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>
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>
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
...
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>
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>
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'
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>
hfsc_qlen_notify() is not idempotent either and not friendly
to its callers, like fq_codel_dequeue(). Let's make it idempotent
to ease qdisc_tree_reduce_backlog() callers' life:
1. update_vf() decreases cl->cl_nactive, so we can check whether it is
non-zero before calling it.
2. eltree_remove() always removes RB node cl->el_node, but we can use
RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-4-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In the current implementation, skbprio enqueue/dequeue contains an assertion
that fails under certain conditions when SKBPRIO is used as a child qdisc under
TBF with specific parameters. The failure occurs because TBF sometimes peeks at
packets in the child qdisc without actually dequeuing them when tokens are
unavailable.
This peek operation creates a discrepancy between the parent and child qdisc
queue length counters. When TBF later receives a high-priority packet,
SKBPRIO's queue length may show a different value than what's reflected in its
internal priority queue tracking, triggering the assertion.
The fix removes this overly strict assertions in SKBPRIO, they are not
necessary at all.
Reported-by: syzbot+a3422a19b05ea96bee18@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a3422a19b05ea96bee18
Fixes: aea5f654e6 ("net/sched: add skbprio scheduler")
Cc: Nishanth Devarajan <ndev2021@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20250329222536.696204-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Continue Netlink conversions to per-namespace RTNL lock
(IPv4 routing, routing rules, routing next hops, ARP ioctls)
- Continue extending the use of netdev instance locks. As a driver
opt-in protect queue operations and (in due course) ethtool
operations with the instance lock and not RTNL lock.
- Support collecting TCP timestamps (data submitted, sent, acked) in
BPF, allowing for transparent (to the application) and lower
overhead tracking of TCP RPC performance.
- Tweak existing networking Rx zero-copy infra to support zero-copy
Rx via io_uring.
- Optimize MPTCP performance in single subflow mode by 29%.
- Enable GRO on packets which went thru XDP CPU redirect (were queued
for processing on a different CPU). Improving TCP stream
performance up to 2x.
- Improve performance of contended connect() by 200% by searching for
an available 4-tuple under RCU rather than a spin lock. Bring an
additional 229% improvement by tweaking hash distribution.
- Avoid unconditionally touching sk_tsflags on RX, improving
performance under UDP flood by as much as 10%.
- Avoid skb_clone() dance in ping_rcv() to improve performance under
ping flood.
- Avoid FIB lookup in netfilter if socket is available, 20% perf win.
- Rework network device creation (in-kernel) API to more clearly
identify network namespaces and their roles. There are up to 4
namespace roles but we used to have just 2 netns pointer arguments,
interpreted differently based on context.
- Use sysfs_break_active_protection() instead of trylock to avoid
deadlocks between unregistering objects and sysfs access.
- Add a new sysctl and sockopt for capping max retransmit timeout in
TCP.
- Support masking port and DSCP in routing rule matches.
- Support dumping IPv4 multicast addresses with RTM_GETMULTICAST.
- Support specifying at what time packet should be sent on AF_XDP
sockets.
- Expose TCP ULP diagnostic info (for TLS and MPTCP) to non-admin
users.
- Add Netlink YAML spec for WiFi (nl80211) and conntrack.
- Introduce EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL() for symbols
which only need to be exported when IPv6 support is built as a
module.
- Age FDB entries based on Rx not Tx traffic in VxLAN, similar to
normal bridging.
- Allow users to specify source port range for GENEVE tunnels.
- netconsole: allow attaching kernel release, CPU ID and task name to
messages as metadata
Driver API:
- Continue rework / fixing of Energy Efficient Ethernet (EEE) across
the SW layers. Delegate the responsibilities to phylink where
possible. Improve its handling in phylib.
- Support symmetric OR-XOR RSS hashing algorithm.
- Support tracking and preserving IRQ affinity by NAPI itself.
- Support loopback mode speed selection for interface selftests.
