++++--------------
> 1 file changed, 23 insertions(+), 14 deletions(-)
>
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -3302,6 +3302,25 @@ static inline struct slab *alloc_slab_pa
> return slab;
> }
>
> +#if defined(CONFIG_SLAB_FREELIST_RANDOM) || defined(CONFIG_NUMA)
> +static DEFINE_PER_CPU(struct rnd_state, slab_rnd_state);
> +
> +static unsigned int slab_get_prandom_state(unsigned int limit)
> +{
> + struct rnd_state *state;
> + unsigned int res;
> +
> + /*
> + * An interrupt or NMI handler might interrupt and change
> + * the state in the middle, but that's safe.
> + */
> + state = &get_cpu_var(slab_rnd_state);
> + res = prandom_u32_state(state) % limit;
> + put_cpu_var(slab_rnd_state);
> + return res;
> +}
> +#endif
> +
> #ifdef CONFIG_SLAB_FREELIST_RANDOM
> /* Pre-initialize the random sequence cache */
> static int init_cache_random_seq(struct kmem_cache *s)
> @@ -3365,8 +3384,6 @@ static void *next_freelist_entry(struct
> return (char *)start + idx;
> }
>
> -static DEFINE_PER_CPU(struct rnd_state, slab_rnd_state);
> -
> /* Shuffle the single linked freelist based on a random pre-computed sequence */
> static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab,
> bool allow_spin)
> @@ -3383,15 +3400,7 @@ static bool shuffle_freelist(struct kmem
> if (allow_spin) {
> pos = get_random_u32_below(freelist_count);
> } else {
> - struct rnd_state *state;
> -
> - /*
> - * An interrupt or NMI handler might interrupt and change
> - * the state in the middle, but that's safe.
> - */
> - state = &get_cpu_var(slab_rnd_state);
> - pos = prandom_u32_state(state) % freelist_count;
> - put_cpu_var(slab_rnd_state);
> + pos = slab_get_prandom_state(freelist_count);
> }
>
> page_limit = slab->objects * s->size;
> @@ -3882,7 +3891,7 @@ static void *get_from_any_partial(struct
> * with available objects.
> */
> if (!s->remote_node_defrag_ratio ||
> - get_cycles() % 1024 > s->remote_node_defrag_ratio)
> + slab_get_prandom_state(1024) > s->remote_node_defrag_ratio)
> return NULL;
>
> do {
> @@ -7102,7 +7111,7 @@ static unsigned int
>
> /* see get_from_any_partial() for the defrag ratio description */
> if (!s->remote_node_defrag_ratio ||
> - get_cycles() % 1024 > s->remote_node_defrag_ratio)
> + slab_get_prandom_state(1024) > s->remote_node_defrag_ratio)
> return 0;
>
> do {
> @@ -8421,7 +8430,7 @@ void __init kmem_cache_init_late(void)
> flushwq = alloc_workqueue("slub_flushwq", WQ_MEM_RECLAIM | WQ_PERCPU,
> 0);
> WARN_ON(!flushwq);
> -#ifdef CONFIG_SLAB_FREELIST_RANDOM
> +#if defined(CONFIG_SLAB_FREELIST_RANDOM) || defined(CONFIG_NUMA)
> prandom_init_once(&slab_rnd_state);
> #endif
> }
>
>
^ permalink raw reply
* [PATCH] rose: Fix rose_find_socket() returning without sock_hold()
From: Dudu Lu @ 2026-04-13 9:04 UTC (permalink / raw)
To: netdev; +Cc: davem, edumazet, kuba, pabeni, Dudu Lu
rose_find_socket() returns a raw socket pointer after releasing
rose_list_lock. The socket can be freed by a concurrent close()
between the unlock and the caller's use of the pointer, leading
to a use-after-free.
Add sock_hold() before returning the found socket, and update
callers to sock_put() when done.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/rose/af_rose.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index ba56213e0a2a..b32b136f80aa 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1,4 +1,5 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
+ if (s)
+ sock_hold(s);// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* [PATCH] nfc: llcp: Fix TLV parsing off-by-one in LLCP connect and SNL
From: Dudu Lu @ 2026-04-13 9:02 UTC (permalink / raw)
To: netdev; +Cc: davem, edumazet, kuba, pabeni, Dudu Lu
The TLV parsing loops in nfc_llcp_connect_sn() and
nfc_llcp_recv_snl() check `offset < tlv_array_len` before accessing
both tlv[0] (type) and tlv[1] (length). When exactly one byte remains
(offset == tlv_array_len - 1), the access to tlv[1] reads one byte
beyond the skb data buffer.
Fix both sites by changing the loop condition to
`offset + 1 < tlv_array_len`, ensuring at least 2 bytes are available
before reading the type and length fields.
