Blamed commit moved the TIME_WAIT-derived ISN from the skb control
block to a per-CPU variable, assuming the value would always be consumed
by tcp_conn_request() for the same packet that wrote it. That assumption
is violated by multiple drop paths between the producer
(__this_cpu_write(tcp_tw_isn, isn) in tcp_v{4,6}_rcv()) and the consumer
(tcp_conn_request()):
- min_ttl / min_hopcount check
- xfrm policy check
- tcp_inbound_hash() MD5/AO mismatch
- tcp_filter() eBPF/SO_ATTACH_FILTER drop
- th->syn && th->fin discard in tcp_rcv_state_process() TCP_LISTEN
- psp_sk_rx_policy_check() in tcp_v{4,6}_do_rcv()
- tcp_checksum_complete() in tcp_v{4,6}_do_rcv()
- tcp_v{4,6}_cookie_check() returning NULL
When a packet is dropped on any of these paths, tcp_tw_isn is left set.
The next SYN processed on the same CPU then consumes the non zero value in
tcp_conn_request(), receiving a potentially predictable ISN.
This patch moves back tcp_tw_isn to skb->cb[], getting rid of the per-cpu
variable.
Note that tcp_v{4,6}_fill_cb() do not set it.
Very litle impact on overall code size/complexity:
$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/0 grow/shrink: 2/1 up/down: 8/-15 (-7)
Function old new delta
tcp_v6_rcv 3038 3042 +4
tcp_v4_rcv 3035 3039 +4
tcp_conn_request 2938 2923 -15
Total: Before=24436060, After=24436053, chg -0.00%
Fixes: 41eecbd712b7 ("tcp: replace TCP_SKB_CB(skb)->tcp_tw_isn with a per-cpu field")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260519084611.2485277-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp_child_process( .. child ...) currently calls sock_put(child).
Unfortunately @child (named @nsk in callers) can be used after
this point to send a RST packet.
To fix this UAF, I remove the sock_put() from tcp_child_process()
and let the callers handle this after it is safe.
Remove @rsk variable in tcp_v4_do_rcv() and change tcp_v6_do_rcv()
so that both functions look the same.
Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.")
Reported-by: Damiano Melotti <melotti@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260505153927.3435532-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Support HW queue leasing, allowing containers to be granted access
to HW queues for zero-copy operations and AF_XDP
- Number of code moves to help the compiler with inlining. Avoid
output arguments for returning drop reason where possible
- Rework drop handling within qdiscs to include more metadata about
the reason and dropping qdisc in the tracepoints
- Remove the rtnl_lock use from IP Multicast Routing
- Pack size information into the Rx Flow Steering table pointer
itself. This allows making the table itself a flat array of u32s,
thus making the table allocation size a power of two
- Report TCP delayed ack timer information via socket diag
- Add ip_local_port_step_width sysctl to allow distributing the
randomly selected ports more evenly throughout the allowed space
- Add support for per-route tunsrc in IPv6 segment routing
- Start work of switching sockopt handling to iov_iter
- Improve dynamic recvbuf sizing in MPTCP, limit burstiness and avoid
buffer size drifting up
- Support MSG_EOR in MPTCP
- Add stp_mode attribute to the bridge driver for STP mode selection.
This addresses concerns about call_usermodehelper() usage
- Remove UDP-Lite support (as announced in 2023)
- Remove support for building IPv6 as a module. Remove the now
unnecessary function calling indirection
Cross-tree stuff:
- Move Michael MIC code from generic crypto into wireless, it's
considered insecure but some WiFi networks still need it
Netfilter:
- Switch nft_fib_ipv6 module to no longer need temporary dst_entry
object allocations by using fib6_lookup() + RCU.