Device drivers:
- Remove the IBM LCS driver for s390
- Remove the sb1000 cable modem driver
- Add support for SFP module access over SMBus
- Add MCTP transport driver for MCTP-over-USB
- Enable XDP metadata support in multiple drivers
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- add PCIe TLP Processing Hints (TPH) support for new AMD
platforms
- support dumping RoCE queue state for debug
- opt into instance locking
- Intel (100G, ice, idpf):
- ice: rework MSI-X IRQ management and distribution
- ice: support for E830 devices
- iavf: add support for Rx timestamping
- iavf: opt into instance locking
- nVidia/Mellanox:
- mlx4: use page pool memory allocator for Rx
- mlx5: support for one PTP device per hardware clock
- mlx5: support for 200Gbps per-lane link modes
- mlx5: move IPSec policy check after decryption
- AMD/Solarflare:
- support FW flashing via devlink
- Cisco (enic):
- use page pool memory allocator for Rx
- enable 32, 64 byte CQEs
- get max rx/tx ring size from the device
- Meta (fbnic):
- support flow steering and RSS configuration
- report queue stats
- support TCP segmentation
- support IRQ coalescing
- support ring size configuration
- Marvell/Cavium:
- support AF_XDP
- Wangxun:
- support for PTP clock and timestamping
- Huawei (hibmcge):
- checksum offload
- add more statistics
- Ethernet virtual:
- VirtIO net:
- aggressively suppress Tx completions, improve perf by 96%
with 1 CPU and 55% with 2 CPUs
- expose NAPI to IRQ mapping and persist NAPI settings
- Google (gve):
- support XDP in DQO RDA Queue Format
- opt into instance locking
- Microsoft vNIC:
- support BIG TCP
- Ethernet NICs consumer, and embedded:
- Synopsys (stmmac):
- cleanup Tx and Tx clock setting and other link-focused
cleanups
- enable SGMII and 2500BASEX mode switching for Intel platforms
- support Sophgo SG2044
- Broadcom switches (b53):
- support for BCM53101
- TI:
- iep: add perout configuration support
- icssg: support XDP
- Cadence (macb):
- implement BQL
- Xilinx (axinet):
- support dynamic IRQ moderation and changing coalescing at
runtime
- implement BQL
- report standard stats
- MediaTek:
- support phylink managed EEE
- Intel:
- igc: don't restart the interface on every XDP program change
- RealTek (r8169):
- support reading registers of internal PHYs directly
- increase max jumbo packet size on RTL8125/RTL8126
- Airoha:
- support for RISC-V NPU packet processing unit
- enable scatter-gather and support MTU up to 9kB
- Tehuti (tn40xx):
- support cards with TN4010 MAC and an Aquantia AQR105 PHY
- Ethernet PHYs:
- support for TJA1102S, TJA1121
- dp83tg720: add randomized polling intervals for link detection
- dp83822: support changing the transmit amplitude voltage
- support for LEDs on 88q2xxx
- CAN:
- canxl: support Remote Request Substitution bit access
- flexcan: add S32G2/S32G3 SoC
- WiFi:
- remove cooked monitor support
- strict mode for better AP testing
- basic EPCS support
- OMI RX bandwidth reduction support
- batman-adv: add support for jumbo frames
- WiFi drivers:
- RealTek (rtw88):
- support RTL8814AE and RTL8814AU
- RealTek (rtw89):
- switch using wiphy_lock and wiphy_work
- add BB context to manipulate two PHY as preparation of MLO
- improve BT-coexistence mechanism to play A2DP smoothly
- Intel (iwlwifi):
- add new iwlmld sub-driver for latest HW/FW combinations
- MediaTek (mt76):
- preparation for mt7996 Multi-Link Operation (MLO) support
- Qualcomm/Atheros (ath12k):
- continued work on MLO
- Silabs (wfx):
- Wake-on-WLAN support
- Bluetooth:
- add support for skb TX SND/COMPLETION timestamping
- hci_core: enable buffer flow control for SCO/eSCO
- coredump: log devcd dumps into the monitor
- Bluetooth drivers:
- intel: add support to configure TX power
- nxp: handle bootloader error during cmd5 and cmd7"
* tag 'net-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1681 commits)
unix: fix up for "apparmor: add fine grained af_unix mediation"
mctp: Fix incorrect tx flow invalidation condition in mctp-i2c
net: usb: asix: ax88772: Increase phy_name size
net: phy: Introduce PHY_ID_SIZE — minimum size for PHY ID string
net: libwx: fix Tx L4 checksum
net: libwx: fix Tx descriptor content for some tunnel packets
atm: Fix NULL pointer dereference
net: tn40xx: add pci-id of the aqr105-based Tehuti TN4010 cards
net: tn40xx: prepare tn40xx driver to find phy of the TN9510 card
net: tn40xx: create swnode for mdio and aqr105 phy and add to mdiobus
net: phy: aquantia: add essential functions to aqr105 driver
net: phy: aquantia: search for firmware-name in fwnode
net: phy: aquantia: add probe function to aqr105 for firmware loading
net: phy: Add swnode support to mdiobus_scan
gve: add XDP DROP and PASS support for DQ
gve: update XDP allocation path support RX buffer posting
gve: merge packet buffer size fields
gve: update GQ RX to use buf_size
gve: introduce config-based allocation for XDP
gve: remove xdp_xsk_done and xdp_xsk_wakeup statistics
...
