linux-kernel - [PATCH net-next v2 1/2] xsk: respect the offsets when copying frags

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20250426081220.40689-2-minhquangbui99@gmail.com>
Date: Sat, 26 Apr 2025 15:12:19 +0700
From: Bui Quang Minh <minhquangbui99@...il.com>
To: netdev@...r.kernel.org
Cc: Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	"David S. Miller" <davem@...emloft.net>,
	Jakub Kicinski <kuba@...nel.org>,
	Jesper Dangaard Brouer <hawk@...nel.org>,
	John Fastabend <john.fastabend@...il.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Maciej Fijalkowski <maciej.fijalkowski@...el.com>,
	Alexander Lobakin <aleksander.lobakin@...el.com>,
	bpf@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Bui Quang Minh <minhquangbui99@...il.com>
Subject: [PATCH net-next v2 1/2] xsk: respect the offsets when copying frags

In commit 560d958c6c68 ("xsk: add generic XSk &xdp_buff -> skb
conversion"), we introduce a helper to convert zerocopy xdp_buff to skb.
However, in the frag copy, we mistakenly ignore the frag's offset. This
commit adds the missing offset when copying frags in
xdp_copy_frags_from_zc(). This function is not used anywhere so no
backport is needed.

Signed-off-by: Bui Quang Minh <minhquangbui99@...il.com>
---
 net/core/xdp.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/core/xdp.c b/net/core/xdp.c
index ea819764ae39..89111c68e545 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -698,7 +698,8 @@ static noinline bool xdp_copy_frags_from_zc(struct sk_buff *skb,
 	nr_frags = xinfo->nr_frags;
 
 	for (u32 i = 0; i < nr_frags; i++) {
-		u32 len = skb_frag_size(&xinfo->frags[i]);
+		const skb_frag_t *frag = &xinfo->frags[i];
+		u32 len = skb_frag_size(frag);
 		u32 offset, truesize = len;
 		netmem_ref netmem;
 
@@ -708,8 +709,8 @@ static noinline bool xdp_copy_frags_from_zc(struct sk_buff *skb,
 			return false;
 		}
 
-		memcpy(__netmem_address(netmem),
-		       __netmem_address(xinfo->frags[i].netmem),
+		memcpy(__netmem_address(netmem) + offset,
+		       __netmem_address(frag->netmem) + skb_frag_off(frag),
 		       LARGEST_ALIGN(len));
 		__skb_fill_netmem_desc_noacc(sinfo, i, netmem, offset, len);
 
-- 
2.43.0