On 6/6/23 15:46, Guillaume Nault wrote:
On Tue, Jun 06, 2023 at 08:24:54AM +0200, Mirsad Goran Todorovac wrote:
On 5/31/23 20:11, Guillaume Nault wrote:
I believe this condition should be relaxed to allow the case where ->sk_bound_dev_if is oif's master device (and maybe there are other VRF cases to also consider).
I've tried something like this, but something makes the kernel stuck here:
TEST: ping out, blocked by route - ns-B loopback IPv6 [ OK ] TEST: ping out, device bind, blocked by route - ns-B loopback IPv6 [ OK ] TEST: ping in, blocked by route - ns-A loopback IPv6 [ OK ] TEST: ping out, unreachable route - ns-B loopback IPv6 [ OK ] TEST: ping out, device bind, unreachable route - ns-B loopback IPv6 [ OK ]
################################################################# With VRF
[hanged process and kernel won't shutdown]
The code is:
net/ipv6/ping.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index c4835dbdfcff..81293e902293 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -73,6 +73,9 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) struct rt6_info *rt; struct pingfakehdr pfh; struct ipcm6_cookie ipc6;
struct net *net = sock_net(sk);struct net_device *dev = NULL;struct net_device *mdev = NULL; err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph, sizeof(user_icmph));@@ -111,10 +114,17 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) else if (!oif) oif = np->ucast_oif;
if (oif) {dev = dev_get_by_index(net, oif);mdev = netdev_master_upper_dev_get(dev);}addr_type = ipv6_addr_type(daddr); if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) || (addr_type & IPV6_ADDR_MAPPED) ||
(oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
(oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if &&!(mdev && sk->sk_bound_dev_if &&mdev != dev_get_by_index(net, sk->sk_bound_dev_if)))) return -EINVAL; ipcm6_init_sk(&ipc6, np);I am obviously doing something very stupid.
The problem is that dev_get_by_index() holds a reference on 'dev' which your code never releases. Also netdev_master_upper_dev_get() needs rtnl protection. These should have generated some kernel oops.
You can try this instead:
-------- >8 --------
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index c4835dbdfcff..f804c11e2146 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -114,7 +114,8 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) addr_type = ipv6_addr_type(daddr); if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) || (addr_type & IPV6_ADDR_MAPPED) ||
(oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
(oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if &&l3mdev_master_ifindex_by_index(sock_net(sk), oif) != sk->sk_bound_dev_if))ipcm6_init_sk(&ipc6, np);
The problem appears to be fixed:
# ./fcnal-test.sh [...] TEST: ping out, vrf device+address bind - ns-B loopback IPv6 [ OK ] TEST: ping out, vrf device+address bind - ns-B IPv6 LLA [ OK ] TEST: ping in - ns-A IPv6 [ OK ] [...] Tests passed: 888 Tests failed: 0 #
The test passed in both environments that manifested the bug.
Tested-by: Mirsad Todorovac mirsad.todorovac@alu.unizg.hr
However, test on my AMD Ubuntu 22.04 box with 6.4-rc5 commit a4d7d7011219 has shown additional four failed tests:
root@host # grep -n FAIL ../fcnal-test-4.log 90:TEST: ping local, VRF bind - VRF IP [FAIL] 92:TEST: ping local, device bind - ns-A IP [FAIL] 116:TEST: ping local, VRF bind - VRF IP [FAIL] 118:TEST: ping local, device bind - ns-A IP [FAIL] root@host #
But you would probably want me to file a separate bug report?
Best regards, Mirsad