linux/net/core/dev.c, branch v6.16

net: annotate data-races around cleanup_net_task

2025-06-05T15:02:26Z

from_cleanup_net() reads cleanup_net_task locklessly. Add READ_ONCE()/WRITE_ONCE() annotations to avoid a potential KCSAN warning, even if the race is harmless. Fixes: 0734d7c3d93c ("net: expedite synchronize_net() for cleanup_net()") Signed-off-by: Eric Dumazet Reviewed-by: Jason Xing Link: https://patch.msgid.link/20250604093928.1323333-1-edumazet@google.com Signed-off-by: Jakub Kicinski

hv_netvsc: fix potential deadlock in netvsc_vf_setxdp()

2025-05-31T02:31:25Z

The MANA driver's probe registers netdevice via the following call chain: mana_probe() register_netdev() register_netdevice() register_netdevice() calls notifier callback for netvsc driver, holding the netdev mutex via netdev_lock_ops(). Further this netvsc notifier callback end up attempting to acquire the same lock again in dev_xdp_propagate() leading to deadlock. netvsc_netdev_event() netvsc_vf_setxdp() dev_xdp_propagate() This deadlock was not observed so far because net_shaper_ops was never set, and thus the lock was effectively a no-op in this case. Fix this by using netif_xdp_propagate() instead of dev_xdp_propagate() to avoid recursive locking in this path. And, since no deadlock is observed on the other path which is via netvsc_probe, add the lock exclusivly for that path. Also, clean up the unregistration path by removing the unnecessary call to netvsc_vf_setxdp(), since unregister_netdevice_many_notify() already performs this cleanup via dev_xdp_uninstall(). Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf") Cc: stable@vger.kernel.org Signed-off-by: Saurabh Sengar Tested-by: Erni Sri Satya Vennela Reviewed-by: Haiyang Zhang Reviewed-by: Subbaraya Sundeep Link: https://patch.msgid.link/1748513910-23963-1-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Jakub Kicinski

net: core: Convert dev_set_mac_address() to struct sockaddr_storage

2025-05-27T06:25:43Z

All users of dev_set_mac_address() are now using a struct sockaddr_storage. Convert the internal data type to struct sockaddr_storage, drop the casts, and update pointer types. Acked-by: Gustavo A. R. Silva Signed-off-by: Kees Cook Link: https://patch.msgid.link/20250521204619.2301870-6-kees@kernel.org Signed-off-by: Paolo Abeni

net: core: Switch netif_set_mac_address() to struct sockaddr_storage

2025-05-27T06:25:42Z

In order to avoid passing around struct sockaddr that has a size the compiler cannot reason about (nor track at runtime), convert netif_set_mac_address() to take struct sockaddr_storage. This is just a cast conversion, so there is are no binary changes. Following patches will make actual allocation changes. Acked-by: Gustavo A. R. Silva Signed-off-by: Kees Cook Link: https://patch.msgid.link/20250521204619.2301870-2-kees@kernel.org Signed-off-by: Paolo Abeni

net: add debug checks in ____napi_schedule() and napi_poll()

