From: Shigeru Yoshida syoshida@redhat.com

mainline inclusion from mainline-v6.9-rc7 commit 4e13d3a9c25b7080f8a619f961e943fe08c2672c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9UAZH CVE: CVE-2024-36903

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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@redhat.com Signed-off-by: David S. Miller davem@davemloft.net

Conflicts: net/ipv6/ip6_output.c [The conflict occurs because commit cafbe182a467("inet: move inet->hdrincl to inet->inet_flags") is not merged] Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com --- net/ipv6/ip6_output.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 9951ccfb3147..968b2602c400 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1738,7 +1738,8 @@ struct sk_buff *__ip6_make_skb(struct sock *sk, struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); u8 icmp6_type;

- if (sk->sk_socket->type == SOCK_RAW && !inet_sk(sk)->hdrincl) + if (sk->sk_socket->type == SOCK_RAW && + !(fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH)) icmp6_type = fl6->fl6_icmp_type; else icmp6_type = icmp6_hdr(skb)->icmp6_type;