BMC/Intel-BMC/linux.git/net/core/dev.c, branch dev-5.14-intel

napi: fix race inside napi_enable

2021-09-30T08:12:58+00:00

[ Upstream commit 3765996e4f0b8a755cab215a08df744490c76052 ] The process will cause napi.state to contain NAPI_STATE_SCHED and not in the poll_list, which will cause napi_disable() to get stuck. The prefix "NAPI_STATE_" is removed in the figure below, and NAPI_STATE_HASHED is ignored in napi.state. CPU0 | CPU1 | napi.state =============================================================================== napi_disable() | | SCHED | NPSVC napi_enable() | | { | | smp_mb__before_atomic(); | | clear_bit(SCHED, &n->state); | | NPSVC | napi_schedule_prep() | SCHED | NPSVC | napi_poll() | | napi_complete_done() | | { | | if (n->state & (NPSVC | | (1) | _BUSY_POLL))) | | return false; | | ................ | | } | SCHED | NPSVC | | clear_bit(NPSVC, &n->state); | | SCHED } | | | | napi_schedule_prep() | | SCHED | MISSED (2) (1) Here return direct. Because of NAPI_STATE_NPSVC exists. (2) NAPI_STATE_SCHED exists. So not add napi.poll_list to sd->poll_list Since NAPI_STATE_SCHED already exists and napi is not in the sd->poll_list queue, NAPI_STATE_SCHED cannot be cleared and will always exist. 1. This will cause this queue to no longer receive packets. 2. If you encounter napi_disable under the protection of rtnl_lock, it will cause the entire rtnl_lock to be locked, affecting the overall system. This patch uses cmpxchg to implement napi_enable(), which ensures that there will be no race due to the separation of clear two bits. Fixes: 2d8bff12699abc ("netpoll: Close race condition between poll_one_napi and napi_disable") Signed-off-by: Xuan Zhuo Reviewed-by: Dust Li Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2021-07-15T21:39:45+00:00

Andrii Nakryiko says: ==================== pull-request: bpf 2021-07-15 The following pull-request contains BPF updates for your *net* tree. We've added 9 non-merge commits during the last 5 day(s) which contain a total of 9 files changed, 37 insertions(+), 15 deletions(-). The main changes are: 1) Fix NULL pointer dereference in BPF_TEST_RUN for BPF_XDP_DEVMAP and BPF_XDP_CPUMAP programs, from Xuan Zhuo. 2) Fix use-after-free of net_device in XDP bpf_link, from Xuan Zhuo. 3) Follow-up fix to subprog poke descriptor use-after-free problem, from Daniel Borkmann and John Fastabend. 4) Fix out-of-range array access in s390 BPF JIT backend, from Colin Ian King. 5) Fix memory leak in BPF sockmap, from John Fastabend. 6) Fix for sockmap to prevent proc stats reporting bug, from John Fastabend and Jakub Sitnicki. 7) Fix NULL pointer dereference in bpftool, from Tobias Klauser. 8) AF_XDP documentation fixes, from Baruch Siach. ==================== Signed-off-by: David S. Miller

net_sched: introduce tracepoint trace_qdisc_enqueue()

2021-07-15T17:32:38+00:00

Tracepoint trace_qdisc_enqueue() is introduced to trace skb at the entrance of TC layer on TX side. This is similar to trace_qdisc_dequeue(): 1. For both we only trace successful cases. The failure cases can be traced via trace_kfree_skb(). 2. They are called at entrance or exit of TC layer, not for each ->enqueue() or ->dequeue(). This is intentional, because we want to make trace_qdisc_enqueue() symmetric to trace_qdisc_dequeue(), which is easier to use. The return value of qdisc_enqueue() is not interesting here, we have Qdisc's drop packets in ->dequeue(), it is impossible to trace them even if we have the return value, the only way to trace them is tracing kfree_skb(). We only add information we need to trace ring buffer. If any other information is needed, it is easy to extend it without breaking ABI, see commit 3dd344ea84e1 ("net: tracepoint: exposing sk_family in all tcp:tracepoints"). Reviewed-by: Cong Wang Signed-off-by: Qitao Xu Signed-off-by: David S. Miller