2025-05-22T03:44:11Z

While tracking an IDPF bug, I found that idpf_vport_splitq_napi_poll() was not following NAPI rules. It can indeed return @budget after napi_complete() has been called. Add two debug conditions in networking core to hopefully catch this kind of bugs sooner. IDPF bug will be fixed in a separate patch. [ 72.441242] repoll requested for device eth1 idpf_vport_splitq_napi_poll [idpf] but napi is not scheduled. [ 72.446291] list_del corruption. next->prev should be ff31783d93b14040, but was ff31783d93b10080. (next=ff31783d93b10080) [ 72.446659] kernel BUG at lib/list_debug.c:67! [ 72.446816] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 72.447031] CPU: 156 UID: 0 PID: 16258 Comm: ip Tainted: G W 6.15.0-dbg-DEV #1944 NONE [ 72.447340] Tainted: [W]=WARN [ 72.447702] RIP: 0010:__list_del_entry_valid_or_report (lib/list_debug.c:65) [ 72.450630] Call Trace: [ 72.450720] [ 72.450797] net_rx_action (include/linux/list.h:215 include/linux/list.h:287 net/core/dev.c:7385 net/core/dev.c:7516) [ 72.450928] ? lock_release (kernel/locking/lockdep.c:?) [ 72.451059] ? clockevents_program_event (kernel/time/clockevents.c:?) [ 72.451222] handle_softirqs (kernel/softirq.c:579) [ 72.451356] ? do_softirq (kernel/softirq.c:480) [ 72.451480] ? idpf_vc_xn_exec (drivers/net/ethernet/intel/idpf/idpf_virtchnl.c:462) idpf [ 72.451635] do_softirq (kernel/softirq.c:480) [ 72.451750] [ 72.451828] [ 72.451905] __local_bh_enable_ip (kernel/softirq.c:?) [ 72.452051] idpf_vc_xn_exec (drivers/net/ethernet/intel/idpf/idpf_virtchnl.c:462) idpf [ 72.452210] idpf_send_delete_queues_msg (drivers/net/ethernet/intel/idpf/idpf_virtchnl.c:2083) idpf [ 72.452390] idpf_vport_stop (drivers/net/ethernet/intel/idpf/idpf_lib.c:837 drivers/net/ethernet/intel/idpf/idpf_lib.c:868) idpf [ 72.452541] ? idpf_vport_stop (include/linux/bottom_half.h:? include/linux/netdevice.h:4762 drivers/net/ethernet/intel/idpf/idpf_lib.c:855) idpf [ 72.452695] idpf_initiate_soft_reset (drivers/net/ethernet/intel/idpf/idpf_lib.c:?) idpf [ 72.452867] idpf_change_mtu (drivers/net/ethernet/intel/idpf/idpf_lib.c:2189) idpf [ 72.453015] netif_set_mtu_ext (net/core/dev.c:9437) [ 72.453157] ? packet_notifier (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 net/packet/af_packet.c:4240) [ 72.453292] netif_set_mtu (net/core/dev.c:9515) [ 72.453416] dev_set_mtu (net/core/dev_api.c:?) [ 72.453534] bond_change_mtu (drivers/net/bonding/bond_main.c:4833) [ 72.453666] netif_set_mtu_ext (net/core/dev.c:9437) [ 72.453803] do_setlink (net/core/rtnetlink.c:3116) [ 72.453925] ? rtnl_newlink (net/core/rtnetlink.c:3901) [ 72.454055] ? rtnl_newlink (net/core/rtnetlink.c:3901) [ 72.454185] ? rtnl_newlink (net/core/rtnetlink.c:3901) [ 72.454314] ? trace_contention_end (include/trace/events/lock.h:122) [ 72.454467] ? __mutex_lock (arch/x86/include/asm/preempt.h:85 kernel/locking/mutex.c:611 kernel/locking/mutex.c:746) [ 72.454597] ? cap_capable (include/trace/events/capability.h:26) [ 72.454721] ? security_capable (security/security.c:?) [ 72.454857] rtnl_newlink (net/core/rtnetlink.c:?) [ 72.454982] ? lock_is_held_type (kernel/locking/lockdep.c:5599 kernel/locking/lockdep.c:5938) [ 72.455121] ? __lock_acquire (kernel/locking/lockdep.c:?) [ 72.455256] ? __change_page_attr_set_clr (arch/x86/mm/pat/set_memory.c:685) [ 72.455438] ? __lock_acquire (kernel/locking/lockdep.c:?) [ 72.455582] ? rtnetlink_rcv_msg (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 net/core/rtnetlink.c:6885) [ 72.455721] ? lock_acquire (kernel/locking/lockdep.c:5866) [ 72.455848] ? rtnetlink_rcv_msg (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 net/core/rtnetlink.c:6885) [ 72.455987] ? lock_release (kernel/locking/lockdep.c:?) [ 72.456117] ? rcu_read_unlock (include/linux/rcupdate.h:341 include/linux/rcupdate.h:871) [ 72.456249] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3956) [ 72.456388] rtnetlink_rcv_msg (net/core/rtnetlink.c:6955) [ 72.456526] ? rtnetlink_rcv_msg (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 net/core/rtnetlink.c:6885) [ 72.456671] ? lock_acquire (kernel/locking/lockdep.c:5866) [ 72.456802] ? net_generic (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 include/net/netns/generic.h:45) [ 72.456929] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6858) [ 72.457082] netlink_rcv_skb (net/netlink/af_netlink.c:2534) [ 72.457212] netlink_unicast (net/netlink/af_netlink.c:1313) [ 72.457344] netlink_sendmsg (net/netlink/af_netlink.c:1883) [ 72.457476] __sock_sendmsg (net/socket.c:712) [ 72.457602] ____sys_sendmsg (net/socket.c:?) [ 72.457735] ? _copy_from_user (arch/x86/include/asm/uaccess_64.h:126 arch/x86/include/asm/uaccess_64.h:134 arch/x86/include/asm/uaccess_64.h:141 include/linux/uaccess.h:178 lib/usercopy.c:18) [ 72.457875] ___sys_sendmsg (net/socket.c:2620) [ 72.458042] ? __call_rcu_common (arch/x86/include/asm/irqflags.h:42 arch/x86/include/asm/irqflags.h:119 arch/x86/include/asm/irqflags.h:159 kernel/rcu/tree.c:3107) [ 72.458185] ? mntput_no_expire (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 fs/namespace.c:1457) [ 72.458324] ? lock_acquire (kernel/locking/lockdep.c:5866) [ 72.458451] ? mntput_no_expire (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 fs/namespace.c:1457) [ 72.458588] ? lock_release (kernel/locking/lockdep.c:?) [ 72.458718] ? mntput_no_expire (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 fs/namespace.c:1457) [ 72.458856] __x64_sys_sendmsg (net/socket.c:2652) [ 72.458997] ? do_syscall_64 (arch/x86/include/asm/irqflags.h:42 arch/x86/include/asm/irqflags.h:119 include/linux/entry-common.h:198 arch/x86/entry/syscall_64.c:90) [ 72.459136] do_syscall_64 (arch/x86/entry/syscall_64.c:?) [ 72.459259] ? exc_page_fault (arch/x86/mm/fault.c:1542) [ 72.459387] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 72.459555] RIP: 0033:0x7fd15f17cbd0 Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20250520121908.1805732-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: use skb_crc32c() in skb_crc32c_csum_help()