Pull timer cleanups from Thomas Gleixner:
"A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
the callback pointer. This turned out to be suboptimal for the
upcoming Rust integration and is obviously a silly implementation to
begin with.
This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
with hrtimer_setup(T, cb);
The conversion was done with Coccinelle and a few manual fixups.
Once the conversion has completely landed in mainline, hrtimer_init()
will be removed and the hrtimer::function becomes a private member"
* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
wifi: rt2x00: Switch to use hrtimer_update_function()
io_uring: Use helper function hrtimer_update_function()
serial: xilinx_uartps: Use helper function hrtimer_update_function()
ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
RDMA: Switch to use hrtimer_setup()
virtio: mem: Switch to use hrtimer_setup()
drm/vmwgfx: Switch to use hrtimer_setup()
drm/xe/oa: Switch to use hrtimer_setup()
drm/vkms: Switch to use hrtimer_setup()
drm/msm: Switch to use hrtimer_setup()
drm/i915/request: Switch to use hrtimer_setup()
drm/i915/uncore: Switch to use hrtimer_setup()
drm/i915/pmu: Switch to use hrtimer_setup()
drm/i915/perf: Switch to use hrtimer_setup()
drm/i915/gvt: Switch to use hrtimer_setup()
drm/i915/huc: Switch to use hrtimer_setup()
drm/amdgpu: Switch to use hrtimer_setup()
stm class: heartbeat: Switch to use hrtimer_setup()
i2c: Switch to use hrtimer_setup()
iio: Switch to use hrtimer_setup()
...
Cross-merge networking fixes after downstream PR (net-6.14-rc6).
Conflicts:
tools/testing/selftests/drivers/net/ping.py
75cc19c8ff ("selftests: drv-net: add xdp cases for ping.py")
de94e86974 ("selftests: drv-net: store addresses in dict indexed by ipver")
https://lore.kernel.org/netdev/20250311115758.17a1d414@canb.auug.org.au/
net/core/devmem.c
a70f891e0f ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()")
1d22d3060b ("net: drop rtnl_lock for queue_mgmt operations")
https://lore.kernel.org/netdev/20250313114929.43744df1@canb.auug.org.au/
Adjacent changes:
tools/testing/selftests/net/Makefile
6f50175cca ("selftests: Add IPv6 link-local address generation tests for GRE devices.")
2e5584e0f9 ("selftests/net: expand cmsg_ipv6.sh with ipv4")
drivers/net/ethernet/broadcom/bnxt/bnxt.c
661958552e ("eth: bnxt: do not use BNXT_VNIC_NTUPLE unconditionally in queue restart logic")
fe96d717d3 ("bnxt_en: Extend queue stop/start for TX rings")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The function qdisc_tree_reduce_backlog() uses TC_H_ROOT as a termination
condition when traversing up the qdisc tree to update parent backlog
counters. However, if a class is created with classid TC_H_ROOT, the
traversal terminates prematurely at this class instead of reaching the
actual root qdisc, causing parent statistics to be incorrectly maintained.
In case of DRR, this could lead to a crash as reported by Mingi Cho.
Prevent the creation of any Qdisc class with classid TC_H_ROOT
(0xFFFFFFFF) across all qdisc types, as suggested by Jamal.