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/nfc/llcp_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
index 366d7566308c..d1a75b9445e1 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -852,7 +852,7 @@ static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
const u8 *tlv = &skb->data[2];
size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
- while (offset < tlv_array_len) {
+ while (offset + 1 < tlv_array_len) {
type = tlv[0];
length = tlv[1];
@@ -1297,7 +1297,7 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
offset = 0;
sdres_tlvs_len = 0;
- while (offset < tlv_len) {
+ while (offset + 1 < tlv_len) {
type = tlv[0];
length = tlv[1];
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* Re: [PATCH v2 2/2] MAINTAINERS: update PTP maintainer entries after directory split
From: Wen Gu @ 2026-04-13 9:00 UTC (permalink / raw)
To: Jakub Kicinski, David Woodhouse
Cc: tglx, richardcochran, andrew+netdev, davem, edumazet, pabeni,
linux-kernel, netdev, jstultz, anna-maria, frederic,
daniel.lezcano, sboyd, vladimir.oltean, wei.fang, xiaoning.wang,
jonathan.lemon, vadim.fedorenko, yangbo.lu, svens, nick.shi,
ajay.kaher, alexey.makhalov, bcm-kernel-feedback-list, linux-fpga,
imx, linux-s390, dust.li, xuanzhuo, mani, imran.shaik, taniya.das
In-Reply-To: <20260412095301.4fe1fe65@kernel.org>
On 2026/4/13 00:53, Jakub Kicinski wrote:
> On Sun, 12 Apr 2026 17:32:22 +0100 David Woodhouse wrote:
>> On 12 April 2026 16:47:04 BST, Jakub Kicinski <kuba@kernel.org> wrote:
>>> On Tue, 7 Apr 2026 18:48:02 +0800 Wen Gu wrote:
>>>> +PTP EMULATED CLOCK SUPPORT
>>>> +M: David Woodhouse <dwmw2@infradead.org>
>>>> +M: Wen Gu <guwen@linux.alibaba.com>
>>>> +M: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>>>> +L: linux-kernel@vger.kernel.org
>>>> +S: Maintained
>>>> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core
>>>
>>> Hi David,
>>>
>>> Do you have a tree to route the patches thru? Or do you really have
>>> access to the tip tree?
>>
>> I do not have access to the tip tree. I can make a shared tree on
>> git.infradead.org if the other two maintainers would like to send me
>> a SSH pubkey and preferred username...
>
> Honestly I'd love for you to be the only M here, and the other two
> to be reviewers. Xuan Zhuo is currently at v40 trying to upstream
> an Ethernet driver. Some growth needed there to become a subsystem
> maintainer IMO.
Hi Jakub, David,
That works for us. We can act as reviewers.
If David sets up a new tree, I will update the MAINTAINERS entry
accordingly in v3.
Thanks.
^ permalink raw reply
* Re: [patch 14/38] slub: Use prandom instead of get_cycles()
From: Vlastimil Babka (SUSE) @ 2026-04-13 9:00 UTC (permalink / raw)
To: Thomas Gleixner, LKML
Cc: linux-mm, Arnd Bergmann, x86, Lu Baolu, iommu, Michael Grzeschik,
netdev, linux-wireless, Herbert Xu, linux-crypto, David Woodhouse,
Bernie Thompson, linux-fbdev, Theodore Tso, linux-ext4,
Andrew Morton, Uladzislau Rezki, Marco Elver, Dmitry Vyukov,
kasan-dev, Andrey Ryabinin, Thomas Sailer, linux-hams,
Jason A. Donenfeld, Richard Henderson, linux-alpha, Russell King,
linux-arm-kernel, Catalin Marinas, Huacai Chen, loongarch,
Geert Uytterhoeven, linux-m68k, Dinh Nguyen, Jonas Bonn,
linux-openrisc, Helge Deller, linux-parisc, Michael Ellerman,
linuxppc-dev, Paul Walmsley, linux-riscv, Heiko Carstens,
linux-s390, David S. Miller, sparclinux, Harry Yoo (Oracle),
Hao Li
In-Reply-To: <20260410120318.525653921@kernel.org>
On 4/10/26 14:19, Thomas Gleixner wrote:
> The decision whether to scan remote nodes is based on a 'random' number
> retrieved via get_cycles(). get_cycles() is about to be removed.
>
> There is already prandom state in the code, so use that instead.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Vlastimil Babka <vbabka@kernel.org>
> Cc: linux-mm@kvack.org
LGTM.
