kernel/git/stable/linux.git/drivers/net/vxlan, branch linux-6.1.y

vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes

2026-09-14T11:25:42+00:00

[ Upstream commit 984f831dda31b3a18f47454cf64989f65402879e ] The VXLAN VNI filter entry policy declares the GROUP/GROUP6 address attributes as NLA_BINARY with only a maximum length, so validate_nla() accepts a payload shorter than the address. The GROUP consumer reads it with nla_get_in_addr(), an unconditional 4-byte load, so a short attribute over-reads up to 3 bytes of uninitialised slab data, which are stored into remote_ip and echoed back via RTM_GETTUNNEL, disclosing kernel memory. Switch both entries to NLA_POLICY_EXACT_LEN() so the validator rejects any GROUP/GROUP6 that is not exactly 4 / 16 bytes; a valid address is always sent at full width. Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260812215341.763123-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

vxlan: use pskb_network_may_pull() for transmit path header pulls

2026-09-14T11:24:22+00:00

[ Upstream commit b9553558b48db54ac9273e6b98d7263ef5c1a329 ] In vxlan_xmit(), arp_reduce(), and vxlan_mdb_entry_skb_get(), pskb_may_pull() was being called to verify the availability of network layer headers (ARP, IPv6/ND, IP/IPv6 MDB keys). However, during transmit skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, len) only checks len bytes from skb->data rather than skb_network_offset(skb) + len, which can leave part of the network header in non-linear frags. Replace these remaining pskb_may_pull() calls with pskb_network_may_pull() to properly account for the MAC header offset. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Fixes: f564f45c4518 ("vxlan: add ipv6 proxy support") Fixes: 0f83e69f44bf ("vxlan: Add MDB data path support") Signed-off-by: Eric Dumazet Cc: stable@vger.kernel.org Reviewed-by: Vadim Fedorenko Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260723144249.759100-6-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Miguel Gazquez (Schneider Electric) Signed-off-by: Sasha Levin

vxlan: do not arm the ageing timer on a device that is down

2026-08-19T15:16:28+00:00

commit b37971686ec59fb027fa4910ba16805e68fddb97 upstream. vxlan_changelink() arms vxlan->age_timer whenever the requested ageing interval differs from the configured one: if (conf.age_interval != vxlan->cfg.age_interval) mod_timer(&vxlan->age_timer, jiffies); There is no netif_running() test, so the timer is armed even on a device that was never brought up. The only synchronous cancel in the driver is the timer_delete_sync() in vxlan_stop(), which is .ndo_stop. netif_close_many() drops devices without IFF_UP before __dev_close_many() runs, so that cancel is skipped for such a device. vxlan_setup() sets dev->needs_free_netdev = true and age_timer is a member of struct vxlan_dev, so free_netdev() releases the allocation the timer lives in while it is still queued on a timer_base. expire_timers() unlinks the entry before it loads timer->function, so the timer core writes through the freed object's list pointers: BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654 Write of size 8 at addr ffff00001adace68 by task true/192 __asan_store8+0x84/0xac __run_timers+0x208/0x654 run_timer_softirq+0x154/0x18c Allocated by task 189: alloc_netdev_mqs+0x64/0x720 rtnl_create_link+0x4ac/0x520 rtnl_newlink+0x758/0xd00 Freed by task 191: netdev_release+0x40/0x58 netdev_run_todo+0x4a4/0x8c0 rtnl_dellink+0x200/0x4e8 The rtnl operations involved are netns-scoped, so an unprivileged user can perform them in a new user and network namespace. Arming the timer on a down device never had an effect: vxlan_cleanup() returns early on !netif_running(), and vxlan_open() arms the timer for any non-zero interval once the device is brought up. Add the missing test. Discovered by XBOW, triaged by Baul Lee Fixes: 40051c4dcad5 ("vxlan: Allow changing ageing time") Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260809111829.78834-1-baul.lee@xbow.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

vxlan: use pskb_network_may_pull() in route_shortcircuit()

2026-08-19T15:16:18+00:00

commit 26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb upstream. route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr)) (or ipv6hdr), which checks if bytes are available starting from skb->data. However, in vxlan_xmit(), skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20) only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of IP header), leaving the rest of the IP header potentially un-pulled in non-linear frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled linear buffer length. Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to the length check to ensure the full network header is present in the linear buffer. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet Reviewed-by: Vadim Fedorenko Link: https://patch.msgid.link/20260723144249.759100-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

vxlan: use neigh_ha_snapshot() in route_shortcircuit()