Reported-by: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Fixes: 066a3b5b23 ("[NET_SCHED] sch_api: fix qdisc_tree_decrease_qlen() loop")
Link: https://patch.msgid.link/20250306232355.93864-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move the more esoteric helpers for netdev instance lock to
a dedicated header. This avoids growing netdevice.h to infinity
and makes rebuilding the kernel much faster (after touching
the header with the helpers).
The main netdev_lock() / netdev_unlock() functions are used
in static inlines in netdevice.h and will probably be used
most commonly, so keep them in netdevice.h.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If kzalloc in gred_init returns a NULL pointer, the code follows the
error handling path, invoking gred_destroy. This, in turn, calls
gred_offload, where memset could receive a NULL pointer as input,
potentially leading to a kernel crash.
When table->opt is NULL in gred_init(), gred_change_table_def()
is not called yet, so it is not necessary to call ->ndo_setup_tc()
in gred_offload().
Signed-off-by: Jun Yang <juny24602@gmail.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Fixes: f25c0515c5 ("net: sched: gred: dynamically allocate tc_gred_qopt_offload")
Link: https://patch.msgid.link/20250305154410.3505642-1-juny24602@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcf_exts_miss_cookie_base_alloc() calls xa_alloc_cyclic() which can
return 1 if the allocation succeeded after wrapping. This was treated as
an error, with value 1 returned to caller tcf_exts_init_ex() which sets
exts->actions to NULL and returns 1 to caller fl_change().
fl_change() treats err == 1 as success, calling tcf_exts_validate_ex()
which calls tcf_action_init() with exts->actions as argument, where it
is dereferenced.
Example trace:
BUG: kernel NULL pointer dereference, address: 0000000000000000
CPU: 114 PID: 16151 Comm: handler114 Kdump: loaded Not tainted 5.14.0-503.16.1.el9_5.x86_64 #1
RIP: 0010:tcf_action_init+0x1f8/0x2c0
Call Trace:
tcf_action_init+0x1f8/0x2c0
tcf_exts_validate_ex+0x175/0x190
fl_change+0x537/0x1120 [cls_flower]
Fixes: 80cd22c35c ("net/sched: cls_api: Support hardware miss to tc action")
Signed-off-by: Pierre Riteau <pierre@stackhpc.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/20250213223610.320278-1-pierre@stackhpc.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
qdisc_tree_reduce_backlog() notifies parent qdisc only if child
qdisc becomes empty, therefore we need to reduce the backlog of the
child qdisc before calling it. Otherwise it would miss the opportunity
to call cops->qlen_notify(), in the case of DRR, it resulted in UAF
since DRR uses ->qlen_notify() to maintain its active list.
Fixes: f8d4bc4550 ("net/sched: netem: account for backlog updates from child qdisc")
Cc: Martin Ottens <martin.ottens@fau.de>
Reported-by: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20250204005841.223511-4-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Expected behaviour:
In case we reach scheduler's limit, pfifo_tail_enqueue() will drop a
packet in scheduler's queue and decrease scheduler's qlen by one.
Then, pfifo_tail_enqueue() enqueue new packet and increase
scheduler's qlen by one. Finally, pfifo_tail_enqueue() return
`NET_XMIT_CN` status code.
Weird behaviour:
In case we set `sch->limit == 0` and trigger pfifo_tail_enqueue() on a
scheduler that has no packet, the 'drop a packet' step will do nothing.
This means the scheduler's qlen still has value equal 0.
Then, we continue to enqueue new packet and increase scheduler's qlen by
one. In summary, we can leverage pfifo_tail_enqueue() to increase qlen by
one and return `NET_XMIT_CN` status code.
The problem is:
Let's say we have two qdiscs: Qdisc_A and Qdisc_B.
- Qdisc_A's type must have '->graft()' function to create parent/child relationship.
Let's say Qdisc_A's type is `hfsc`. Enqueue packet to this qdisc will trigger `hfsc_enqueue`.
- Qdisc_B's type is pfifo_head_drop. Enqueue packet to this qdisc will trigger `pfifo_tail_enqueue`.
- Qdisc_B is configured to have `sch->limit == 0`.
- Qdisc_A is configured to route the enqueued's packet to Qdisc_B.