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
^ permalink raw reply
* [PATCH] nfc: nci: Add skb length validation in nci_core_init_rsp_packet
From: Dudu Lu @ 2026-04-13 9:01 UTC (permalink / raw)
To: netdev; +Cc: davem, edumazet, kuba, pabeni, Dudu Lu
nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() cast
skb->data to response structures and dereference fields without first
checking that skb->len is large enough. A malicious or malformed NFCC
can send a short response packet, causing an out-of-bounds read.
Add minimum length checks at the start of both functions. For v1, check
that at least sizeof(nci_core_init_rsp_1) bytes are available before
accessing rsp_1 fields, and validate the dynamic offset before accessing
rsp_2. For v2, check that at least sizeof(nci_core_init_rsp_nci_ver2)
bytes are available.
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/nfc/nci/rsp.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c
index 9eeb862825c5..01972c806b45 100644
--- a/net/nfc/nci/rsp.c
+++ b/net/nfc/nci/rsp.c
@@ -1,3 +1,14 @@
+ if (skb->len < sizeof(*rsp)) {
+ pr_err("short NCI_CORE_INIT_RSP v2 packet\n");
+ return NCI_STATUS_SYNTAX_ERROR;
+ }
+ if (skb->len < 6 + rsp_1->num_supported_rf_interfaces +
+ sizeof(*rsp_2)) {
+ pr_err("short NCI_CORE_INIT_RSP v1 packet\n");
+ return NCI_STATUS_SYNTAX_ERROR;
+ }
+ if (skb->len < sizeof(*rsp_1))
+ return NCI_STATUS_SYNTAX_ERROR;
// SPDX-License-Identifier: GPL-2.0-only
/*
* The NFC Controller Interface is the communication protocol between an
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* [PATCH] tipc: Ensure NUL-termination of remote algorithm name
From: Dudu Lu @ 2026-04-13 8:58 UTC (permalink / raw)
To: netdev; +Cc: jmaloy, Dudu Lu
In tipc_crypto_key_rcv(), the algorithm name is copied from the incoming
message using memcpy with a fixed size of TIPC_AEAD_ALG_NAME (32 bytes).
If the remote peer sends a name that fills all 32 bytes without a NUL
terminator, the alg_name field will not be NUL-terminated. This string
is later passed to crypto_alloc_aead() which expects a NUL-terminated
string, potentially causing an out-of-bounds read when the crypto
subsystem searches for the algorithm by name.
Fix by explicitly NUL-terminating the last byte of alg_name after the
memcpy.
Fixes: 1ef6f7c9390f ("tipc: add automatic session key exchange")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/tipc/crypto.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
index d3046a39ff72..ac072356bf0c 100644
--- a/net/tipc/crypto.c
+++ b/net/tipc/crypto.c
@@ -2325,6 +2325,7 @@ static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr)
/* Copy key from msg data */
skey->keylen = keylen;
memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME);
+ skey->alg_name[TIPC_AEAD_ALG_NAME - 1] = '\0';
memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32),
skey->keylen);
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* [PATCH] macvlan: fix macvlan_get_size() not reserving space for IFLA_MACVLAN_BC_CUTOFF
From: Dudu Lu @ 2026-04-13 8:53 UTC (permalink / raw)
To: netdev; +Cc: andrew+netdev, davem, edumazet, kuba, pabeni, Dudu Lu
macvlan_get_size() does not account for IFLA_MACVLAN_BC_CUTOFF, but
macvlan_fill_info() conditionally includes it when port->bc_cutoff != 1.
This causes nla_put_s32() to fail with -EMSGSIZE when the netlink skb
runs out of space, triggering a WARN_ON in rtnetlink and preventing the
interface from being dumped.
The bug can be reproduced with:
ip link add macvlan0 link eth0 type macvlan mode bridge
ip link set macvlan0 type macvlan bc_cutoff 0
ip -d link show macvlan0 # fails with -EMSGSIZE
The bc_cutoff feature was added in commit 954d1fa1ac93 ("macvlan: Add
netlink attribute for broadcast cutoff"), which added the nla_put_s32()
call in macvlan_fill_info() but missed adding the corresponding
nla_total_size(4) in macvlan_get_size(). A follow-up commit
55cef78c244d ("macvlan: add forgotten nla_policy for
IFLA_MACVLAN_BC_CUTOFF") fixed the missing nla_policy entry but still
did not fix the size calculation.
