Re: [syzbot] [PATCH net] netlink: Fix kernel-infoleak in __skb_datagram_iter()

From: syzbot
Date: Tue Feb 20 2024 - 07:01:02 EST


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Subject: [PATCH net] netlink: Fix kernel-infoleak in __skb_datagram_iter()
Author: ryasuoka@xxxxxxxxxx

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5bd7ef53ffe5ca580e93e74eb8c81ed191ddc4bd

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index eb086b06d60d..8277399d19b3 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -167,7 +167,7 @@ static inline u32 netlink_group_mask(u32 group)
static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
gfp_t gfp_mask)
{
- unsigned int len = skb_end_offset(skb);
+ unsigned int len = skb->len;
struct sk_buff *new;

new = alloc_skb(len, gfp_mask);