This is a note to let you know that I've just added the patch titled net: ipv6: fix return value of ip6_skb_dst_mtu to the 5.13-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: net-ipv6-fix-return-value-of-ip6_skb_dst_mtu.patch and it can be found in the queue-5.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 40fc3054b45820c28ea3c65e2c86d041dc244a8a Mon Sep 17 00:00:00 2001 From: Vadim Fedorenko <vfedorenko@xxxxxxxx> Date: Fri, 2 Jul 2021 02:47:00 +0300 Subject: net: ipv6: fix return value of ip6_skb_dst_mtu From: Vadim Fedorenko <vfedorenko@xxxxxxxx> commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream. Commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced ip6_skb_dst_mtu with return value of signed int which is inconsistent with actually returned values. Also 2 users of this function actually assign its value to unsigned int variable and only __xfrm6_output assigns result of this function to signed variable but actually uses as unsigned in further comparisons and calls. Change this function to return unsigned int value. Fixes: 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> Signed-off-by: Vadim Fedorenko <vfedorenko@xxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/ip6_route.h | 2 +- net/ipv6/xfrm6_output.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -263,7 +263,7 @@ static inline bool ipv6_anycast_destinat int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)); -static inline int ip6_skb_dst_mtu(struct sk_buff *skb) +static inline unsigned int ip6_skb_dst_mtu(struct sk_buff *skb) { int mtu; --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -56,7 +56,7 @@ static int __xfrm6_output(struct net *ne { struct dst_entry *dst = skb_dst(skb); struct xfrm_state *x = dst->xfrm; - int mtu; + unsigned int mtu; bool toobig; #ifdef CONFIG_NETFILTER Patches currently in stable-queue which might be from vfedorenko@xxxxxxxx are queue-5.13/net-ipv6-fix-return-value-of-ip6_skb_dst_mtu.patch