Fixes: 954d1fa1ac93 ("macvlan: Add netlink attribute for broadcast cutoff")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
drivers/net/macvlan.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index a71f058eceef..80f87599a503 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1681,6 +1681,7 @@ static size_t macvlan_get_size(const struct net_device *dev)
+ macvlan_get_size_mac(vlan) /* IFLA_MACVLAN_MACADDR */
+ nla_total_size(4) /* IFLA_MACVLAN_BC_QUEUE_LEN */
+ nla_total_size(4) /* IFLA_MACVLAN_BC_QUEUE_LEN_USED */
+ + nla_total_size(4) /* IFLA_MACVLAN_BC_CUTOFF */
);
}
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* [PATCH] vsock/virtio: fix accept queue count leak on transport mismatch in recv_listen
From: Dudu Lu @ 2026-04-13 8:52 UTC (permalink / raw)
To: netdev; +Cc: stefanha, sgarzare, mst, jasowang, Dudu Lu
virtio_transport_recv_listen() calls sk_acceptq_added(sk) to increment
the listener's accept queue counter before calling
vsock_assign_transport(). When vsock_assign_transport() fails or selects
a different transport than the one that received the packet, the error
path returns without calling sk_acceptq_removed(sk), permanently
incrementing sk_ack_backlog.
A malicious VM peer can exploit this by sending repeated CONNECT
requests that trigger the transport mismatch condition. Each such
request permanently increments sk_ack_backlog. After approximately
backlog+1 such requests (default backlog ~128), sk_acceptq_is_full()
returns true, causing the listener to reject ALL new connections with
-ENOMEM. The only recovery is closing and re-creating the listener
socket.
Compare with vmci_transport.c and hyperv_transport.c which correctly
place sk_acceptq_added() AFTER the transport check, avoiding this
issue entirely.
Fix by moving sk_acceptq_added(sk) to after the transport validation
check, matching the pattern used by the other transports.
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/vmw_vsock/virtio_transport_common.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 8a9fb23c6e85..29e1d9833be4 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1,3 +1,4 @@
+ sk_acceptq_added(sk);
// SPDX-License-Identifier: GPL-2.0-only
/*
* common code for virtio vsock
@@ -1560,8 +1561,9 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
return -ENOMEM;
}
- sk_acceptq_added(sk);
+
+ sk_acceptq_added(sk);
lock_sock_nested(child, SINGLE_DEPTH_NESTING);
child->sk_state = TCP_ESTABLISHED;
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* [PATCH] net: dsa: sja1105: fix division by zero in sja1105_tas_set_runtime_params()
From: Alexander.Chesnokov @ 2026-04-13 8:51 UTC (permalink / raw)
To: olteanv
Cc: lvc-project, Oleg.Kazakov, Pavel.Zhigulin, Alexander Chesnokov,
stable, Andrew Lunn, Florian Fainelli, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel, netdev
From: Alexander Chesnokov <Alexander.Chesnokov@kaspersky.com>
If taprio offload is configured such that none of the ports' base_time
is less than S64_MAX (the initial value of earliest_base_time), then
its_cycle_time remains zero and is passed to future_base_time() as
cycle_time, causing division by zero in div_s64().
Add a check for its_cycle_time being zero before calling
future_base_time() and return -EINVAL.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 86db36a347b4 ("net: dsa: sja1105: Implement state machine for TAS with PTP clock source")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Chesnokov <Alexander.Chesnokov@kaspersky.com>
---
drivers/net/dsa/sja1105/sja1105_tas.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/net/dsa/sja1105/sja1105_tas.c b/drivers/net/dsa/sja1105/sja1105_tas.c
index e6153848a950..ce4b544a2b9c 100644
--- a/drivers/net/dsa/sja1105/sja1105_tas.c
+++ b/drivers/net/dsa/sja1105/sja1105_tas.c
@@ -62,6 +62,9 @@ static int sja1105_tas_set_runtime_params(struct sja1105_private *priv)
if (!tas_data->enabled)
return 0;
+ if (!its_cycle_time)
+ return -EINVAL;
+
/* Roll the earliest base time over until it is in a comparable
* time base with the latest, then compare their deltas.
* We want to enforce that all ports' base times are within
--
2.43.0
^ permalink raw reply related
* [PATCH] xfrm: iptfs: fix deadlock in iptfs_destroy_state
From: Dudu Lu @ 2026-04-13 8:51 UTC (permalink / raw)
To: netdev; +Cc: steffen.klassert, herbert, davem, Dudu Lu
iptfs_destroy_state() acquires x->lock (spin_lock_bh) and then calls
hrtimer_cancel(&xtfs->iptfs_timer). The timer callback
iptfs_delay_timer() also acquires x->lock (spin_lock). If the timer
fires on another CPU during destroy, hrtimer_cancel() waits for the
callback to complete, but the callback is blocked trying to acquire
the same lock — a classic ABBA deadlock.
The same pattern exists for drop_timer: destroy holds drop_lock and
calls hrtimer_cancel(&xtfs->drop_timer), while iptfs_drop_timer()
also acquires drop_lock.
