ipv6: raw: Deduct extension header length in rawv6_push_pending_frames

stable inclusion
from stable-v4.19.270
commit f487d636e49bc1fdfbd8105bc1ab159164e2d8bd
category: bugfix
bugzilla: 188291, https://gitee.com/src-openeuler/kernel/issues/I6B1V2
CVE: CVE-2023-0394

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.19.y&id=f487d636e49bc1fdfbd8105bc1ab159164e2d8bd



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commit cb3e9864 upstream.

The total cork length created by ip6_append_data includes extension
headers, so we must exclude them when comparing them against the
IPV6_CHECKSUM offset which does not include extension headers.

Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Fixes: 357b40a1 ("[IPV6]: IPV6_CHECKSUM socket option can corrupt kernel memory")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lu Wei <luwei32@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>