[REGRESSION J/bisected][PATCH 0/1] Fix Upstream stable v5.15.199

[Yufeng Gao]

On Tue, Mar 10, 2026 at 11:16:43PM +0100, Stefan Bader wrote:
> == Justification ==
> 
> Impact:
> The upstream stable v5.15.199 update included a change to
> __ip6_tnl_rcv() which does not work for kernels <v6.13 (this might be
> important if the following is ever picked):
> 
> 134d7f22da48 "ip6_tunnel: use skb_vlan_inet_prepare() in __ip6_tnl_rcv()"
> 
> Above patch replaces pskb_inet_may_pull() with skb_vlan_inet_prepare().
> The problem is that around v6.13 there was
> 
> "net: tunnel: make skb_vlan_inet_prepare() return drop reasons"
> 
> which changes return values of skb_vlan_inet_prepare(). Before a non
> zero return code meant success while after it is the opposite.
> 
> Fix:
> Instead of pulling another dependency the proposed fix changes usage to
> other callers of skb_vlan_inet_prepare() in v5.15 (bareudp.c/geneve.c).
> 
> Testcase:
> Running the gre_gso.sh selftest with fail (timeout) without the fix.
> After applying the test passes again.
> 
> 
> Stefan Bader (1):
>   UBUNTU: SAUCE: Fix skb_vlan_inet_prepare() usage
> 
>  net/ipv6/ip6_tunnel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Acked-by: Yufeng Gao <yufeng.gao at canonical.com>