From 2127c604383666675789fd4a5fc2aead46c73aad Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Fri, 2 Feb 2024 17:32:20 +0100 Subject: xsk: Add truesize to skb_add_rx_frag(). xsk_build_skb() allocates a page and adds it to the skb via skb_add_rx_frag() and specifies 0 for truesize. This leads to a warning in skb_add_rx_frag() with CONFIG_DEBUG_NET enabled because size is larger than truesize. Increasing truesize requires to add the same amount to socket's sk_wmem_alloc counter in order not to underflow the counter during release in the destructor (sock_wfree()). Pass the size of the allocated page as truesize to skb_add_rx_frag(). Add this mount to socket's sk_wmem_alloc counter. Fixes: cf24f5a5feea ("xsk: add support for AF_XDP multi-buffer on Tx path") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Daniel Borkmann Acked-by: Maciej Fijalkowski Link: https://lore.kernel.org/bpf/20240202163221.2488589-1-bigeasy@linutronix.de --- net/xdp/xsk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 1eadfac03cc4..b78c0e095e22 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -722,7 +722,8 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, memcpy(vaddr, buffer, len); kunmap_local(vaddr); - skb_add_rx_frag(skb, nr_frags, page, 0, len, 0); + skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE); + refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc); } if (first_frag && desc->options & XDP_TX_METADATA) { -- cgit From 4cd12c6065dfcdeba10f49949bffcf383b3952d8 Mon Sep 17 00:00:00 2001 From: Shigeru Yoshida Date: Mon, 19 Feb 2024 00:09:33 +0900 Subject: bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready() syzbot reported the following NULL pointer dereference issue [1]: BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] RIP: 0010:0x0 [...] Call Trace: sk_psock_verdict_data_ready+0x232/0x340 net/core/skmsg.c:1230 unix_stream_sendmsg+0x9b4/0x1230 net/unix/af_unix.c:2293 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 If sk_psock_verdict_data_ready() and sk_psock_stop_verdict() are called concurrently, psock->saved_data_ready can be NULL, causing the above issue. This patch fixes this issue by calling the appropriate data ready function using the sk_psock_data_ready() helper and protecting it from concurrency with sk->sk_callback_lock. Fixes: 6df7f764cd3c ("bpf, sockmap: Wake up polling after data copy") Reported-by: syzbot+fd7b34375c1c8ce29c93@syzkaller.appspotmail.com Signed-off-by: Shigeru Yoshida Signed-off-by: Daniel Borkmann Tested-by: syzbot+fd7b34375c1c8ce29c93@syzkaller.appspotmail.com Acked-by: John Fastabend Closes: https://syzkaller.appspot.com/bug?extid=fd7b34375c1c8ce29c93 [1] Link: https://lore.kernel.org/bpf/20240218150933.6004-1-syoshida@redhat.com --- net/core/skmsg.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 93ecfceac1bc..4d75ef9d24bf 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -1226,8 +1226,11 @@ static void sk_psock_verdict_data_ready(struct sock *sk) rcu_read_lock(); psock = sk_psock(sk); - if (psock) - psock->saved_data_ready(sk); + if (psock) { + read_lock_bh(&sk->sk_callback_lock); + sk_psock_data_ready(sk, psock); + read_unlock_bh(&sk->sk_callback_lock); + } rcu_read_unlock(); } } -- cgit