2025-05-21T22:39:59Z

Instead of calling __skb_checksum() with a skb_checksum_ops struct that does CRC32C, just call the new function skb_crc32c(). This is faster and simpler. Signed-off-by: Eric Biggers Reviewed-by: Hannes Reinecke Link: https://patch.msgid.link/20250519175012.36581-4-ebiggers@kernel.org Signed-off-by: Jakub Kicinski

net: introduce CONFIG_NET_CRC32C

2025-05-21T22:39:58Z

Add a hidden kconfig symbol NET_CRC32C that will group together the functions that calculate CRC32C checksums of packets, so that these don't have to be built into NET-enabled kernels that don't need them. Make skb_crc32c_csum_help() (which is called only when IP_SCTP is enabled) conditional on this symbol, and make IP_SCTP select it. Signed-off-by: Eric Biggers Reviewed-by: Hannes Reinecke Link: https://patch.msgid.link/20250519175012.36581-2-ebiggers@kernel.org Signed-off-by: Jakub Kicinski

selftests: net: validate team flags propagation

2025-05-21T01:12:58Z

Cover three recent cases: 1. missing ops locking for the lowers during netdev_sync_lower_features 2. missing locking for dev_set_promiscuity (plus netdev_ops_assert_locked with a comment on why/when it's needed) 3. rcu lock during team_change_rx_flags Verified that each one triggers when the respective fix is reverted. Not sure about the placement, but since it all relies on teaming, added to the teaming directory. One ugly bit is that I add NETIF_F_LRO to netdevsim; there is no way to trigger netdev_sync_lower_features without it. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250516232205.539266-1-stfomichev@gmail.com Signed-off-by: Jakub Kicinski

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

2025-05-15T18:28:30Z

Cross-merge networking fixes after downstream PR (net-6.15-rc7). Conflicts: tools/testing/selftests/drivers/net/hw/ncdevmem.c 97c4e094a4b2 ("tests/ncdevmem: Fix double-free of queue array") 2f1a805f32ba ("selftests: ncdevmem: Implement devmem TCP TX") https://lore.kernel.org/20250514122900.1e77d62d@canb.auug.org.au Adjacent changes: net/core/devmem.c net/core/devmem.h 0afc44d8cdf6 ("net: devmem: fix kernel panic when netlink socket close after module unload") bd61848900bf ("net: devmem: Implement TX path") Signed-off-by: Jakub Kicinski

xdp: Use nested-BH locking for system_page_pool

2025-05-15T13:23:31Z

system_page_pool is a per-CPU variable and relies on disabled BH for its locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this data structure requires explicit locking. Make a struct with a page_pool member (original system_page_pool) and a local_lock_t and use local_lock_nested_bh() for locking. This change adds only lockdep coverage and does not alter the functional behaviour for !PREEMPT_RT. Cc: Andrew Lunn Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Jesper Dangaard Brouer Cc: John Fastabend Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Sebastian Andrzej Siewior Link: https://patch.msgid.link/20250512092736.229935-6-bigeasy@linutronix.de Signed-off-by: Paolo Abeni