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path: root/net/ipv6/ip6_gre.c
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11 daysMerge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni
Merge in late fixes in preparation for the net-next PR. Conflicts: net/netfilter/nf_conntrack_netlink.c cd37ab22a74e0 ("netfilter: nf_conntrack_netlink: fix inverted IPv6 tuple filter") 1ae2d094b0200 ("netfilter: ctnetlink: fix inverted IPv6 address match in dump filter") Adjacent changes: drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c 8830e65ed46de ("net: use assign_bit() where applicable") 07bd391eb957 ("octeontx2-af: Fix CQ enable state tracking after AQ writes") net/core/sock.c 31c5ea8a3296 ("ipv6: Remove IPV6_ADDRFORM.") 31b564f70d88 ("net: use the full socket in sk_mc_loop()") net/mptcp/protocol.h 0cb6910130a3 ("mptcp: remove thmac from subflow ctx") 7538fa33bb2f ("mptcp: fix subflow bitfield misuse") Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-10-15net: erspan: set lltx to avoid sch_direct_xmit deadlockYun Zhou
The ERSPAN xmit path re-enters the network stack, causing nested acquisition of _xmit_lock on the underlay device while already holding the ERSPAN device's _xmit_lock, creating an ABBA deadlock. This happens for both IPv4 ERSPAN (erspan_xmit() -> ip_tunnel_xmit()) and IPv6 ERSPAN (ip6erspan_tunnel_xmit() -> ip6_tnl_xmit()): sch_direct_xmit [lock erspan] -> erspan_xmit -> ip_tunnel_xmit -> ip_output -> __dev_queue_xmit -> sch_direct_xmit [lock underlay] sch_direct_xmit [lock erspan] -> ip6erspan_tunnel_xmit -> ip6_tnl_xmit -> ip6_output -> __dev_queue_xmit -> sch_direct_xmit [lock underlay] Set dev->lltx = true so HARD_TX_LOCK() skips the spinlock for ERSPAN. This is safe as the ERSPAN xmit path has no shared mutable state: o_seqno is atomic, TX stats are per-CPU u64_stats, dst_cache is per-CPU, and o_flags is no longer modified in the xmit path since commit 9958e69b9893 ("gre: fix ERSPAN o_flags race/corruption in xmit and fill_info"). GRETAP, the sibling device with identical xmit structure, already sets lltx. Reported-by: syzbot+9bda1b9fbb7fbdf9b62b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9bda1b9fbb7fbdf9b62b Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN") Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support") Cc: stable@vger.kernel.org # 9958e69b9893 ("gre: fix ERSPAN o_flags race/corruption in xmit and fill_info") Cc: stable@vger.kernel.org Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261008093824.119453-1-yun.zhou@windriver.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.3-rc7). Conflicts: include/net/strparser.h 0984ebc631792 ("strparser: make sure __strp_recv isn't running before tearing down the parser") 02fd0a2111374 ("net: strparser: removed the aborted bit and aborts counter") https://lore.kernel.org/asYfmLsfy-SCxXjr@sirena.co.uk Adjacent changes: Documentation/networking/strparser.rst 5f193cdabf25 ("docs: networking: strparser: remove general mode") 0984ebc63179 ("strparser: make sure __strp_recv isn't running before tearing down the parser") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-08ip6_gre: let collect_md ip6gretap send from the unspecified addressAnton Danilov
ip6gre_xmit_ipv6() drops an IPv6 packet whose source address equals the tunnel remote, to avoid a trivial tunneling loop. On a collect_md ip6gretap device t->parms.raddr is not the exit point: the outer destination comes from the per-packet tunnel metadata. Such devices are normally created without a remote, so raddr is ::, and the check never matches a real tunnel endpoint. It matches every frame sent from the unspecified address instead. On an L2 tunnel those frames are regular link traffic. Duplicate Address Detection sends its Neighbor Solicitations from :: (RFC 4862, section 5.4.2), and MLD reports are sent from :: while an interface has no link-local address yet (RFC 3590, section 4). Frames bridged into a collect_md ip6gretap device, e.g. with tc tunnel_key and mirred, are dropped even though they carry valid metadata, so DAD cannot detect a duplicate address on the other side of the tunnel. Skip the check for collect_md devices of type ARPHRD_ETHER. It stays for L3 ip6gre, where sending a packet with an unspecified source means forwarding it (RFC 4291, section 2.5.2), and for ip6gretap without collect_md. ip6erspan does not run this check in collect_md mode either. Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261005191227.894665-1-littlesmilingcloud@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-07ip_tunnel: make __iptunnel_pull_header() return a drop reasonAnton Danilov
__iptunnel_pull_header() returns -ENOMEM whenever it fails. It can fail in two pskb_may_pull() calls, one for the tunnel header and one for the inner Ethernet header of ETH_P_TEB, and in the skb_unclone() done for GSO packets. pskb_may_pull() fails when the packet is shorter than the requested length as well as when pulling from the frags cannot allocate, so a truncated packet and an allocation failure look the same to the callers. The ones that report a drop reason can only pick SKB_DROP_REASON_NOMEM, as vxlan_rcv() does, and so would the GRE receive paths once they report drop reasons. In ip6_gre, gre_rcv() pulls the header before the tunnel lookup, so a packet from any sender whose ETH_P_TEB inner Ethernet header or WCCPv2 extra word is cut short would be reported as an out of memory condition. Make __iptunnel_pull_header() and iptunnel_pull_header() return the reason pskb_may_pull_reason() already computes, SKB_DROP_REASON_NOMEM when skb_unclone() fails, and SKB_NOT_DROPPED_YET on success. A failure is still non-zero, so the callers that only test the result keep working. Three callers, in ip_gre and ip6_gre, test it with "< 0" instead; the enum has no negative values, so that test would always be false, and the compiler does not warn about it. Make them test for a non-zero value. vxlan_rcv() keeps reporting NOMEM for any failure until the next patch has it report the returned reason. Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261005201417.906344-3-littlesmilingcloud@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-06ip6_gre: remove obsolete ERSPAN PMTU updateDaehyeon Ko
A tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb, and mirred can redirect it to a native ip6erspan device. The legacy PMTU update in ip6erspan_tunnel_xmit() treats that metadata dst as a route. Since it has no output device, dst_dev(dst)->mtu dereferences NULL. On v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used self-created user and network namespaces to trigger: KASAN: null-ptr-deref RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0 Kernel panic - not syncing: Fatal exception in interrupt The update is obsolete. Commit fe1a4ca0a2b7 ("ip6_gre: process toobig in a better way") changed IPv6 GRE Too Big handling to update the underlay route and removed the equivalent block from __gre6_xmit(). ip6_tnl_xmit() then propagates the underlay PMTU to the overlay route. Remove the stale ERSPAN copy and its now-unused dst variable. This eliminates the metadata-dst dereference and keeps ERSPAN aligned with IPv6 GRE PMTU handling. Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support") Cc: stable@vger.kernel.org Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261002033058.358137-1-4ncienth@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.3-rc5). Conflicts: drivers/net/mdio/mdio-realtek-rtl9300.c 89a8a1eef2d44 ("net: mdio: realtek-rtl9300: fix RTL931x C22 extended page selection") cc3cb8db1eef9 ("net: mdio: realtek-rtl9300: Add page tracking") https://lore.kernel.org/arUZOqy73bE2pp0w@sirena.org.uk net/8021q/vlan_dev.c cd5dd68267c4 ("vlan: ensure sufficient headroom in vlan_dev_hard_header()") ca6ff8dd70eb ("vlan: annotate data-races in vlan_dev_priv fields") Adjacent changes: net/ipv6/ip6_gre.c dd47bcf279f1 ("ip6_gre: Call ip6erspan_tunnel_unlink_md() in ip6erspan_changelink().") cce829e2aa1d ("ip6_gre: Protect ip6gre_net.tunnels[][] with mutex.") drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b5d9e9d4d0c1 ("eth: fbnic: use the Rx queue napi pointer to find the napi vector") c0aca269ec07 ("eth: fbnic: Make Rx completion coalescing configurable") drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c d68acbf93531 ("net: stmmac: selftests: Support running selftests on DSA conduits") 85ca3292d7a3 ("net: stmmac: Remove ARP offload code") drivers/net/ethernet/wangxun/libwx/wx_hw.c 3173cba11701 ("net: libwx: fix races in Tx timestamp handling") 7042c8c193e5 ("net: libwx: rename wx_pf_flags to wx_flags") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Support per-netns device unregistration.Kuniyuki Iwashima
ip6gre_exit_rtnl_net() iterates ip6gre devices and variants whose link_net is dying and queues them for destruction. The devices may reside in different netns. Let's use unregister_netdevice_queue_net() to support per-netns device unregistration. Even after ip6gre_exit_rtnl_net() queues a cross-netns ip6gre device, ip6gre_changelink_common(), ip6gre_dellink(), and ip6gre_tunnel_siocdevprivate() could be called concurrently for it (once RTNL is removed). In such a case, __rtnl_net_unlock() will perform the unregistration. Also, ip6gre_tunnel_siocdevprivate() needs to check check_net(t->net), otherwise it could create a new dev in dying netns after ip6gre_exit_rtnl_net(). In the example below, we can see the fallback tunnel device (ip6gre0) and the cross-netns device (ip6gre1) are unregistered by different processes: # bpftrace -e '#include <linux/netdevice.h> kprobe:ip6gre_tunnel_uninit { $dev = (struct net_device *)arg0; printf("PID: %d | DEV: %s%s\n", pid, $dev->name, kstack()); } kprobe:ip6gre_exit_rtnl_net { printf("PID: %d%s\n", pid, kstack()); }' & # ip netns add ns1 # ip netns add ns2 # ip -n ns1 link add name ip6gre1 link-netns ns2 \ type ip6gre local 2001:9292::1 remote 2001:9292::2 # ip netns del ns2 PID: 12 ip6gre_exit_rtnl_net+5 ops_undo_list+702 cleanup_net+1122 ... PID: 12 | DEV: ip6gre0 <------ fallback device (itn->fb_tunnel_dev). ip6gre_tunnel_uninit+5 unregister_netdevice_many_notify+7137 unregister_netdevice_many_net+1050 __rtnl_net_unlock+37 ops_undo_list+754 cleanup_net+1122 ... PID: 10 | DEV: ip6gre1 ip6gre_tunnel_uninit+5 unregister_netdevice_many_notify+7137 unregister_netdevice_many_net+1050 rtnl_net_work_func+136 Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260916230353.367014-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Protect ip6gre_net.tunnels[][] with mutex.Kuniyuki Iwashima
struct ip6_tnl.net is the netns where encapsulated packets flow into. struct ip6_tnl is linked to ip6gre_net.tunnels[][] of netns. During netns dismantle or module unload, ip6gre_exit_rtnl_net() iterates the list and queues devices for destruction regardless of the devices' netns. Thus, once RTNL is removed, the list can be modified concurrently from different netns due to device removal. Let's protect it with per-netns mutex. Note that dev_siocdevprivate() calls netdev_lock_ops() but it must be NOP for tunnel devices to avoid AB-BA deadlock. DEBUG_NET_WARN_ON_ONCE() is added to annotate the locking explicitly. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260916230353.367014-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Unlink ip6gre_tunnel_unlink() from ->dellink().Kuniyuki Iwashima
With the previous patch, itn->fb_tunnel_dev can be removed via ->dellink(). However, ioctl(SIOCDELTUNNEL) still uses unregister_netdevice(), which requires ip6gre_tunnel_unlink() in ip6gre_tunnel_uninit(). Let's use __ip6gre_dellink() everywhere to remove ip6gre (and variant) devices and remove ip6gre_tunnel_unlink() and ip6gre_tunnel_unlink_md() in ip6gre_tunnel_uninit(). ip6erspan_tunnel_uninit() is also changed accordingly. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260916230353.367014-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Clear ign->fb_tunnel_dev in ip6gre_exit_rtnl_net().Kuniyuki Iwashima