xdp, net: Fix use-after-free in bpf_xdp_link_release

2021-07-13T15:22:31+00:00

The problem occurs between dev_get_by_index() and dev_xdp_attach_link(). At this point, dev_xdp_uninstall() is called. Then xdp link will not be detached automatically when dev is released. But link->dev already points to dev, when xdp link is released, dev will still be accessed, but dev has been released. dev_get_by_index() | link->dev = dev | | rtnl_lock() | unregister_netdevice_many() | dev_xdp_uninstall() | rtnl_unlock() rtnl_lock(); | dev_xdp_attach_link() | rtnl_unlock(); | | netdev_run_todo() // dev released bpf_xdp_link_release() | /* access dev. | use-after-free */ | [ 45.966867] BUG: KASAN: use-after-free in bpf_xdp_link_release+0x3b8/0x3d0 [ 45.967619] Read of size 8 at addr ffff00000f9980c8 by task a.out/732 [ 45.968297] [ 45.968502] CPU: 1 PID: 732 Comm: a.out Not tainted 5.13.0+ #22 [ 45.969222] Hardware name: linux,dummy-virt (DT) [ 45.969795] Call trace: [ 45.970106] dump_backtrace+0x0/0x4c8 [ 45.970564] show_stack+0x30/0x40 [ 45.970981] dump_stack_lvl+0x120/0x18c [ 45.971470] print_address_description.constprop.0+0x74/0x30c [ 45.972182] kasan_report+0x1e8/0x200 [ 45.972659] __asan_report_load8_noabort+0x2c/0x50 [ 45.973273] bpf_xdp_link_release+0x3b8/0x3d0 [ 45.973834] bpf_link_free+0xd0/0x188 [ 45.974315] bpf_link_put+0x1d0/0x218 [ 45.974790] bpf_link_release+0x3c/0x58 [ 45.975291] __fput+0x20c/0x7e8 [ 45.975706] ____fput+0x24/0x30 [ 45.976117] task_work_run+0x104/0x258 [ 45.976609] do_notify_resume+0x894/0xaf8 [ 45.977121] work_pending+0xc/0x328 [ 45.977575] [ 45.977775] The buggy address belongs to the page: [ 45.978369] page:fffffc00003e6600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4f998 [ 45.979522] flags: 0x7fffe0000000000(node=0|zone=0|lastcpupid=0x3ffff) [ 45.980349] raw: 07fffe0000000000 fffffc00003e6708 ffff0000dac3c010 0000000000000000 [ 45.981309] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 45.982259] page dumped because: kasan: bad access detected [ 45.982948] [ 45.983153] Memory state around the buggy address: [ 45.983753] ffff00000f997f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 45.984645] ffff00000f998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.985533] >ffff00000f998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.986419] ^ [ 45.987112] ffff00000f998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.988006] ffff00000f998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.988895] ================================================================== [ 45.989773] Disabling lock debugging due to kernel taint [ 45.990552] Kernel panic - not syncing: panic_on_warn set ... [ 45.991166] CPU: 1 PID: 732 Comm: a.out Tainted: G B 5.13.0+ #22 [ 45.991929] Hardware name: linux,dummy-virt (DT) [ 45.992448] Call trace: [ 45.992753] dump_backtrace+0x0/0x4c8 [ 45.993208] show_stack+0x30/0x40 [ 45.993627] dump_stack_lvl+0x120/0x18c [ 45.994113] dump_stack+0x1c/0x34 [ 45.994530] panic+0x3a4/0x7d8 [ 45.994930] end_report+0x194/0x198 [ 45.995380] kasan_report+0x134/0x200 [ 45.995850] __asan_report_load8_noabort+0x2c/0x50 [ 45.996453] bpf_xdp_link_release+0x3b8/0x3d0 [ 45.997007] bpf_link_free+0xd0/0x188 [ 45.997474] bpf_link_put+0x1d0/0x218 [ 45.997942] bpf_link_release+0x3c/0x58 [ 45.998429] __fput+0x20c/0x7e8 [ 45.998833] ____fput+0x24/0x30 [ 45.999247] task_work_run+0x104/0x258 [ 45.999731] do_notify_resume+0x894/0xaf8 [ 46.000236] work_pending+0xc/0x328 [ 46.000697] SMP: stopping secondary CPUs [ 46.001226] Dumping ftrace buffer: [ 46.001663] (ftrace buffer empty) [ 46.002110] Kernel Offset: disabled [ 46.002545] CPU features: 0x00000001,23202c00 [ 46.003080] Memory Limit: none Fixes: aa8d3a716b59db6c ("bpf, xdp: Add bpf_link-based XDP attachment API") Reported-by: Abaci Signed-off-by: Xuan Zhuo Signed-off-by: Alexei Starovoitov Reviewed-by: Dust Li Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210710031635.41649-1-xuanzhuo@linux.alibaba.com

