5.15-stable review patch. If anyone has any objections, please let me know.
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From: Guillaume Nault gnault@redhat.com
[ Upstream commit fc486c2d060f67d672ddad81724f7c8a4d329570 ]
This reverts commit 183185a18ff96751db52a46ccf93fff3a1f42815.
This patch broke net/forwarding/ip6gre_custom_multipath_hash.sh in some circumstances (https://lore.kernel.org/netdev/Z9RIyKZDNoka53EO@mini-arch/). Let's revert it while the problem is being investigated.
Fixes: 183185a18ff9 ("gre: Fix IPv6 link-local address generation.") Signed-off-by: Guillaume Nault gnault@redhat.com Link: https://patch.msgid.link/8b1ce738eb15dd841aab9ef888640cab4f6ccfea.1742418408... Acked-by: Stanislav Fomichev sdf@fomichev.me Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/addrconf.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f5cca40b71610..932a10f64adcb 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3145,13 +3145,16 @@ static void add_v4_addrs(struct inet6_dev *idev) struct in6_addr addr; struct net_device *dev; struct net *net = dev_net(idev->dev); - int scope, plen; + int scope, plen, offset = 0; u32 pflags = 0;
ASSERT_RTNL();
memset(&addr, 0, sizeof(struct in6_addr)); - memcpy(&addr.s6_addr32[3], idev->dev->dev_addr, 4); + /* in case of IP6GRE the dev_addr is an IPv6 and therefore we use only the last 4 bytes */ + if (idev->dev->addr_len == sizeof(struct in6_addr)) + offset = sizeof(struct in6_addr) - 4; + memcpy(&addr.s6_addr32[3], idev->dev->dev_addr + offset, 4);
if (!(idev->dev->flags & IFF_POINTOPOINT) && idev->dev->type == ARPHRD_SIT) { scope = IPV6_ADDR_COMPATv4; @@ -3459,13 +3462,7 @@ static void addrconf_gre_config(struct net_device *dev) return; }
- /* Generate the IPv6 link-local address using addrconf_addr_gen(), - * unless we have an IPv4 GRE device not bound to an IP address and - * which is in EUI64 mode (as __ipv6_isatap_ifid() would fail in this - * case). Such devices fall back to add_v4_addrs() instead. - */ - if (!(dev->type == ARPHRD_IPGRE && *(__be32 *)dev->dev_addr == 0 && - idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)) { + if (dev->type == ARPHRD_ETHER) { addrconf_addr_gen(idev, true); return; }