ip6gre_dellink() ignores itn->fb_tunnel_dev, so the per-netns fallback tunnel device cannot be removed by userspace. This also makes default_device_exit_batch() impossible to remove the device since it calls ->dellink(). So, ip6gre_exit_rtnl_net() has to iterate devices in the dying netns and call unregister_netdevice_queue() directly, and ip6gre_tunnel_unlink() must be called at ->ndo_uninit(). For per-netns device unregistration, we want to check if the device is being removed in ->dellink(), for which we must call ip6gre_tunnel_unlink() before unregister_netdevice_queue(). As a prep, let's set itn->fb_tunnel_dev to NULL and remove remove for_each_netdev_safe() in ip6gre_exit_rtnl_net(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260916230353.367014-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Convert ip6gre_net.tunnels[][] to hlist.Kuniyuki Iwashima
struct ip6_tnl has a pointer to the next one. Single linked list requires O(n) iteration for device removal and IPv4 tunnel already uses hlist for its hash table. Let's convert ip6gre_net.tunnels[][] to hlist. Once we convert other users (ip6_tunnel.c, sit.c), we can remove the *next pointer from struct ip6_tnl. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260916230353.367014-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Initialise ign->tunnels_wc[0] before register_netdev().Kuniyuki Iwashima
ip6gre_init_net() links the fallback device ip6gre0 to ign->tunnels_wc[0] after publishing it by register_netdev(). While ip6_gre module is being loaded, there is a small race window. If ioctl(SIOCADDTUNNEL) is called before ip6gre0 is linked to the hash table, a new device could be linked to ign->tunnels_wc[0]. Then, the fallback device overwrites ign->tunnels_wc[0], and the new device will be no longer found by ip6gre_tunnel_lookup(), resulting in no RX. Let's link the fallback device before register_netdev(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260916230353.367014-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-18ip6_gre: Call ip6erspan_tunnel_unlink_md() in ip6erspan_changelink().Kuniyuki Iwashima
The cited commit accidentally added ip6gre_tunnel_unlink_md() in ip6erspan_changelink(). Let's correct it to ip6erspan_tunnel_unlink_md(). Fixes: b80d0b93b991 ("net: ip6_gre: fix tunnel metadata device sharing.") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260916230927.378957-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-31ip6_gre: check tunnel info before xmit in ip6gre_tunnel_xmitEric Dumazet
Shuangpeng Bai reported a KASAN slab-use-after-free in ip6gre_tunnel_xmit(). The precise KASAN bug was caused by ip6_tnl_xmit() consuming the skb during headroom expansion and returning an error, while ip6gre_tunnel_xmit() still held the stale pointer and called skb_tunnel_info_txcheck(skb) at tx_err. That specific bug was fixed by commit 87f21b59ddc6 ("ip6_tunnel: use skb_cow_head() in ip6_tnl_xmit()"). However, calling skb_tunnel_info_txcheck(skb) at the tx_err label after the transmission attempt remains problematic: Downstream helpers like ip6_tnl_xmit() call skb_scrub_packet(), which drops the skb's metadata_dst before transmission. If an error occurs later during transmit, inspecting skb at tx_err sees a scrubbed dst and misclassifies tx_errors vs tx_dropped. Commit e5f7e211b6aa ("ip6gre: avoid tx_error when sending MLD/DAD on external tunnels") already handled this correctly in ip6erspan_tunnel_xmit() by checking and caching tun_info before transmit. Align ip6gre_tunnel_xmit() with ip6erspan_tunnel_xmit() by caching tun_info before xmit and checking it at tx_err. Fixes: e5f7e211b6aa ("ip6gre: avoid tx_error when sending MLD/DAD on external tunnels") Reported-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com> Closes: https://lore.kernel.org/netdev/20260819062224.3197349-1-shuangpeng.kernel@gmail.com/ Cc: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260828103731.1951815-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in late fixes in preparation for the net-next PR. Conflicts: drivers/dpll/dpll_core.c drivers/dpll/dpll_netlink.c 33f016b23a219 ("dpll: fix NULL deref in dpll_device_ops() during teardown race") b1d0c412088e3 ("dpll: add STATE_CONNECTED_OVERRIDE pin capability") https://lore.kernel.org/aoR9YYY2P5--3x0N@sirena.org.uk https://lore.kernel.org/aoR9VmKllVGwmQn_@sirena.org.uk No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-18net: cap advertised IP tunnel headroomZhiling Zou
IP tunnel devices derive their advertised needed_headroom from lower output devices. A stack of user-created devices can make the derived value larger than the 16-bit skb header offsets can represent. Once IP output reserves it, skb head expansion can wrap those offsets. The runtime transmit path already caps a growing needed_headroom at 512. Apply the same cap when tunnel configuration publishes needed_headroom derived from a lower output device. Capping the advertised value is safe: IP tunnel transmit still expands the skb when a packet needs more headroom. A nonsensical stacked configuration can therefore incur an extra reallocation, but it cannot publish an unbounded reservation to upper layers. Fixes: 1a37e412a022 ("net: Use 16bits for *_headers fields of struct skbuff") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/ba04a1fd6bfae2377607fad5d8f80f7eb80fd4c4.1786542637.git.zhilinz@nebusec.ai Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-18ip6_gre: fix hardware header length for NBMA tunnelsZhiling Zou
ip6gre_tnl_link_config_route() accumulates the lower device's hardware header length into dev->hard_header_len whenever header_ops is set. This is incorrect for both users of header_ops. ip6gretap and ip6erspan have a fixed Ethernet hardware header length. For an NBMA ip6gre tunnel, ip6gre_header() creates only the GRE header, the optional FOU or GUE header, and the outer IPv6 header. The lower device header is headroom needed later, not part of the tunnel device's hardware header. Keep the lower device header in needed_headroom. Set hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, and leave the fixed Ethernet header length unchanged for tap and erspan devices. Fixes: 832ba596494b ("net: ip6_gre: set dev->hard_header_len when using header_ops") Cc: stable@vger.kernel.org Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/64b46542bbe1701f07702aaa50273e2a87903db5.1786542637.git.zhilinz@nebusec.ai Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-14gre: fix ERSPAN o_flags race/corruption in xmit and fill_infoEric Dumazet
For IPv4 ERSPAN: In erspan_xmit(), the driver clears IP_TUNNEL_SEQ_BIT (for version 0) and IP_TUNNEL_KEY_BIT directly in the shared tunnel->parms.o_flags structure. Since transmit paths can run locklessly and concurrently, this leads to a data race. Furthermore, modifying tunnel->parms.o_flags permanently alters the tunnel configuration. To work around this, erspan_fill_info() (which reports config to userspace) was setting IP_TUNNEL_KEY_BIT back. If erspan_fill_info (running under RTNL) and erspan_xmit (running locklessly) race, erspan_xmit might see IP_TUNNEL_KEY_BIT set when it shouldn't, leading to GRE header corruption (injecting a key field into the ERSPAN GRE header). Fix this by: 1) Passing flags as an argument to __gre_xmit(). 2) Using local stack flags in ipgre_xmit(), gre_tap_xmit(), and erspan_xmit() to prevent TOCTOU data races with concurrent configuration updates, and passing them to __gre_xmit(). 3) Removing the racy modification of t->parms.o_flags in erspan_fill_info(). 4) Forcing IP_TUNNEL_KEY_BIT in the reported flags for ERSPAN locally in ipgre_fill_info(). For IPv6 ERSPAN: ip6erspan_tunnel_xmit() was locklessly clearing IP_TUNNEL_KEY_BIT in t->parms.o_flags even though it does not use these flags for building the GRE header (it uses local flags). This permanently corrupts the configuration and races with ip6gre_fill_info() which reads it. Remove the redundant and racy modification. This should remove false sharing in a fast path. Add const qualifiers in ipgre_fill_info(), erspan_fill_info() and ip6gre_fill_info() to clarify that these methods are not supposed to write any live parameters. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260812142257.21283-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23net: gre: fix lltx regression for GRE tunnels with SEQ/CSUMYun Zhou
Before commit 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx"), NETIF_F_LLTX was set unconditionally in both __gre_tunnel_init() and ip6gre_tnl_init_features() alongside GRE_FEATURES: dev->features |= GRE_FEATURES | NETIF_F_LLTX; When that commit converted NETIF_F_LLTX to the dev->lltx flag, it placed 'dev->lltx = true' after the SEQ/CSUM early returns instead of before them. This causes GRE/GRETAP/ip6gre tunnels with SEQ or CSUM+encap to lose lockless TX, reintroducing _xmit_lock acquisition around their ndo_start_xmit. Since GRE xmit re-enters the stack via ip_tunnel_xmit(), holding _xmit_lock risks ABBA deadlock with the underlay device. CPU0 CPU1 ---- ---- lock(&qdisc_xmit_lock_key#6); lock(&qdisc_xmit_lock_key#3); lock(&qdisc_xmit_lock_key#6); lock(&qdisc_xmit_lock_key#3); Fix by moving dev->lltx = true before the early returns in both functions, restoring the original unconditional behavior. Fixes: 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260713150945.1779628-1-yun.zhou@windriver.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-17net: ip6_gre: require CAP_NET_ADMIN in the device netns for changelinkMaoyi Xie
ip6gre_changelink() and ip6erspan_changelink() operate on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate both ops on rtnl_dev_link_net_capable() at their top, before any attribute is parsed. Reported-by: Xiao Liang <shaw.leon@gmail.com> Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: 690afc165bb3 ("net: ip6_gre: fix moving ip6gre between namespaces") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260612085941.3158249-6-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11ip6_tunnel: annotate data-races around t->err_count and t->err_timeEric Dumazet
ip6_tnl_xmit() and ipip6_tunnel_xmit() run locklessly (dev->lltx == true). ip6gre_err() and ipip6_err() also run locklessly. We need to add READ_ONCE() and WRITE_ONCE() annotations around t->err_count and t->err_time. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260610171458.1359630-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11ip6_tunnel: do not use dst6_mtu() in ip4ip6_err() and ip6erspan_tunnel_xmit()Eric Dumazet
This is a minor performance / conceptual fix. 1) ip6erspan_tunnel_xmit() ERSPAN tunnel can mirror both IPv4 and IPv6 traffic, skb (the packet being mirrored) can be an IPv4 packet, and thus dst can be an IPv4 destination entry Use dst_mtu() which contains generic logic for both families. 2) ip4ip6_err() skb2 has been prepared as an IPv4 packet, and its destination is an IPv4 route. dst6_mtu() is optimized for IPv6 destinations and uses INDIRECT_CALL_1 to call ip6_mtu() directly if the ops match. We should use dst4_mtu() instead. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260609091337.2672441-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-02ip6_gre: Use cached t->net in ip6erspan_changelink().Maoyi Xie
After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape. Fixes: 2d665034f239 ("net: ip6_gre: Fix ip6erspan hlen calculation") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260430103318.3206018-1-maoyi.xie@ntu.edu.sg Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-12gre: Count GRE packet dropsGal Pressman