net: do not reuse skbuff allocated from skbuff_fclone_cache in the skb cache

2021-07-09T18:26:27+00:00

Some socket buffers allocated in the fclone cache (in __alloc_skb) can end-up in the following path[1]: napi_skb_finish __kfree_skb_defer napi_skb_cache_put The issue is napi_skb_cache_put is not fclone friendly and will put those skbuff in the skb cache to be reused later, although this cache only expects skbuff allocated from skbuff_head_cache. When this happens the skbuff is eventually freed using the wrong origin cache, and we can see traces similar to: [ 1223.947534] cache_from_obj: Wrong slab cache. skbuff_head_cache but object is from skbuff_fclone_cache [ 1223.948895] WARNING: CPU: 3 PID: 0 at mm/slab.h:442 kmem_cache_free+0x251/0x3e0 [ 1223.950211] Modules linked in: [ 1223.950680] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.13.0+ #474 [ 1223.951587] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-3.fc34 04/01/2014 [ 1223.953060] RIP: 0010:kmem_cache_free+0x251/0x3e0 Leading sometimes to other memory related issues. Fix this by using __kfree_skb for fclone skbuff, similar to what is done the other place __kfree_skb_defer is called. [1] At least in setups using veth pairs and tunnels. Building a kernel with KASAN we can for example see packets allocated in sk_stream_alloc_skb hit the above path and later the issue arises when the skbuff is reused. Fixes: 9243adfc311a ("skbuff: queue NAPI_MERGED_FREE skbs into NAPI cache instead of freeing") Cc: Alexander Lobakin Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller

skbuff: Fix build with SKB extensions disabled

2021-07-08T07:07:14+00:00

We will fail to build with CONFIG_SKB_EXTENSIONS disabled after 8550ff8d8c75 ("skbuff: Release nfct refcount on napi stolen or re-used skbs") since there is an unconditionally use of skb_ext_find() without an appropriate stub. Simply build the code conditionally and properly guard against both COFNIG_SKB_EXTENSIONS as well as CONFIG_NET_TC_SKB_EXT being disabled. Fixes: Fixes: 8550ff8d8c75 ("skbuff: Release nfct refcount on napi stolen or re-used skbs") Signed-off-by: Florian Fainelli Reviewed-by: Roi Dayan Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

skbuff: Release nfct refcount on napi stolen or re-used skbs

2021-07-06T17:26:29+00:00

When multiple SKBs are merged to a new skb under napi GRO, or SKB is re-used by napi, if nfct was set for them in the driver, it will not be released while freeing their stolen head state or on re-use. Release nfct on napi's stolen or re-used SKBs, and in gro_list_prepare, check conntrack metadata diff. Fixes: 5c6b94604744 ("net/mlx5e: CT: Handle misses after executing CT action") Reviewed-by: Roi Dayan Signed-off-by: Paul Blakey Signed-off-by: David S. Miller

Merge tag 'net-next-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2021-06-30T22:51:09+00:00