2026-08-19T15:16:18+00:00

commit 8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d upstream. The neighbour hardware address n->ha can be updated asynchronously by the neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without holding the seqlock loop can lead to torn reads or reading a partially updated MAC address. Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under read_seqbegin()/read_seqretry() lock protection before using it. Note that arp_reduce() and neigh_reduce() seem to have the same issue left for future patches. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet Reviewed-by: Vadim Fedorenko Link: https://patch.msgid.link/20260723144249.759100-4-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

vxlan: unclone skb head before modifying eth header in route_shortcircuit()

2026-08-19T15:16:18+00:00

commit 760d36e737f2b3867762f42af36c663f55babcc4 upstream. When route_shortcircuit() performs L3 short-circuit routing, it modifies the Ethernet header of the skb in-place: memcpy(eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, dev->addr_len); memcpy(eth_hdr(skb)->h_dest, n->ha, dev->addr_len); If the incoming skb is cloned (for example by packet sockets, tcpdump, or dev_queue_xmit), modifying the Ethernet header without uncloning can corrupt the packet header for other readers holding a reference to the cloned skb. Ensure the skb header is writable and unshared by calling skb_cow_head(skb, 0) prior to updating the Ethernet header. If skb_cow_head() fails, abort short-circuiting and return false to allow standard packet processing fallback. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260723144249.759100-3-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

vxlan: re-fetch eth header after route_shortcircuit()

2026-08-19T15:16:18+00:00

commit 1395a676ec15a0a02a2a6d86602324f2d5fd41d5 upstream. Before route_shortcircuit(), the eth header pointer is cached from eth_hdr(skb). Inside route_shortcircuit(), pskb_may_pull() can be called, which may reallocate skb->head. In this case, returning to vxlan_xmit() leaves the cached eth pointer pointing to freed memory, leading to a use-after-free when dereferencing eth->h_dest. Fix this by updating eth = eth_hdr(skb) after calling route_shortcircuit(). Fixes: ae8840825605 ("VXLAN: Allow L2 redirection with L3 switching") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet Reviewed-by: Vadim Fedorenko Link: https://patch.msgid.link/20260723144249.759100-2-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ipv6: introduce dst_rt6_info() helper

2026-08-19T15:16:12+00:00

[ Upstream commit e8dfd42c17faf183415323db1ef0c977be0d6489 ] Instead of (struct rt6_info *)dst casts, we can use : #define dst_rt6_info(_ptr) \ container_of_const(_ptr, struct rt6_info, dst) Some places needed missing const qualifiers : ip6_confirm_neigh(), ipv6_anycast_destination(), ipv6_unicast_destination(), has_gateway() v2: added missing parts (David Ahern) Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller Stable-dep-of: e876b75b9020 ("ipvs: fix the checksum validations") Signed-off-by: Sasha Levin

vxlan: require CAP_NET_ADMIN in the device netns for changelink

2026-08-19T15:16:08+00:00

commit 3a61bd9637f3d929aa846e4eb3d98b48c26fcb0e upstream. A tunnel changelink() operates on at most two netns, dev_net(dev) and the sticky underlay netns vxlan->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 vxlan->net can rewrite a vxlan device whose underlay lives in vxlan->net. vxlan_changelink() validates and applies the new configuration against vxlan->net (vxlan_config_validate(vxlan->net, ...)) and can reopen the underlay socket in that netns, so the same reasoning as the tunnel changelink series applies here. Gate vxlan_changelink() with rtnl_dev_link_net_capable(), at the top of the op before any attribute is parsed, matching ipgre_changelink() and the rest of the "require CAP_NET_ADMIN in the device netns for changelink" series. Found by 0sec automated security-research tooling (https://0sec.ai). Fixes: 8bcdc4f3a20b ("vxlan: add changelink support") Cc: stable@vger.kernel.org Signed-off-by: Doruk Tan Ozturk Reviewed-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260716203500.70573-2-doruk@0sec.ai Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().

2026-07-24T13:54:33+00:00

[ Upstream commit 30a45c0bffdd62350261e2f2689fdba426a33578 ] udp_tunnel_sock_release() could set sk->sk_user_data to NULL while vxlan_gro_prepare_receive() is running. Let's check if rcu_dereference_sk_user_data() is NULL after skb_gro_remcsum_init(). Fixes: 5602c48cf875 ("vxlan: change vxlan to use UDP socket GRO") Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260502031401.3557229-7-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin