[PATCH AUTOSEL 6.6 257/294] ipv4: ip_gre: Fix set but not used warning in ipgre_err() if IPv4-only
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REVIEWED: 1 (1M)
From: Sasha Levin <sashal@kernel.org>
Date: 2025-05-05 23:05:18
Also in:
lkml, stable
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
1 review trailer (1 from subsystem maintainers).
From: Geert Uytterhoeven <geert@linux-m68k.org>
[ Upstream commit 50f37fc2a39c4a8cc4813629b4cf239b71c6097d ]
if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled:
net/ipv4/ip_gre.c: In function ‘ipgre_err’:
net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable]
144 | unsigned int data_len = 0;
| ^~~~~~~~
Fix this by moving all data_len processing inside the IPV6-only section
that uses its result.
Reported-by: kernel test robot <redacted>
Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/ (local)
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/d09113cfe2bfaca02f3dddf832fb5f48dd20958b.1738704881.git.geert@linux-m68k.org (local)
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/ip_gre.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 890c15510b421..f261e29adc7c2 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c@@ -140,7 +140,6 @@ static int ipgre_err(struct sk_buff *skb, u32 info, const struct iphdr *iph; const int type = icmp_hdr(skb)->type; const int code = icmp_hdr(skb)->code; - unsigned int data_len = 0; struct ip_tunnel *t; if (tpi->proto == htons(ETH_P_TEB))
@@ -181,7 +180,6 @@ static int ipgre_err(struct sk_buff *skb, u32 info, case ICMP_TIME_EXCEEDED: if (code != ICMP_EXC_TTL) return 0; - data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ break; case ICMP_REDIRECT:
@@ -189,10 +187,16 @@ static int ipgre_err(struct sk_buff *skb, u32 info, } #if IS_ENABLED(CONFIG_IPV6) - if (tpi->proto == htons(ETH_P_IPV6) && - !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, - type, data_len)) - return 0; + if (tpi->proto == htons(ETH_P_IPV6)) { + unsigned int data_len = 0; + + if (type == ICMP_TIME_EXCEEDED) + data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ + + if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, + type, data_len)) + return 0; + } #endif if (t->parms.iph.daddr == 0 ||
--
2.39.5