Pull networking updates from Jakub Kicinski: "Core: - BPF: - add syscall program type and libbpf support for generating instructions and bindings for in-kernel BPF loaders (BPF loaders for BPF), this is a stepping stone for signed BPF programs - infrastructure to migrate TCP child sockets from one listener to another in the same reuseport group/map to improve flexibility of service hand-off/restart - add broadcast support to XDP redirect - allow bypass of the lockless qdisc to improving performance (for pktgen: +23% with one thread, +44% with 2 threads) - add a simpler version of "DO_ONCE()" which does not require jump labels, intended for slow-path usage - virtio/vsock: introduce SOCK_SEQPACKET support - add getsocketopt to retrieve netns cookie - ip: treat lowest address of a IPv4 subnet as ordinary unicast address allowing reclaiming of precious IPv4 addresses - ipv6: use prandom_u32() for ID generation - ip: add support for more flexible field selection for hashing across multi-path routes (w/ offload to mlxsw) - icmp: add support for extended RFC 8335 PROBE (ping) - seg6: add support for SRv6 End.DT46 behavior - mptcp: - DSS checksum support (RFC 8684) to detect middlebox meddling - support Connection-time 'C' flag - time stamping support - sctp: packetization Layer Path MTU Discovery (RFC 8899) - xfrm: speed up state addition with seq set - WiFi: - hidden AP discovery on 6 GHz and other HE 6 GHz improvements - aggregation handling improvements for some drivers - minstrel improvements for no-ack frames - deferred rate control for TXQs to improve reaction times - switch from round robin to virtual time-based airtime scheduler - add trace points: - tcp checksum errors - openvswitch - action execution, upcalls - socket errors via sk_error_report Device APIs: - devlink: add rate API for hierarchical control of max egress rate of virtual devices (VFs, SFs etc.) - don't require RCU read lock to be held around BPF hooks in NAPI context - page_pool: generic buffer recycling New hardware/drivers: - mobile: - iosm: PCIe Driver for Intel M.2 Modem - support for Qualcomm MSM8998 (ipa) - WiFi: Qualcomm QCN9074 and WCN6855 PCI devices - sparx5: Microchip SparX-5 family of Enterprise Ethernet switches - Mellanox BlueField Gigabit Ethernet (control NIC of the DPU) - NXP SJA1110 Automotive Ethernet 10-port switch - Qualcomm QCA8327 switch support (qca8k) - Mikrotik 10/25G NIC (atl1c) Driver changes: - ACPI support for some MDIO, MAC and PHY devices from Marvell and NXP (our first foray into MAC/PHY description via ACPI) - HW timestamping (PTP) support: bnxt_en, ice, sja1105, hns3, tja11xx - Mellanox/Nvidia NIC (mlx5) - NIC VF offload of L2 bridging - support IRQ distribution to Sub-functions - Marvell (prestera): - add flower and match all - devlink trap - link aggregation - Netronome (nfp): connection tracking offload - Intel 1GE (igc): add AF_XDP support - Marvell DPU (octeontx2): ingress ratelimit offload - Google vNIC (gve): new ring/descriptor format support - Qualcomm mobile (rmnet & ipa): inline checksum offload support - MediaTek WiFi (mt76) - mt7915 MSI support - mt7915 Tx status reporting - mt7915 thermal sensors support - mt7921 decapsulation offload - mt7921 enable runtime pm and deep sleep - Realtek WiFi (rtw88) - beacon filter support - Tx antenna path diversity support - firmware crash information via devcoredump - Qualcomm WiFi (wcn36xx) - Wake-on-WLAN support with magic packets and GTK rekeying - Micrel PHY (ksz886x/ksz8081): add cable test support" * tag 'net-next-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2168 commits) tcp: change ICSK_CA_PRIV_SIZE definition tcp_yeah: check struct yeah size at compile time gve: DQO: Fix off by one in gve_rx_dqo() stmmac: intel: set PCI_D3hot in suspend stmmac: intel: Enable PHY WOL option in EHL net: stmmac: option to enable PHY WOL with PMT enabled net: say "local" instead of "static" addresses in ndo_dflt_fdb_{add,del} net: use netdev_info in ndo_dflt_fdb_{add,del} ptp: Set lookup cookie when creating a PTP PPS source. net: sock: add trace for socket errors net: sock: introduce sk_error_report net: dsa: replay the local bridge FDB entries pointing to the bridge dev too net: dsa: ensure during dsa_fdb_offload_notify that dev_hold and dev_put are on the same dev net: dsa: include fdb entries pointing to bridge in the host fdb list net: dsa: include bridge addresses which are local in the host fdb list net: dsa: sync static FDB entries on foreign interfaces to hardware net: dsa: install the host MDB and FDB entries in the master's RX filter net: dsa: reference count the FDB addresses at the cross-chip notifier level net: dsa: introduce a separate cross-chip notifier type for host FDBs net: dsa: reference count the MDB entries at the cross-chip notifier level ...

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-06-29T22:45:27+00:00

Trivial conflict in net/netfilter/nf_tables_api.c. Duplicate fix in tools/testing/selftests/net/devlink_port_split.py - take the net-next version. skmsg, and L4 bpf - keep the bpf code but remove the flags and err params. Signed-off-by: Jakub Kicinski

net: update netdev_rx_csum_fault() print dump only once

2021-06-28T22:54:57+00:00

Printing this stack dump multiple times does not provide additional useful information, and consumes time in the data path. Printing once is sufficient. Changes v2: Format indentation properly Signed-off-by: Tanner Love Acked-by: Eric Dumazet Acked-by: Mahesh Bandewar Signed-off-by: David S. Miller