Florian W reports this gets us ~13% higher packet rate
- Convert IPVS's global __ip_vs_mutex to per-net service_mutex and
switch the service tables to be per-net. Convert some code that
walks the service lists to use RCU instead of the service_mutex
- Add more opinionated input validation to lower security exposure
- Make IPVS hash tables to be per-netns and resizable
Wireless:
- Finished assoc frame encryption/EPPKE/802.1X-over-auth
- Radar detection improvements
- Add 6 GHz incumbent signal detection APIs
- Multi-link support for FILS, probe response templates and client
probing
- New APIs and mac80211 support for NAN (Neighbor Aware Networking,
aka Wi-Fi Aware) so less work must be in firmware
Driver API:
- Add numerical ID for devlink instances (to avoid having to create
fake bus/device pairs just to have an ID). Support shared devlink
instances which span multiple PFs
- Add standard counters for reporting pause storm events (implement
in mlx5 and fbnic)
- Add configuration API for completion writeback buffering (implement
in mana)
- Support driver-initiated change of RSS context sizes
- Support DPLL monitoring input frequency (implement in zl3073x)
- Support per-port resources in devlink (implement in mlx5)
Misc:
- Expand the YAML spec for Netfilter
Drivers
- Software:
- macvlan: support multicast rx for bridge ports with shared
source MAC address
- team: decouple receive and transmit enablement for IEEE 802.3ad
LACP "independent control"
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- support high order pages in zero-copy mode (for payload
coalescing)
- support multiple packets in a page (for systems with 64kB
pages)
- Broadcom 25-400GE (bnxt):
- implement XDP RSS hash metadata extraction
- add software fallback for UDP GSO, lowering the IOMMU cost
- Broadcom 800GE (bnge):
- add link status and configuration handling
- add various HW and SW statistics
- Marvell/Cavium:
- NPC HW block support for cn20k
- Huawei (hinic3):
- add mailbox / control queue
- add rx VLAN offload
- add driver info and link management
- Ethernet NICs:
- Marvell/Aquantia:
- support reading SFP module info on some AQC100 cards
- Realtek PCI (r8169):
- add support for RTL8125cp
- Realtek USB (r8152):
- support for the RTL8157 5Gbit chip
- add 2500baseT EEE status/configuration support
- Ethernet NICs embedded and off-the-shelf IP:
- Synopsys (stmmac):
- cleanup and reorganize SerDes handling and PCS support
- cleanup descriptor handling and per-platform data
- cleanup and consolidate MDIO defines and handling
- shrink driver memory use for internal structures
- improve Tx IRQ coalescing
- improve TCP segmentation handling
- add support for Spacemit K3
- Cadence (macb):
- support PHYs that have inband autoneg disabled with GEM
- support IEEE 802.3az EEE
- rework usrio capabilities and handling
- AMD (xgbe):
- improve power management for S0i3
- improve TX resilience for link-down handling
- Virtual:
- Google cloud vNIC:
- support larger ring sizes in DQO-QPL mode
- improve HW-GRO handling
- support UDP GSO for DQO format
- PCIe NTB:
- support queue count configuration
- Ethernet PHYs:
- automatically disable PHY autonomous EEE if MAC is in charge
- Broadcom:
- add BCM84891/BCM84892 support
- Micrel:
- support for LAN9645X internal PHY
- Realtek:
- add RTL8224 pair order support
- support PHY LEDs on RTL8211F-VD
- support spread spectrum clocking (SSC)
- Maxlinear:
- add PHY-level statistics via ethtool
- Ethernet switches:
- Maxlinear (mxl862xx):
- support for bridge offloading
- support for VLANs
- support driver statistics
- Bluetooth:
- large number of fixes and new device IDs
- Mediatek:
- support MT6639 (MT7927)
- support MT7902 SDIO
- WiFi:
- Intel (iwlwifi):
- UNII-9 and continuing UHR work
- MediaTek (mt76):
- mt7996/mt7925 MLO fixes/improvements
- mt7996 NPU support (HW eth/wifi traffic offload)
- Qualcomm (ath12k):
- monitor mode support on IPQ5332
- basic hwmon temperature reporting
- support IPQ5424
- Realtek:
- add USB RX aggregation to improve performance
- add USB TX flow control by tracking in-flight URBs
- Cellular:
- IPA v5.2 support"
* tag 'net-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1561 commits)
net: pse-pd: fix kernel-doc function name for pse_control_find_by_id()
wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit
wireguard: allowedips: remove redundant space
tools: ynl: add sample for wireguard
wireguard: allowedips: Use kfree_rcu() instead of call_rcu()
MAINTAINERS: Add netkit selftest files
selftests/net: Add additional test coverage in nk_qlease
selftests/net: Split netdevsim tests from HW tests in nk_qlease
tools/ynl: Make YnlFamily closeable as a context manager
net: airoha: Add missing PPE configurations in airoha_ppe_hw_init()
net: airoha: Fix VIP configuration for AN7583 SoC
net: caif: clear client service pointer on teardown
net: strparser: fix skb_head leak in strp_abort_strp()
net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()
selftests/bpf: add test for xdp_master_redirect with bond not up
net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master
net: airoha: Remove PCE_MC_EN_MASK bit in REG_FE_PCE_CFG configuration
sctp: disable BH before calling udp_tunnel_xmit_skb()
sctp: fix missing encap_port propagation for GSO fragments
net: airoha: Rely on net_device pointer in ETS callbacks
...