Enqueue packet through Qdisc_A will lead to:
- hfsc_enqueue(Qdisc_A) -> pfifo_tail_enqueue(Qdisc_B)
- Qdisc_B->q.qlen += 1
- pfifo_tail_enqueue() return `NET_XMIT_CN`
- hfsc_enqueue() check for `NET_XMIT_SUCCESS` and see `NET_XMIT_CN` => hfsc_enqueue() don't increase qlen of Qdisc_A.
The whole process lead to a situation where Qdisc_A->q.qlen == 0 and Qdisc_B->q.qlen == 1.
Replace 'hfsc' with other type (for example: 'drr') still lead to the same problem.
This violate the design where parent's qlen should equal to the sum of its childrens'qlen.
Bug impact: This issue can be used for user->kernel privilege escalation when it is reachable.
Fixes: 57dbb2d83d ("sched: add head drop fifo queue")
Reported-by: Quang Le <quanglex97@gmail.com>
Signed-off-by: Quang Le <quanglex97@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20250204005841.223511-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch addresses issues with filter counting in block (tcf_block),
particularly for software bypass scenarios, by introducing a more
accurate mechanism using useswcnt.
Previously, filtercnt and skipswcnt were introduced by:
Commit 2081fd3445 ("net: sched: cls_api: add filter counter") and
Commit f631ef39d8 ("net: sched: cls_api: add skip_sw counter")
filtercnt tracked all tp (tcf_proto) objects added to a block, and
skipswcnt counted tp objects with the skipsw attribute set.
The problem is: a single tp can contain multiple filters, some with skipsw
and others without. The current implementation fails in the case:
When the first filter in a tp has skipsw, both skipswcnt and filtercnt
are incremented, then adding a second filter without skipsw to the same
tp does not modify these counters because tp->counted is already set.
This results in bypass software behavior based solely on skipswcnt
equaling filtercnt, even when the block includes filters without
skipsw. Consequently, filters without skipsw are inadvertently bypassed.
To address this, the patch introduces useswcnt in block to explicitly count
tp objects containing at least one filter without skipsw. Key changes
include:
Whenever a filter without skipsw is added, its tp is marked with usesw
and counted in useswcnt. tc_run() now uses useswcnt to determine software
bypass, eliminating reliance on filtercnt and skipswcnt.
This refined approach prevents software bypass for blocks containing
mixed filters, ensuring correct behavior in tc_run().
Additionally, as atomic operations on useswcnt ensure thread safety and
tp->lock guards access to tp->usesw and tp->counted, the broader lock
down_write(&block->cb_lock) is no longer required in tc_new_tfilter(),
and this resolves a performance regression caused by the filter counting
mechanism during parallel filter insertions.
The improvement can be demonstrated using the following script:
# cat insert_tc_rules.sh
tc qdisc add dev ens1f0np0 ingress
for i in $(seq 16); do
taskset -c $i tc -b rules_$i.txt &
done
wait
Each of rules_$i.txt files above includes 100000 tc filter rules to a
mlx5 driver NIC ens1f0np0.
Without this patch:
# time sh insert_tc_rules.sh
real 0m50.780s
user 0m23.556s
sys 4m13.032s
With this patch:
# time sh insert_tc_rules.sh
real 0m17.718s
user 0m7.807s
sys 3m45.050s
Fixes: 047f340b36 ("net: sched: make skip_sw actually skip software")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Lion Ackermann was able to create a UAF which can be abused for privilege
escalation with the following script
Step 1. create root qdisc
tc qdisc add dev lo root handle 1:0 drr
step2. a class for packet aggregation do demonstrate uaf
tc class add dev lo classid 1:1 drr
step3. a class for nesting
tc class add dev lo classid 1:2 drr
step4. a class to graft qdisc to
tc class add dev lo classid 1:3 drr
step5.
tc qdisc add dev lo parent 1:1 handle 2:0 plug limit 1024
step6.
tc qdisc add dev lo parent 1:2 handle 3:0 drr
step7.
tc class add dev lo classid 3:1 drr
step 8.
