On 26/03/2026 05:44, Yang Yang wrote:
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: [email protected] Reported-by: Yifan Wu <[email protected]> Reported-by: Juefei Pu <[email protected]> Tested-by: Ao Zhou <[email protected]> Co-developed-by: Yuan Tan <[email protected]> Signed-off-by: Yuan Tan <[email protected]> Suggested-by: Xin Liu <[email protected]> Signed-off-by: Yang Yang <[email protected]> --- 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 17c941aac32db..a94ac82a61364 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; } }
Acked-by: Nikolay Aleksandrov <[email protected]>