GRE is silently dropping packets without updating statistics. In case of drop, increment rx_dropped counter to provide visibility into packet loss. For the case where no GRE protocol handler is registered, use rx_nohandler. Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Nimrod Oren <noren@nvidia.com> Signed-off-by: Gal Pressman <gal@nvidia.com> Link: https://patch.msgid.link/20260409090945.1542440-1-gal@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-02ipv6: use dst6_mtu() instead of dst_mtu()Eric Dumazet
When we expect an IPv6 dst, use dst6_mtu() instead of dst_mtu() to save some code space. Due to current dst6_mtu() implementation, only convert users in IPv6 stack. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-12-23erspan: Initialize options_len before referencing options.Frode Nordahl
The struct ip_tunnel_info has a flexible array member named options that is protected by a counted_by(options_len) attribute. The compiler will use this information to enforce runtime bounds checking deployed by FORTIFY_SOURCE string helpers. As laid out in the GCC documentation, the counter must be initialized before the first reference to the flexible array member. After scanning through the files that use struct ip_tunnel_info and also refer to options or options_len, it appears the normal case is to use the ip_tunnel_info_opts_set() helper. Said helper would initialize options_len properly before copying data into options, however in the GRE ERSPAN code a partial update is done, preventing the use of the helper function. Before this change the handling of ERSPAN traffic in GRE tunnels would cause a kernel panic when the kernel is compiled with GCC 15+ and having FORTIFY_SOURCE configured: memcpy: detected buffer overflow: 4 byte write of buffer size 0 Call Trace: <IRQ> __fortify_panic+0xd/0xf erspan_rcv.cold+0x68/0x83 ? ip_route_input_slow+0x816/0x9d0 gre_rcv+0x1b2/0x1c0 gre_rcv+0x8e/0x100 ? raw_v4_input+0x2a0/0x2b0 ip_protocol_deliver_rcu+0x1ea/0x210 ip_local_deliver_finish+0x86/0x110 ip_local_deliver+0x65/0x110 ? ip_rcv_finish_core+0xd6/0x360 ip_rcv+0x186/0x1a0 Cc: stable@vger.kernel.org Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-counted_005fby-variable-attribute Reported-at: https://launchpad.net/bugs/2129580 Fixes: bb5e62f2d547 ("net: Add options as a flexible array to struct ip_tunnel_info") Signed-off-by: Frode Nordahl <fnordahl@ubuntu.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20251213101338.4693-1-fnordahl@ubuntu.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-22ip6_gre: make ip6gre_header() robustEric Dumazet
Over the years, syzbot found many ways to crash the kernel in ip6gre_header() [1]. This involves team or bonding drivers ability to dynamically change their dev->needed_headroom and/or dev->hard_header_len In this particular crash mld_newpack() allocated an skb with a too small reserve/headroom, and by the time mld_sendpack() was called, syzbot managed to attach an ip6gre device. [1] skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:213 ! <TASK> skb_under_panic net/core/skbuff.c:223 [inline] skb_push+0xc3/0xe0 net/core/skbuff.c:2641 ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371 dev_hard_header include/linux/netdevice.h:3436 [inline] neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618 neigh_output include/net/neighbour.h:556 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318 mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693 Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: syzbot+43a2ebcf2a64b1102d64@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/693b002c.a70a0220.33cd7b.0033.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251211173550.2032674-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-19ipv6: ip6_gre: replace strcpy with strscpy for tunnel nameMiguel García
Replace the strcpy() call that copies the device name into tunnel->parms.name with strscpy(), to avoid potential overflow and guarantee NULL termination. This uses the two-argument form of strscpy(), where the destination size is inferred from the array type. Destination is tunnel->parms.name (size IFNAMSIZ). Tested in QEMU (Alpine rootfs): - Created IPv6 GRE tunnels over loopback - Assigned overlay IPv6 addresses - Verified bidirectional ping through the tunnel - Changed tunnel parameters at runtime (`ip -6 tunnel change`) Signed-off-by: Miguel García <miguelgarciaroman8@gmail.com> Link: https://patch.msgid.link/20250818220203.899338-1-miguelgarciaroman8@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-22ip6_gre: Factor out common ip6gre tunnel match into helperYue Haibing
Extract common ip6gre tunnel match from ip6gre_tunnel_lookup() into new helper function ip6gre_tunnel_match() to reduce code duplication. No functional change intended. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250719081551.963670-1-yuehaibing@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-07-02ipv6: adopt dst_dev() helperEric Dumazet
Use the new helper as a step to deal with potential dst->dev races. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250630121934.3399505-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14ipv6: Convert tunnel devices' ->exit_batch_rtnl() to ->exit_rtnl().Kuniyuki Iwashima
The following functions iterates the dying netns list and performs the same operations for each netns. * ip6gre_exit_batch_rtnl() * ip6_tnl_exit_batch_rtnl() * vti6_exit_batch_rtnl() * sit_exit_batch_rtnl() Let's use ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250411205258.63164-8-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-08net: move misc netdev_lock flavors to a separate headerJakub Kicinski
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>
2025-03-04net: rename netns_local to netns_immutableNicolas Dichtel
The name 'netns_local' is confusing. A following commit will export it via netlink, so let's use a more explicit name. Reported-by: Eric Dumazet <edumazet@google.com> Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-02-21net: ipv6: Use link netns in newlink() of rtnl_link_opsXiao Liang
When link_net is set, use it as link netns instead of dev_net(). This prepares for rtnetlink core to create device in target netns directly, in which case the two namespaces may be different. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-9-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-21net: ipv6: Init tunnel link-netns before registering devXiao Liang
Currently some IPv6 tunnel drivers set tnl->net to dev_net(dev) in ndo_init(), which is called in register_netdevice(). However, it lacks the context of link-netns when we enable cross-net tunnels at device registration time. Let's move the init of tunnel link-netns before register_netdevice(). ip6_gre has already initialized netns, so just remove the redundant assignment. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-8-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-21rtnetlink: Pack newlink() params into structXiao Liang
There are 4 net namespaces involved when creating links: - source netns - where the netlink socket resides, - target netns - where to put the device being created, - link netns - netns associated with the device (backend), - peer netns - netns of peer device. Currently, two nets are passed to newlink() callback - "src_net" parameter and "dev_net" (implicitly in net_device). They are set as follows, depending on netlink attributes in the request. +------------+-------------------+---------+---------+ | peer netns | IFLA_LINK_NETNSID | src_net | dev_net | +------------+-------------------+---------+---------+ | | absent | source | target | | absent +-------------------+---------+---------+ | | present | link | link | +------------+-------------------+---------+---------+ | | absent | peer | target | | present +-------------------+---------+---------+ | | present | peer | link | +------------+-------------------+---------+---------+ When IFLA_LINK_NETNSID is present, the device is created in link netns first and then moved to target netns. This has some side effects, including extra ifindex allocation, ifname validation and link events. These could be avoided if we create it in target netns from the beginning. On the other hand, the meaning of src_net parameter is ambiguous. It varies depending on how parameters are passed. It is the effective link (or peer netns) by design, but some drivers ignore it and use dev_net instead. To provide more netns context for drivers, this patch packs existing newlink() parameters, along with the source netns, link netns and peer netns, into a struct. The old "src_net" is renamed to "net" to avoid confusion with real source netns, and will be deprecated later. The use of src_net are converted to params->net trivially. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-03netdev_features: convert NETIF_F_NETNS_LOCAL to dev->netns_localAlexander Lobakin
"Interface can't change network namespaces" is rather an attribute, not a feature, and it can't be changed via Ethtool. Make it a "cold" private flag instead of a netdev_feature and free one more bit. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-09-03netdev_features: convert NETIF_F_LLTX to dev->lltxAlexander Lobakin
NETIF_F_LLTX can't be changed via Ethtool and is not a feature, rather an attribute, very similar to IFF_NO_QUEUE (and hot). Free one netdev_features_t bit and make it a "hot" private flag. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-15net: ip6_gre: Remove generic .ndo_get_stats64Breno Leitao
Commit 3e2f544dd8a33 ("net: get stats64 if device if driver is configured") moved the callback to dev_get_tstats64() to net core, so, unless the driver is doing some custom stats collection, it does not need to set .ndo_get_stats64. Since this driver is now relying in NETDEV_PCPU_STAT_TSTATS, then, it doesn't need to set the dev_get_tstats64() generic .ndo_get_stats64 function pointer. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-15net: ipv6_gre: Do not use custom stat allocatorBreno Leitao
With commit 34d21de99cea9 ("net: Move {l,t,d}stats allocation to core and convert veth & vrf"), stats allocation could be done on net core instead of in this driver. With this new approach, the driver doesn't have to bother with error handling (allocation failure checking, making sure free happens in the right spot, etc). This is core responsibility now. Remove the allocation in the ip6_gre and leverage the network core allocation instead. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/ip_gre.c 17af420545a7 ("erspan: make sure erspan_base_hdr is present in skb->head") 5832c4a77d69 ("ip_tunnel: convert __be16 tunnel flags to bitmaps") https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/ Adjacent changes: net/ipv6/ip6_fib.c d21d40605bca ("ipv6: Fix infinite recursion in fib6_dump_done().") 5fc68320c1fb ("ipv6: remove RTNL protection from inet6_dump_fib()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-01ip_tunnel: convert __be16 tunnel flags to bitmapsAlexander Lobakin
Historically, tunnel flags like TUNNEL_CSUM or TUNNEL_ERSPAN_OPT have been defined as __be16. Now all of those 16 bits are occupied and there's no more free space for new flags. It can't be simply switched to a bigger container with no adjustments to the values, since it's an explicit Endian storage, and on LE systems (__be16)0x0001 equals to (__be64)0x0001000000000000. We could probably define new 64-bit flags depending on the Endianness, i.e. (__be64)0x0001 on BE and (__be64)0x00010000... on LE, but that would introduce an Endianness dependency and spawn a ton of Sparse warnings. To mitigate them, all of those places which were adjusted with this change would be touched anyway, so why not define stuff properly if there's no choice. Define IP_TUNNEL_*_BIT counterparts as a bit number instead of the value already coded and a fistful of <16 <-> bitmap> converters and helpers. The two flags which have a different bit position are SIT_ISATAP_BIT and VTI_ISVTI_BIT, as they were defined not as __cpu_to_be16(), but as (__force __be16), i.e. had different positions on LE and BE. Now they both have strongly defined places. Change all __be16 