On 4/8/22 07:03, Nicolas Dichtel wrote:
kongweibin reported a kernel panic in ip6_forward() when input interface has no in6 dev associated. The following tc commands were used to reproduce this panic: tc qdisc del dev vxlan100 root tc qdisc add dev vxlan100 root netem corrupt 5%
Not sure I understand how these qdisc changes can trigger a NULL idev ? Do we have another bug, like skb->cb[] content being mangled ?
CC: stable@xxxxxxxxxxxxxxx Fixes: ccd27f05ae7b ("ipv6: fix 'disable_policy' for fwd packets") Reported-by: kongweibin <kongweibin2@xxxxxxxxxx> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> --- kongweibin, could you test this patch with your setup? Thanks, Nicolas net/ipv6/ip6_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index e23f058166af..fa63ef2bd99c 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -485,7 +485,7 @@ int ip6_forward(struct sk_buff *skb) goto drop;if (!net->ipv6.devconf_all->disable_policy &&- !idev->cnf.disable_policy && + (!idev || !idev->cnf.disable_policy) && !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); goto drop;