Pull vfs i_ino updates from Christian Brauner: "For historical reasons, the inode->i_ino field is an unsigned long, which means that it's 32 bits on 32 bit architectures. This has caused a number of filesystems to implement hacks to hash a 64-bit identifier into a 32-bit field, and deprives us of a universal identifier field for an inode. This changes the inode->i_ino field from an unsigned long to a u64. This shouldn't make any material difference on 64-bit hosts, but 32-bit hosts will see struct inode grow by at least 4 bytes. This could have effects on slabcache sizes and field alignment. The bulk of the changes are to format strings and tracepoints, since the kernel itself doesn't care that much about the i_ino field. The first patch changes some vfs function arguments, so check that one out carefully. With this change, we may be able to shrink some inode structures. For instance, struct nfs_inode has a fileid field that holds the 64-bit inode number. With this set of changes, that field could be eliminated. I'd rather leave that sort of cleanups for later just to keep this simple" * tag 'vfs-7.1-rc1.kino' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nilfs2: fix 64-bit division operations in nilfs_bmap_find_target_in_group() EVM: add comment describing why ino field is still unsigned long vfs: remove externs from fs.h on functions modified by i_ino widening treewide: fix missed i_ino format specifier conversions ext4: fix signed format specifier in ext4_load_inode trace event treewide: change inode->i_ino from unsigned long to u64 nilfs2: widen trace event i_ino fields to u64 f2fs: widen trace event i_ino fields to u64 ext4: widen trace event i_ino fields to u64 zonefs: widen trace event i_ino fields to u64 hugetlbfs: widen trace event i_ino fields to u64 ext2: widen trace event i_ino fields to u64 cachefiles: widen trace event i_ino fields to u64 vfs: widen trace event i_ino fields to u64 net: change sock.sk_ino and sock_i_ino() to u64 audit: widen ino fields to u64 vfs: widen inode hash/lookup functions to u64
Eric Dumazet says: ==================== net: reduce sk_filter() (and friends) bloat Some functions return an error by value, and a drop_reason by an output parameter. This extra parameter can force stack canaries. A drop_reason is enough and more efficient. This series reduces bloat by 678 bytes on x86_64: $ scripts/bloat-o-meter -t vmlinux.old vmlinux.final add/remove: 0/0 grow/shrink: 3/18 up/down: 79/-757 (-678) Function old new delta vsock_queue_rcv_skb 50 79 +29 ipmr_cache_report 1290 1315 +25 ip6mr_cache_report 1322 1347 +25 tcp_v6_rcv 3169 3167 -2 packet_rcv_spkt 329 327 -2 unix_dgram_sendmsg 1731 1726 -5 netlink_unicast 957 945 -12 netlink_dump 1372 1359 -13 sk_filter_trim_cap 889 858 -31 netlink_broadcast_filtered 1633 1595 -38 tcp_v4_rcv 3152 3111 -41 raw_rcv_skb 122 80 -42 ping_queue_rcv_skb 109 61 -48 ping_rcv 215 162 -53 rawv6_rcv_skb 278 224 -54 __sk_receive_skb 690 632 -58 raw_rcv 591 527 -64 udpv6_queue_rcv_one_skb 935 869 -66 udp_queue_rcv_one_skb 919 853 -66 tun_net_xmit 1146 1074 -72 sock_queue_rcv_skb_reason 166 76 -90 Total: Before=29722890, After=29722212, chg -0.00% Future conversions from sock_queue_rcv_skb() to sock_queue_rcv_skb_reason() can be done later. ==================== Link: https://patch.msgid.link/20260409145625.2306224-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sk_filter_trim_cap() will soon return the reason by value, do the same for tcp_filter(). Note: tcp_filter() is no longer inlined. Following patch will inline it again. $ scripts/bloat-o-meter -t vmlinux.4 vmlinux.5 add/remove: 2/0 grow/shrink: 0/2 up/down: 186/-43 (143) Function old new delta tcp_filter - 154 +154 __pfx_tcp_filter - 32 +32 tcp_v4_rcv 3152 3143 -9 tcp_v6_rcv 3169 3135 -34 Total: Before=29722640, After=29722783, chg +0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260409145625.2306224-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Small improvement in SYN processing, to directly call tcp_v6_init_seq_and_ts_off() or tcp_v4_init_seq_and_ts_off(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260410174950.745670-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Part of a stack canary removal from tcp_v{4,6}_rcv().
Return a drop_reason instead of a boolean, so that we no longer
have to pass the address of a local variable.
$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-37 (-37)
Function old new delta
tcp_v6_rcv 3133 3129 -4
tcp_v4_rcv 3206 3202 -4
tcp_add_backlog 1281 1252 -29
Total: Before=25567186, After=25567149, chg -0.00%
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260409101147.1642967-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As IPv6 is built-in only, the macro is always evaluating to an empty one. Remove it completely from the code. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260325120928.15848-3-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If incoming skb dst matches the socket cached one,
there is no need to call again dst->ops->check().
Network layer already validated the skb dst for us,
usually from tcp_v{4,6}_early_demux().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260306154322.1086539-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>