This is a note to let you know that I've just added the patch titled tipc: check the bearer min mtu properly when setting it by netlink to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tipc-check-the-bearer-min-mtu-properly-when-setting-.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 38faf4c273062ef6ce8902a0ab5227cfbe56228c Author: Xin Long <lucien.xin@xxxxxxxxx> Date: Sun May 14 15:52:29 2023 -0400 tipc: check the bearer min mtu properly when setting it by netlink [ Upstream commit 35a089b5d793d2bfd2cc7cfa6104545184de2ce7 ] Checking the bearer min mtu with tipc_udp_mtu_bad() only works for IPv4 UDP bearer, and IPv6 UDP bearer has a different value for the min mtu. This patch checks with encap_hlen + TIPC_MIN_BEARER_MTU for min mtu, which works for both IPv4 and IPv6 UDP bearer. Note that tipc_udp_mtu_bad() is still used to check media min mtu in __tipc_nl_media_set(), as m->mtu currently is only used by the IPv4 UDP bearer as its default mtu value. Fixes: 682cd3cf946b ("tipc: confgiure and apply UDP bearer MTU on running links") Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Acked-by: Jon Maloy <jmaloy@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 0e9a29e1536b7..53881406e2006 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -1151,8 +1151,8 @@ int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info) return -EINVAL; } #ifdef CONFIG_TIPC_MEDIA_UDP - if (tipc_udp_mtu_bad(nla_get_u32 - (props[TIPC_NLA_PROP_MTU]))) { + if (nla_get_u32(props[TIPC_NLA_PROP_MTU]) < + b->encap_hlen + TIPC_MIN_BEARER_MTU) { NL_SET_ERR_MSG(info->extack, "MTU value is out-of-range"); return -EINVAL;