fields which were used to store those flags, to IP_TUNNEL_DECLARE_FLAGS() -> DECLARE_BITMAP(__IP_TUNNEL_FLAG_NUM) -> unsigned long[1] for now, and replace all TUNNEL_* occurrences to their bitmap counterparts. Use the converters in the places which talk to the userspace, hardware (NFP) or other hosts (GRE header). The rest must explicitly use the new flags only. This must be done at once, otherwise there will be too many conversions throughout the code in the intermediate commits. Finally, disable the old __be16 flags for use in the kernel code (except for the two 'irregular' flags mentioned above), to prevent any accidental (mis)use of them. For the userspace, nothing is changed, only additions were made. Most noticeable bloat-o-meter difference (.text): vmlinux: 307/-1 (306) gre.ko: 62/0 (62) ip_gre.ko: 941/-217 (724) [*] ip_tunnel.ko: 390/-900 (-510) [**] ip_vti.ko: 138/0 (138) ip6_gre.ko: 534/-18 (516) [*] ip6_tunnel.ko: 118/-10 (108) [*] gre_flags_to_tnl_flags() grew, but still is inlined [**] ip_tunnel_find() got uninlined, hence such decrease The average code size increase in non-extreme case is 100-200 bytes per module, mostly due to sizeof(long) > sizeof(__be16), as %__IP_TUNNEL_FLAG_NUM is less than %BITS_PER_LONG and the compilers are able to expand the majority of bitmap_*() calls here into direct operations on scalars. Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-29erspan: make sure erspan_base_hdr is present in skb->headEric Dumazet
syzbot reported a problem in ip6erspan_rcv() [1] Issue is that ip6erspan_rcv() (and erspan_rcv()) no longer make sure erspan_base_hdr is present in skb linear part (skb->head) before getting @ver field from it. Add the missing pskb_may_pull() calls. v2: Reload iph pointer in erspan_rcv() after pskb_may_pull() because skb->head might have changed. [1] BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2742 [inline] BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2756 [inline] BUG: KMSAN: uninit-value in ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline] BUG: KMSAN: uninit-value in gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610 pskb_may_pull_reason include/linux/skbuff.h:2742 [inline] pskb_may_pull include/linux/skbuff.h:2756 [inline] ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline] gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610 ip6_protocol_deliver_rcu+0x1d4c/0x2ca0 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:460 [inline] ip6_rcv_finish+0x955/0x970 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [inline] ipv6_rcv+0xde/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5652 netif_receive_skb_internal net/core/dev.c:5738 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5798 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549 tun_get_user+0x5566/0x69e0 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb63/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577 __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [inline] alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795 tun_alloc_skb drivers/net/tun.c:1525 [inline] tun_get_user+0x209a/0x69e0 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb63/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 CPU: 1 PID: 5045 Comm: syz-executor114 Not tainted 6.9.0-rc1-syzkaller-00021-g962490525cff #0 Fixes: cb73ee40b1b3 ("net: ip_gre: use erspan key field for tunnel lookup") Reported-by: syzbot+1c1cf138518bf0c53d68@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/000000000000772f2c0614b66ef7@google.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/20240328112248.1101491-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-14Merge tag 'mm-nonmm-stable-2024-03-14-09-36' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min heap optimizations". - Kuan-Wei Chiu has also sped up the library sorting code in the series "lib/sort: Optimize the number of swaps and comparisons". - Alexey Gladkov has added the ability for code running within an IPC namespace to alter its IPC and MQ limits. The series is "Allow to change ipc/mq sysctls inside ipc namespace". - Geert Uytterhoeven has contributed some dhrystone maintenance work in the series "lib: dhry: miscellaneous cleanups". - Ryusuke Konishi continues nilfs2 maintenance work in the series "nilfs2: eliminate kmap and kmap_atomic calls" "nilfs2: fix kernel bug at submit_bh_wbc()" - Nathan Chancellor has updated our build tools requirements in the series "Bump the minimum supported version of LLVM to 13.0.1". - Muhammad Usama Anjum continues with the selftests maintenance work in the series "selftests/mm: Improve run_vmtests.sh". - Oleg Nesterov has done some maintenance work against the signal code in the series "get_signal: minor cleanups and fix". Plus the usual shower of singleton patches in various parts of the tree. Please see the individual changelogs for details. * tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits) nilfs2: prevent kernel bug at submit_bh_wbc() nilfs2: fix failure to detect DAT corruption in btree and direct mappings ocfs2: enable ocfs2_listxattr for special files ocfs2: remove SLAB_MEM_SPREAD flag usage assoc_array: fix the return value in assoc_array_insert_mid_shortcut() buildid: use kmap_local_page() watchdog/core: remove sysctl handlers from public header nilfs2: use div64_ul() instead of do_div() mul_u64_u64_div_u64: increase precision by conditionally swapping a and b kexec: copy only happens before uchunk goes to zero get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig get_signal: don't abuse ksig->info.si_signo and ksig->sig const_structs.checkpatch: add device_type Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>" dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace() list: leverage list_is_head() for list_entry_is_head() nilfs2: MAINTAINERS: drop unreachable project mirror site smp: make __smp_processor_id() 0-argument macro fat: fix uninitialized field in nostale filehandles ...
