From c04f7dfe6ec2a3a20a8578d5f67a436ae36e2a2a Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Thu, 21 Mar 2024 19:30:42 +0200 Subject: [PATCH] ipv6: Fix address dump when IPv6 is disabled on an interface Cited commit started returning an error when user space requests to dump the interface's IPv6 addresses and IPv6 is disabled on the interface. Restore the previous behavior and do not return an error. Before cited commit: # ip address show dev dummy1 2: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 1a:52:02:5a:c2:6e brd ff:ff:ff:ff:ff:ff inet6 fe80::1852:2ff:fe5a:c26e/64 scope link proto kernel_ll valid_lft forever preferred_lft forever # ip link set dev dummy1 mtu 1000 # ip address show dev dummy1 2: dummy1: mtu 1000 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 1a:52:02:5a:c2:6e brd ff:ff:ff:ff:ff:ff After cited commit: # ip address show dev dummy1 2: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 1e:9b:94:00:ac:e8 brd ff:ff:ff:ff:ff:ff inet6 fe80::1c9b:94ff:fe00:ace8/64 scope link proto kernel_ll valid_lft forever preferred_lft forever # ip link set dev dummy1 mtu 1000 # ip address show dev dummy1 RTNETLINK answers: No such device Dump terminated With this patch: # ip address show dev dummy1 2: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 42:35:fc:53:66:cf brd ff:ff:ff:ff:ff:ff inet6 fe80::4035:fcff:fe53:66cf/64 scope link proto kernel_ll valid_lft forever preferred_lft forever # ip link set dev dummy1 mtu 1000 # ip address show dev dummy1 2: dummy1: mtu 1000 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 42:35:fc:53:66:cf brd ff:ff:ff:ff:ff:ff Fixes: 9cc4cc329d30 ("ipv6: use xa_array iterator to implement inet6_dump_addr()") Reported-by: Gal Pressman Closes: https://lore.kernel.org/netdev/7e261328-42eb-411d-b1b4-ad884eeaae4d@linux.dev/ Tested-by: Gal Pressman Signed-off-by: Ido Schimmel Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240321173042.2151756-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski --- net/ipv6/addrconf.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 247bd4d8ee45a..92db9b474f2bd 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5416,10 +5416,11 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, err = 0; if (fillargs.ifindex) { - err = -ENODEV; dev = dev_get_by_index_rcu(tgt_net, fillargs.ifindex); - if (!dev) + if (!dev) { + err = -ENODEV; goto done; + } idev = __in6_dev_get(dev); if (idev) err = in6_dump_addrs(idev, skb, cb, -- 2.30.2