From a01aee7cafc575bb82f5529e8734e7052f9b16ea Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Thu, 26 Mar 2026 03:44:39 +0000 Subject: [PATCH 1/3] bridge: br_nd_send: linearize skb before parsing ND options br_nd_send() parses neighbour discovery options from ns->opt[] and assumes that these options are in the linear part of request. Its callers only guarantee that the ICMPv6 header and target address are available, so the option area can still be non-linear. Parsing ns->opt[] in that case can access data past the linear buffer. Linearize request before option parsing and derive ns from the linear network header. Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports") Reported-by: Yifan Wu Reported-by: Juefei Pu Tested-by: Ao Zhou Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Yang Yang Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260326034441.2037420-2-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski --- net/bridge/br_arp_nd_proxy.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c index 1e2b51769eec..af3d1e33f50b 100644 --- a/net/bridge/br_arp_nd_proxy.c +++ b/net/bridge/br_arp_nd_proxy.c @@ -251,12 +251,12 @@ struct nd_msg *br_is_nd_neigh_msg(const struct sk_buff *skb, struct nd_msg *msg) static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, struct sk_buff *request, struct neighbour *n, - __be16 vlan_proto, u16 vlan_tci, struct nd_msg *ns) + __be16 vlan_proto, u16 vlan_tci) { struct net_device *dev = request->dev; struct net_bridge_vlan_group *vg; + struct nd_msg *na, *ns; struct sk_buff *reply; - struct nd_msg *na; struct ipv6hdr *pip6; int na_olen = 8; /* opt hdr + ETH_ALEN for target */ int ns_olen; @@ -264,7 +264,7 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, u8 *daddr; u16 pvid; - if (!dev) + if (!dev || skb_linearize(request)) return; len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) + @@ -281,6 +281,8 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, skb_set_mac_header(reply, 0); daddr = eth_hdr(request)->h_source; + ns = (struct nd_msg *)(skb_network_header(request) + + sizeof(struct ipv6hdr)); /* Do we need option processing ? */ ns_olen = request->len - (skb_network_offset(request) + @@ -472,9 +474,9 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, if (vid != 0) br_nd_send(br, p, skb, n, skb->vlan_proto, - skb_vlan_tag_get(skb), msg); + skb_vlan_tag_get(skb)); else - br_nd_send(br, p, skb, n, 0, 0, msg); + br_nd_send(br, p, skb, n, 0, 0); replied = true; } From 850837965af15707fd3142c1cf3c5bfaf022299b Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Thu, 26 Mar 2026 03:44:40 +0000 Subject: [PATCH 2/3] bridge: br_nd_send: validate ND option lengths br_nd_send() walks ND options according to option-provided lengths. A malformed option can make the parser advance beyond the computed option span or use a too-short source LLADDR option payload. Validate option lengths against the remaining NS option area before advancing, and only read source LLADDR when the option is large enough for an Ethernet address. Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports") Cc: stable@vger.kernel.org Reported-by: Yifan Wu Reported-by: Juefei Pu Tested-by: Ao Zhou Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Yang Yang Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260326034441.2037420-3-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski --- net/bridge/br_arp_nd_proxy.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c index af3d1e33f50b..6b5595868a39 100644 --- a/net/bridge/br_arp_nd_proxy.c +++ b/net/bridge/br_arp_nd_proxy.c @@ -288,12 +288,14 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, ns_olen = request->len - (skb_network_offset(request) + sizeof(struct ipv6hdr)) - sizeof(*ns); for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) { - if (!ns->opt[i + 1]) { + if (!ns->opt[i + 1] || i + (ns->opt[i + 1] << 3) > ns_olen) { kfree_skb(reply); return; } if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) { - daddr = ns->opt + i + sizeof(struct nd_opt_hdr); + if ((ns->opt[i + 1] << 3) >= + sizeof(struct nd_opt_hdr) + ETH_ALEN) + daddr = ns->opt + i + sizeof(struct nd_opt_hdr); break; } } From afa9a05e6c4971bd5586f1b304e14d61fb3d9385 Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Thu, 26 Mar 2026 03:44:41 +0000 Subject: [PATCH 3/3] vxlan: validate ND option lengths in vxlan_na_create vxlan_na_create() walks ND options according to option-provided lengths. A malformed option can make the parser advance beyond the computed option span or use a too-short source LLADDR option payload. Validate option lengths against the remaining NS option area before advancing, and only read source LLADDR when the option is large enough for an Ethernet address. Fixes: 4b29dba9c085 ("vxlan: fix nonfunctional neigh_reduce()") Cc: stable@vger.kernel.org Reported-by: Yifan Wu Reported-by: Juefei Pu Tested-by: Ao Zhou Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Yang Yang Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260326034441.2037420-4-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski --- drivers/net/vxlan/vxlan_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index 17c941aac32d..a94ac82a6136 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -1965,12 +1965,14 @@ static struct sk_buff *vxlan_na_create(struct sk_buff *request, ns_olen = request->len - skb_network_offset(request) - sizeof(struct ipv6hdr) - sizeof(*ns); for (i = 0; i < ns_olen-1; i += (ns->opt[i+1]<<3)) { - if (!ns->opt[i + 1]) { + if (!ns->opt[i + 1] || i + (ns->opt[i + 1] << 3) > ns_olen) { kfree_skb(reply); return NULL; } if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) { - daddr = ns->opt + i + sizeof(struct nd_opt_hdr); + if ((ns->opt[i + 1] << 3) >= + sizeof(struct nd_opt_hdr) + ETH_ALEN) + daddr = ns->opt + i + sizeof(struct nd_opt_hdr); break; } }