Fix by cancelling the timers before acquiring the locks. The timer
callbacks check for state validity, so a late cancel is safe. The
queue splice is still done under the lock for consistency.
Fixes: 4b3faf610cc6 ("xfrm: iptfs: add new iptfs xfrm mode impl")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/xfrm/xfrm_iptfs.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 97bc979e55ba..11291b87158c 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -2708,8 +2708,10 @@ static void iptfs_destroy_state(struct xfrm_state *x)
if (!xtfs)
return;
- spin_lock_bh(&xtfs->x->lock);
hrtimer_cancel(&xtfs->iptfs_timer);
+ hrtimer_cancel(&xtfs->drop_timer);
+
+ spin_lock_bh(&xtfs->x->lock);
__skb_queue_head_init(&list);
skb_queue_splice_init(&xtfs->queue, &list);
spin_unlock_bh(&xtfs->x->lock);
@@ -2717,9 +2719,7 @@ static void iptfs_destroy_state(struct xfrm_state *x)
while ((skb = __skb_dequeue(&list)))
kfree_skb(skb);
- spin_lock_bh(&xtfs->drop_lock);
- hrtimer_cancel(&xtfs->drop_timer);
- spin_unlock_bh(&xtfs->drop_lock);
+ /* drop_timer already cancelled above */
if (xtfs->ra_newskb)
kfree_skb(xtfs->ra_newskb);
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* [PATCH] net/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir
From: Dudu Lu @ 2026-04-13 8:49 UTC (permalink / raw)
To: netdev; +Cc: jhs, jiri, Dudu Lu
In tcf_blockcast_redir(), when iterating block ports to redirect
packets to multiple devices, the mac_header_xmit flag is queried
from the wrong device. The loop sends to dev_prev but queries
dev_is_mac_header_xmit(dev) — which is the NEXT device in the
iteration, not the one being sent to.
This causes tcf_mirred_to_dev() to make incorrect decisions about
whether to push or pull the MAC header. When the block contains
mixed device types (e.g., an ethernet veth and a tunnel device),
intermediate devices get the wrong mac_header_xmit flag, leading to
skb header corruption. In the worst case, skb_push_rcsum with an
incorrect mac_len can exhaust headroom and panic.
The last device in the loop is handled correctly (line 365-366 uses
dev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste
oversight for the intermediate devices.
Fix by using dev_prev instead of dev for the mac_header_xmit query,
consistent with the device actually being sent to.
Fixes: 42f39036cda8 ("net/sched: act_mirred: Allow mirred to block")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/sched/act_mirred.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 05e0b14b5773..2c5a7a321a94 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -354,7 +354,7 @@ static int tcf_blockcast_redir(struct sk_buff *skb, struct tcf_mirred *m,
goto assign_prev;
tcf_mirred_to_dev(skb, m, dev_prev,
- dev_is_mac_header_xmit(dev),
+ dev_is_mac_header_xmit(dev_prev),
mirred_eaction, retval);
assign_prev:
dev_prev = dev;
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
* Re: [PATCH net-next v4 5/5] selftests: net: bridge: add MRC and QQIC field encoding tests
From: Ido Schimmel @ 2026-04-13 8:47 UTC (permalink / raw)
To: Ujjal Roy
Cc: David S . Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Simon Horman, Nikolay Aleksandrov, David Ahern, Shuah Khan,
Andy Roulin, Yong Wang, Petr Machata, Ujjal Roy, bridge, netdev,
linux-kernel, linux-kselftest
In-Reply-To: <20260412111047.1326-6-royujjal@gmail.com>
See some comments below, but note that net-next is closed:
https://lore.kernel.org/netdev/20260412142250.131bf997@kernel.org/
So you can either wait with v5 until it is open again or post it as RFC
so that we can at least review (but not merge) it while net-next is
closed.
On Sun, Apr 12, 2026 at 11:10:47AM +0000, Ujjal Roy wrote:
> Enhance vlmc_query_intvl_test and vlmc_query_response_intvl_test in
> bridge_vlan_mcast.sh to validate IGMPv3/MLDv2 protocol compliance for
> MRC and QQIC field encoding across both linear and exponential ranges.
>
> TEST: Vlan multicast snooping enable [ OK ]
> TEST: Vlan mcast_query_interval global option default value [ OK ]
> INFO: Vlan 10 mcast_query_interval (QQIC) test cases:
> TEST: Number of tagged IGMPv2 general query [ OK ]
> TEST: IGMPv3 QQIC linear value 60 [ OK ]
> TEST: MLDv2 QQIC linear value 60 [ OK ]
> TEST: IGMPv3 QQIC non linear value 160 [ OK ]
> TEST: MLDv2 QQIC non linear value 160 [ OK ]
> TEST: Vlan mcast_query_response_interval global option default value [ OK ]
> INFO: Vlan 10 mcast_query_response_interval (MRC) test cases:
> TEST: IGMPv3 MRC linear value 60 [ OK ]
> TEST: IGMPv3 MRC non linear value 160 [ OK ]
> TEST: MLDv2 MRC linear value 30000 [ OK ]
> TEST: MLDv2 MRC non linear value 60000 [ OK ]
>
> Signed-off-by: Ujjal Roy <royujjal@gmail.com>
> ---
> .../net/forwarding/bridge_vlan_mcast.sh | 150 +++++++++++++++++-
> 1 file changed, 142 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/net/forwarding/bridge_vlan_mcast.sh b/tools/testing/selftests/net/forwarding/bridge_vlan_mcast.sh
> index e8031f68200a..9f9f33d58286 100755
> --- a/tools/testing/selftests/net/forwarding/bridge_vlan_mcast.sh
> +++ b/tools/testing/selftests/net/forwarding/bridge_vlan_mcast.sh
> @@ -162,14 +162,27 @@ vlmc_query_cnt_setup()
> {
> local type=$1
> local dev=$2
> + local match=$3
>
> if [[ $type == "igmp" ]]; then
> - tc filter add dev $dev egress pref 10 prot 802.1Q \
> + # This matches: IP Protocol 2 (IGMP)
> + tc filter add dev "$dev" egress pref 10 prot 802.1Q \
> flower vlan_id 10 vlan_ethtype ipv4 dst_ip 224.0.0.1 ip_proto 2 \
> + action continue
> + # AND Type 0x11 (Query) at offset 24 after IP
> + # IP (20 byte IP + 4 bytes Option)
Let's make it clearer: 20 bytes IPv4 header + 4 bytes Router Alert option
> + match=(match u8 0x11 0xff at 24 $match)
> + tc filter add dev "$dev" egress pref 20 prot 802.1Q u32 "${match[@]}" \
> action pass
> else
> - tc filter add dev $dev egress pref 10 prot 802.1Q \
> + # This matches: ICMPv6
> + tc filter add dev "$dev" egress pref 10 prot 802.1Q \
> flower vlan_id 10 vlan_ethtype ipv6 dst_ip ff02::1 ip_proto icmpv6 \
> + action continue
> + # AND Type 0x82 (Query) at offset 48 after IPv6
> + # IPv6 (40 bytes IPv6 + 2 bytes next HDR + 4 bytes Option + 2 byte pad)
Same: 40 bytes IPv6 header + 8 bytes Hop-by-hop option
> + match=(match u8 0x82 0xff at 48 $match)
> + tc filter add dev "$dev" egress pref 20 prot 802.1Q u32 "${match[@]}" \
> action pass
> fi
Sashiko has a relevant comment:
"
Does this configuration evaluate all packets against the pref 20 filter,
regardless of the pref 10 result?
In tc, if a packet does not match a filter, classification automatically falls
through to the next priority filter. By using "action continue" on pref 10,
matching packets are also instructed to continue evaluation at the next filter.
Because both matching and non-matching packets proceed to pref 20, pref 10
seems to act as a no-op gate. Could this cause the u32 rules in pref 20 to
inadvertently match unrelated background traffic on the interface?
To implement a logical AND across different classifiers, should pref 10 use
"action goto chain 1" with pref 20 placed inside chain 1?
"
>
> @@ -181,7 +194,53 @@ vlmc_query_cnt_cleanup()
> local dev=$1
>
> ip link set dev br0 type bridge mcast_stats_enabled 0
> - tc filter del dev $dev egress pref 10
> + tc filter del dev "$dev" egress pref 20
> + tc filter del dev "$dev" egress pref 10
> +}
> +
> +vlmc_query_get_intvl_match()
> +{
> + local type=$1
> + local version=$2
> + local test=$3
> + local interval=$4
> +
> + if [ "$test" = "qqic" ]; then
> + # QQIC is 8-bit floating point encoding for IGMPv3 and MLDv2
> + if [ "${type}v${version}" = "igmpv3" ]; then
> + # IP 20 bytes + 4 bytes Option + IGMPv3[9]
> + if [[ $interval -lt 128 ]]; then
> + echo "match u8 0x3c 0xff at 33"
Please pass the expected value as an argument instead of hard coding
"0x3c" here. Same in other places in the function.
> + else
> + echo "match u8 0x84 0xff at 33"
> + fi
> + elif [ "${type}v${version}" = "mldv2" ]; then
> + # IPv6 40 + 2 next HDR + 4 Option + 2 pad + MLDv2[25]
> + if [[ $interval -lt 128 ]]; then
> + echo "match u8 0x3c 0xff at 73"
> + else
> + echo "match u8 0x84 0xff at 73"
> + fi
> + fi
> + elif [ "$test" = "mrc" ]; then
> + if [ "${type}v${version}" = "igmpv3" ]; then
> + # MRC is 8-bit floating point encoding for IGMPv3
> + # IP 20 bytes + 4 bytes Option + IGMPv3[1]
> + if [[ $interval -lt 128 ]]; then
> + echo "match u8 0x3c 0xff at 25"
> + else
> + echo "match u8 0x84 0xff at 25"
> + fi
> + elif [ "${type}v${version}" = "mldv2" ]; then
> + # MRC is 16-bit floating point encoding for MLDv2
> + # IPv6 40 + 2 next HDR + 4 Option + 2 pad + MLDv2[4]
> + if [[ $interval -lt 32768 ]]; then
> + echo "match u16 0x7530 0xffff at 52"
> + else
> + echo "match u16 0x8d4c 0xffff at 52"
> + fi
> + fi
> + fi
> }
>
> vlmc_check_query()
> @@ -191,9 +250,13 @@ vlmc_check_query()
> local dev=$3
> local expect=$4
> local time=$5
> + local test=$6
> + local interval=$7
> + local intvl_match=""
> local ret=0
>
> - vlmc_query_cnt_setup $type $dev
> + intvl_match="$(vlmc_query_get_intvl_match "$type" "$version" "$test" "$interval")"
> + vlmc_query_cnt_setup "$type" "$dev" "$intvl_match"
>
> local pre_tx_xstats=$(vlmc_query_cnt_xstats $type $version $dev)
> bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_querier 1
> @@ -201,7 +264,7 @@ vlmc_check_query()
> if [[ $ret -eq 0 ]]; then
> sleep $time
>
> - local tcstats=$(tc_rule_stats_get $dev 10 egress)
> + local tcstats=$(tc_rule_stats_get "$dev" 20 egress)
> local post_tx_xstats=$(vlmc_query_cnt_xstats $type $version $dev)
>
> if [[ $tcstats != $expect || \
> @@ -441,6 +504,7 @@ vlmc_query_intvl_test()
> check_err $? "Wrong default mcast_query_interval global vlan option value"
> log_test "Vlan mcast_query_interval global option default value"
>
> + log_info "Vlan 10 mcast_query_interval (QQIC) test cases:"
Let's remove this as it makes the output confusing:
INFO: Vlan 10 mcast_query_response_interval (MRC) test cases:
TEST: IGMPv3 MRC linear value 60 [ OK ]
[...]
TEST: Flood unknown vlan multicast packets to router port only [ OK ]
TEST: Disable multicast vlan snooping when vlan filtering is disabled [ OK ]
> RET=0
> bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_startup_query_count 0
> bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_interval 200
> @@ -448,8 +512,42 @@ vlmc_query_intvl_test()
> # 1 is sent immediately, then 2 more in the next 5 seconds
> vlmc_check_query igmp 2 $swp1 3 5
> check_err $? "Wrong number of tagged IGMPv2 general queries sent"
> - log_test "Vlan 10 mcast_query_interval option changed to 200"
> + log_test "Number of tagged IGMPv2 general query"
>
> + RET=0
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_igmp_version 3
> + check_err $? "Could not set mcast_igmp_version in vlan 10"
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_mld_version 2
> + check_err $? "Could not set mcast_mld_version in vlan 10"
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_interval 6000
> + check_err $? "Could not set mcast_query_interval in vlan 10"
> + # 1 is sent immediately, IGMPv3 QQIC should match with linear value 60s
> + vlmc_check_query igmp 3 $swp1 1 1 qqic 60
> + check_err $? "Wrong QQIC in generated IGMPv3 general queries"
> + log_test "IGMPv3 QQIC linear value 60"
> +
> + RET=0
> + # 1 is sent immediately, MLDv2 QQIC should match with linear value 60s
> + vlmc_check_query mld 2 $swp1 1 1 qqic 60
> + check_err $? "Wrong QQIC in generated MLDv2 general queries"
> + log_test "MLDv2 QQIC linear value 60"
> +
> + RET=0
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_interval 16000
> + check_err $? "Could not set mcast_query_interval in vlan 10"
> + # 1 is sent immediately, IGMPv3 QQIC should match with non linear value 160s
> + vlmc_check_query igmp 3 $swp1 1 1 qqic 160
> + check_err $? "Wrong QQIC in generated IGMPv3 general queries"
> + log_test "IGMPv3 QQIC non linear value 160"
> +
> + RET=0
> + # 1 is sent immediately, MLDv2 QQIC should match with non linear value 160s
> + vlmc_check_query mld 2 $swp1 1 1 qqic 160
> + check_err $? "Wrong QQIC in generated MLDv2 general queries"
> + log_test "MLDv2 QQIC non linear value 160"
> +
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_igmp_version 2
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_mld_version 1
> bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_startup_query_count 2
> bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_interval 12500
> }