2024-03-06Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>"Ahelenia Ziemiańska
Found with git grep 'MODULE_AUTHOR(".*([^)]*@' Fixed with sed -i '/MODULE_AUTHOR(".*([^)]*@/{s/ (/ </g;s/)"/>"/;s/)and/> and/}' \ $(git grep -l 'MODULE_AUTHOR(".*([^)]*@') Also: in drivers/media/usb/siano/smsusb.c normalise ", INC" to ", Inc"; this is what every other MODULE_AUTHOR for this company says, and it's what the header says in drivers/sbus/char/openprom.c normalise a double-spaced separator; this is clearly copied from the copyright header, where the names are aligned on consecutive lines thusly: * Linux/SPARC PROM Configuration Driver * Copyright (C) 1996 Thomas K. Dyas (tdyas@noc.rutgers.edu) * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) but the authorship branding is single-line Link: https://lkml.kernel.org/r/mk3geln4azm5binjjlfsgjepow4o73domjv6ajybws3tz22vb3@tarta.nabijaczleweli.xyz Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-13net: add netdev_lockdep_set_classes() to virtual driversEric Dumazet
Based on a syzbot report, it appears many virtual drivers do not yet use netdev_lockdep_set_classes(), triggerring lockdep false positives. WARNING: possible recursive locking detected 6.8.0-rc4-next-20240212-syzkaller #0 Not tainted syz-executor.0/19016 is trying to acquire lock: ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline] ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340 but task is already holding lock: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline] ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340 other info that might help us debug this: Possible unsafe locking scenario: CPU0 lock(_xmit_ETHER#2); lock(_xmit_ETHER#2); *** DEADLOCK *** May be due to missing lock nesting notation 9 locks held by syz-executor.0/19016: #0: ffffffff8f385208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f385208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6603 #1: ffffc90000a08c00 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1697 #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1360 net/ipv4/ip_output.c:228 #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4284 #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:195 [inline] #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3771 [inline] #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3b10 net/core/dev.c:4325 #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline] #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340 #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1360 net/ipv4/ip_output.c:228 #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4284 #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:195 [inline] #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3771 [inline] #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3b10 net/core/dev.c:4325 stack backtrace: CPU: 1 PID: 19016 Comm: syz-executor.0 Not tainted 6.8.0-rc4-next-20240212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __netif_tx_lock include/linux/netdevice.h:4452 [inline] sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3784 [inline] __dev_queue_xmit+0x1912/0x3b10 net/core/dev.c:4325 neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0xe66/0x1360 net/ipv4/ip_output.c:235 iptunnel_xmit+0x540/0x9b0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x20ee/0x2960 net/ipv4/ip_tunnel.c:831 erspan_xmit+0x9de/0x1460 net/ipv4/ip_gre.c:720 __netdev_start_xmit include/linux/netdevice.h:4989 [inline] netdev_start_xmit include/linux/netdevice.h:5003 [inline] xmit_one net/core/dev.c:3555 [inline] dev_hard_start_xmit+0x242/0x770 net/core/dev.c:3571 sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3784 [inline] __dev_queue_xmit+0x1912/0x3b10 net/core/dev.c:4325 neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0xe66/0x1360 net/ipv4/ip_output.c:235 igmpv3_send_cr net/ipv4/igmp.c:723 [inline] igmp_ifc_timer_expire+0xb71/0xd90 net/ipv4/igmp.c:813 call_timer_fn+0x17e/0x600 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x621/0x830 kernel/time/timer.c:2038 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2051 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1076 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1076 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:resched_offsets_ok kernel/sched/core.c:10127 [inline] RIP: 0010:__might_resched+0x16f/0x780 kernel/sched/core.c:10142 Code: 00 4c 89 e8 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 48 89 44 24 38 0f b6 04 10 84 c0 0f 85 87 04 00 00 41 8b 45 00 c1 e0 08 <01> d8 44 39 e0 0f 85 d6 00 00 00 44 89 64 24 1c 48 8d bc 24 a0 00 RSP: 0018:ffffc9000ee069e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880296a9e00 RDX: dffffc0000000000 RSI: ffff8880296a9e00 RDI: ffffffff8bfe8fa0 RBP: ffffc9000ee06b00 R08: ffffffff82326877 R09: 1ffff11002b5ad1b R10: dffffc0000000000 R11: ffffed1002b5ad1c R12: 0000000000000000 R13: ffff8880296aa23c R14: 000000000000062a R15: 1ffff92001dc0d44 down_write+0x19/0x50 kernel/locking/rwsem.c:1578 kernfs_activate fs/kernfs/dir.c:1403 [inline] kernfs_add_one+0x4af/0x8b0 fs/kernfs/dir.c:819 __kernfs_create_file+0x22e/0x2e0 fs/kernfs/file.c:1056 sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:307 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x4f4/0xf20 fs/sysfs/group.c:152 internal_create_groups fs/sysfs/group.c:192 [inline] sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:218 create_dir lib/kobject.c:78 [inline] kobject_add_internal+0x472/0x8d0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x124/0x190 lib/kobject.c:457 netdev_queue_add_kobject net/core/net-sysfs.c:1706 [inline] netdev_queue_update_kobjects+0x1f3/0x480 net/core/net-sysfs.c:1758 register_queue_kobjects net/core/net-sysfs.c:1819 [inline] netdev_register_kobject+0x265/0x310 net/core/net-sysfs.c:2059 register_netdevice+0x1191/0x19c0 net/core/dev.c:10298 bond_newlink+0x3b/0x90 drivers/net/bonding/bond_netlink.c:576 rtnl_newlink_create net/core/rtnetlink.c:3506 [inline] __rtnl_newlink net/core/rtnetlink.c:3726 [inline] rtnl_newlink+0x158f/0x20a0 net/core/rtnetlink.c:3739 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6606 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3c/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2199 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fc3fa87fa9c Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240212140700.2795436-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-07ip6_gre: use exit_batch_rtnl() methodEric Dumazet
exit_batch_rtnl() is called while RTNL is held, and devices to be unregistered can be queued in the dev_kill_list. This saves one rtnl_lock()/rtnl_unlock() pair and one unregister_netdevice_many() call. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Antoine Tenart <atenart@kernel.org> Link: https://lore.kernel.org/r/20240206144313.2050392-11-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-19net:ipv6: check return value of pskb_trim()Yuanjun Gong
goto tx_err if an unexpected result is returned by pskb_tirm() in ip6erspan_tunnel_xmit(). Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support") Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-13erspan: get the proto with the md version for collect_mdXin Long
In commit 20704bd1633d ("erspan: build the header with the right proto according to erspan_ver"), it gets the proto with t->parms.erspan_ver, but t->parms.erspan_ver is not used by collect_md branch, and instead it should get the proto with md->version for collect_md. Thanks to Kevin for pointing this out. Fixes: 20704bd1633d ("erspan: build the header with the right proto according to erspan_ver") Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support") Reported-by: Kevin Traynor <ktraynor@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>