From: Yajun Deng yajun.deng@linux.dev
stable inclusion from stable-v5.10.96 commit 9b4444197252bec2f3248b3e4fff11a5d571c19e bugzilla: https://gitee.com/openeuler/kernel/issues/I55NWB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 1b9fbe813016b08e08b22ddba4ddbf9cb1b04b00 ]
Add a if statements to avoid the warning.
Dan Carpenter report: The patch faf482ca196a: "net: ipv4: Move ip_options_fragment() out of loop" from Aug 23, 2021, leads to the following Smatch complaint:
net/ipv4/ip_output.c:833 ip_do_fragment() warn: variable dereferenced before check 'iter.frag' (see line 828)
Reported-by: Dan Carpenter dan.carpenter@oracle.com Fixes: faf482ca196a ("net: ipv4: Move ip_options_fragment() out of loop") Link: https://lore.kernel.org/netdev/20210830073802.GR7722@kadam/T/#t Signed-off-by: Yajun Deng yajun.deng@linux.dev Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- net/ipv4/ip_output.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index fb91a466b2d3..e77afaecc981 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -833,7 +833,9 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
/* Everything is OK. Generate! */ ip_fraglist_init(skb, iph, hlen, &iter); - ip_options_fragment(iter.frag); + + if (iter.frag) + ip_options_fragment(iter.frag);
for (;;) { /* Prepare header of the next frame,