> @@ -468,11 +566,47 @@ vlmc_query_response_intvl_test()
> check_err $? "Wrong default mcast_query_response_interval global vlan option value"
> log_test "Vlan mcast_query_response_interval global option default value"
>
> + log_info "Vlan 10 mcast_query_response_interval (MRC) test cases:"
Same
> + RET=0
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_startup_query_count 0
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_igmp_version 3
> + check_err $? "Could not set mcast_igmp_version in vlan 10"
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 600
> + check_err $? "Could not set mcast_query_response_interval in vlan 10"
> + # 1 is sent immediately, IGMPv3 MRC should match with linear value 60 units of 1/10s
> + vlmc_check_query igmp 3 $swp1 1 1 mrc 60
> + check_err $? "Wrong MRC in generated IGMPv3 general queries"
> + log_test "IGMPv3 MRC linear value 60"
> +
> + RET=0
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 1600
> + check_err $? "Could not set mcast_query_response_interval in vlan 10"
> + # 1 is sent immediately, IGMPv3 MRC should match with non linear value 160 unit of 1/10s
> + vlmc_check_query igmp 3 $swp1 1 1 mrc 160
> + check_err $? "Wrong MRC in generated IGMPv3 general queries"
> + log_test "IGMPv3 MRC non linear value 160"
> +
> + RET=0
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_mld_version 2
> + check_err $? "Could not set mcast_mld_version in vlan 10"
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 3000
> + check_err $? "Could not set mcast_query_response_interval in vlan 10"
> + # 1 is sent immediately, MLDv2 MRC should match with linear value 30000(ms)
> + vlmc_check_query mld 2 $swp1 1 1 mrc 30000
> + check_err $? "Wrong MRC in generated MLDv2 general queries"
> + log_test "MLDv2 MRC linear value 30000"
> +
> RET=0
> - bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 200
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 6000
> check_err $? "Could not set mcast_query_response_interval in vlan 10"
> - log_test "Vlan 10 mcast_query_response_interval option changed to 200"
> + # 1 is sent immediately, MLDv2 MRC should match with non linear value 60000(ms)
> + vlmc_check_query mld 2 $swp1 1 1 mrc 60000
> + check_err $? "Wrong MRC in generated MLDv2 general queries"
> + log_test "MLDv2 MRC non linear value 60000"
>
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_igmp_version 2
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_mld_version 1
> + bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_startup_query_count 2
> bridge vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 1000
> }
>
> --
> 2.43.0
>
^ permalink raw reply
* [PATCH] net/sched: sch_cake: fix NAT destination port not being updated in cake_update_flowkeys
From: Dudu Lu @ 2026-04-13 8:47 UTC (permalink / raw)
To: netdev; +Cc: toke, jhs, jiri, Dudu Lu
cake_update_flowkeys() is supposed to update the flow dissector keys
with the NAT-translated addresses and ports from conntrack, so that
CAKE's per-flow fairness correctly identifies post-NAT flows as
belonging to the same connection.
For the source port, this works correctly:
keys->ports.src = port; /* writes conntrack port into keys */
But for the destination port, the assignment is reversed:
port = keys->ports.dst; /* reads FROM keys into local var — no-op */
This means the NAT destination port is never updated in the flow keys.
As a result, when multiple connections are NATed to the same destination
(same IP + same port), CAKE treats them as separate flows because the
original (pre-NAT) destination ports differ. This completely defeats
CAKE's NAT-aware flow isolation when using the "nat" mode.
The vulnerability was introduced in commit b0c19ed6088a ("sch_cake: Take advantage
of skb->hash where appropriate") which refactored the original direct
assignment into a compare-and-conditionally-update pattern, but wrote
the destination port update backwards.
Fix by reversing the assignment direction to match the source port
pattern.
Fixes: b0c19ed6088a ("sch_cake: Take advantage of skb->hash where appropriate")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
---
net/sched/sch_cake.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 9efe23f8371b..4ac6c36ca6e4 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -619,7 +619,7 @@ static bool cake_update_flowkeys(struct flow_keys *keys,
}
port = rev ? tuple.src.u.all : tuple.dst.u.all;
if (port != keys->ports.dst) {
- port = keys->ports.dst;
+ keys->ports.dst = port;
upd = true;
}
}
--
2.39.3 (Apple Git-145)
^ permalink raw reply related
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