[PATCH net-next 03/15] batman-adv: dat: avoid unaligned fault in IP extraction
From: Simon Wunderlich <sw@simonwunderlich.de>
Date: 2026-07-28 13:41:36
Also in:
batman, stable
Subsystem:
batman advanced, the rest · Maintainers:
Marek Lindner, Simon Wunderlich, Antonio Quartulli, Sven Eckelmann, Linus Torvalds
From: Sven Eckelmann <sven@narfation.org>
Independent of the alignment of the ARP packet in the SKB, either the
batadv_arp_ip_src or the batadv_arp_ip_dst will have an unaligned access
(on HW without native unaligned read support).
Use get_unaligned() to handle this properly on all architectures.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: 5c3a0e553593 ("batman-adv: Distributed ARP Table - add ARP parsing functions")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
net/batman-adv/distributed-arp-table.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index a6fe4820f65b9..6ca946da92758 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c@@ -250,7 +250,10 @@ static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) */ static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) { - return *(__force __be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); + u8 *src = batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN; + __be32 *ip = (__force __be32 *)src; + + return get_unaligned(ip); } /**
@@ -275,8 +278,9 @@ static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) { u8 *dst = batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4; + __be32 *ip = (__force __be32 *)dst; - return *(__force __be32 *)dst; + return get_unaligned(ip); } /**
--
2.47.3