This is a note to let you know that I've just added the patch titled ipv6: Fix potential uninit-value access in __ip6_make_skb() to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-fix-potential-uninit-value-access-in-__ip6_make.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b803daae2bc4a6b7207c65307eb347dd2c33b7a6 Author: Shigeru Yoshida <syoshida@xxxxxxxxxx> Date: Mon May 6 23:11:29 2024 +0900 ipv6: Fix potential uninit-value access in __ip6_make_skb() [ Upstream commit 4e13d3a9c25b7080f8a619f961e943fe08c2672c ] As it was done in commit fc1092f51567 ("ipv4: Fix uninit-value access in __ip_make_skb()") for IPv4, check FLOWI_FLAG_KNOWN_NH on fl6->flowi6_flags instead of testing HDRINCL on the socket to avoid a race condition which causes uninit-value access. Fixes: ea30388baebc ("ipv6: Fix an uninit variable access bug in __ip6_make_skb()") Signed-off-by: Shigeru Yoshida <syoshida@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 53fe1375b147c..fba789cbd215c 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -2003,7 +2003,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk, u8 icmp6_type; if (sk->sk_socket->type == SOCK_RAW && - !inet_test_bit(HDRINCL, sk)) + !(fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH)) icmp6_type = fl6->fl6_icmp_type; else icmp6_type = icmp6_hdr(skb)->icmp6_type;