tc qdisc add dev lo parent 3:1 handle 4:0 pfifo
step 9. Display the class/qdisc layout
tc class ls dev lo
class drr 1:1 root leaf 2: quantum 64Kb
class drr 1:2 root leaf 3: quantum 64Kb
class drr 3:1 root leaf 4: quantum 64Kb
tc qdisc ls
qdisc drr 1: dev lo root refcnt 2
qdisc plug 2: dev lo parent 1:1
qdisc pfifo 4: dev lo parent 3:1 limit 1000p
qdisc drr 3: dev lo parent 1:2
step10. trigger the bug <=== prevented by this patch
tc qdisc replace dev lo parent 1:3 handle 4:0
step 11. Redisplay again the qdiscs/classes
tc class ls dev lo
class drr 1:1 root leaf 2: quantum 64Kb
class drr 1:2 root leaf 3: quantum 64Kb
class drr 1:3 root leaf 4: quantum 64Kb
class drr 3:1 root leaf 4: quantum 64Kb
tc qdisc ls
qdisc drr 1: dev lo root refcnt 2
qdisc plug 2: dev lo parent 1:1
qdisc pfifo 4: dev lo parent 3:1 refcnt 2 limit 1000p
qdisc drr 3: dev lo parent 1:2
Observe that a) parent for 4:0 does not change despite the replace request.
There can only be one parent. b) refcount has gone up by two for 4:0 and
c) both class 1:3 and 3:1 are pointing to it.
Step 12. send one packet to plug
echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10001))
step13. send one packet to the grafted fifo
echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10003))
step14. lets trigger the uaf
tc class delete dev lo classid 1:3
tc class delete dev lo classid 1:1
The semantics of "replace" is for a del/add _on the same node_ and not
a delete from one node(3:1) and add to another node (1:3) as in step10.
While we could "fix" with a more complex approach there could be
consequences to expectations so the patch takes the preventive approach of
"disallow such config".
Joint work with Lion Ackermann <nnamrec@gmail.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250116013713.900000-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The existing error message ("Invalid qdisc name") is confusing
because it suggests that there is no qdisc with the given name. In
fact, the name does refer to a valid qdisc, but it doesn't match
the kind of an existing qdisc being modified or replaced. The
new error message provides more detail to eliminate confusion.
Signed-off-by: John Ousterhout <ouster@cs.stanford.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250116195642.2794-1-ouster@cs.stanford.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dev_deactivate_many() role is to remove the qdiscs
of a network device.
When/if a qdisc is dismantled, an rcu grace period
is needed to make sure all outstanding qdisc enqueue
are done before we proceed with a qdisc reset.
Most virtual devices do not have a qdisc.
We can call the expensive synchronize_net() only
if needed.
Note that dev_deactivate_many() does not have to deal
with qdisc-less dev_queue_xmit, as an old comment
was claiming.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250109171850.2871194-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Even though we fixed a logic error in the commit cited below, syzbot
still managed to trigger an underflow of the per-host bulk flow
counters, leading to an out of bounds memory access.
To avoid any such logic errors causing out of bounds memory accesses,
this commit factors out all accesses to the per-host bulk flow counters
to a series of helpers that perform bounds-checking before any
increments and decrements. This also has the benefit of improving
readability by moving the conditional checks for the flow mode into
these helpers, instead of having them spread out throughout the
code (which was the cause of the original logic error).
As part of this change, the flow quantum calculation is consolidated
into a helper function, which means that the dithering applied to the
ost load scaling is now applied both in the DRR rotation and when a
sparse flow's quantum is first initiated. The only user-visible effect
of this is that the maximum packet size that can be sent while a flow
stays sparse will now vary with +/- one byte in some cases. This should
not make a noticeable difference in practice, and thus it's not worth
complicating the code to preserve the old behaviour.
Fixes: 546ea84d07 ("sched: sch_cake: fix bulk flow accounting logic for host fairness")
Reported-by: syzbot+f63600d288bfb7057424@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Link: https://patch.msgid.link/20250107120105.70685-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In commit d7811e623d ("[NET]: Drop tx lock in dev_watchdog_up")
dev_watchdog_up() became a simple wrapper for __netdev_watchdog_up()
Herbert also said : "In 2.6.19 we can eliminate the unnecessary
__dev_watchdog_up and replace it with dev_watchdog_up."
This patch consolidates things to have only two functions, with
a common prefix.
- netdev_watchdog_up(), exported for the sake of one freescale driver.
This replaces __netdev_watchdog_up() and dev_watchdog_up().
- netdev_watchdog_down(), static to net/sched/sch_generic.c
This replaces dev_watchdog_down().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20250105090924.1661822-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
