linux-kernel - [PATCH net-next] net: add missing check for TCP fraglist GRO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Tue,  7 May 2024 11:41:13 +0200
From: Felix Fietkau <nbd@....name>
To: netdev@...r.kernel.org,
	Eric Dumazet <edumazet@...gle.com>,
	"David S. Miller" <davem@...emloft.net>,
	David Ahern <dsahern@...nel.org>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Willem de Bruijn <willemb@...gle.com>
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH net-next] net: add missing check for TCP fraglist GRO

It turns out that the existing checks do not guarantee that the skb can be
pulled up to the GRO offset. When using the usb r8152 network driver with
GRO fraglist, the BUG() in __skb_pull is often triggered.
Fix the crash by adding the missing check.

Fixes: 8d95dc474f85 ("net: add code for TCP fraglist GRO")
Signed-off-by: Felix Fietkau <nbd@....name>
---
 net/ipv4/tcp_offload.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index c90704befd7b..a71d2e623f0c 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -353,6 +353,7 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb,
 		flush |= (__force int)(flags ^ tcp_flag_word(th2));
 		flush |= skb->ip_summed != p->ip_summed;
 		flush |= skb->csum_level != p->csum_level;
+		flush |= !pskb_may_pull(skb, skb_gro_offset(skb));
 		flush |= NAPI_GRO_CB(p)->count >= 64;
 
 		if (flush || skb_gro_receive_list(p, skb))
-- 
2.44.0