BPF Archive on lore.kernel.org
 help / color / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Ilya Maximets" <i.maximets@samsung.com>,
	"Björn Töpel" <bjorn.topel@intel.com>,
	"William Tu" <u9012063@gmail.com>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Sasha Levin" <sashal@kernel.org>,
	netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 461/671] xdp: fix possible cq entry leak
Date: Thu, 16 Jan 2020 12:01:39 -0500
Message-ID: <20200116170509.12787-198-sashal@kernel.org> (raw)
In-Reply-To: <20200116170509.12787-1-sashal@kernel.org>

From: Ilya Maximets <i.maximets@samsung.com>

[ Upstream commit 675716400da6f15b9d3db04ef74ee74ca9a00af3 ]

Completion queue address reservation could not be undone.
In case of bad 'queue_id' or skb allocation failure, reserved entry
will be leaked reducing the total capacity of completion queue.

Fix that by moving reservation to the point where failure is not
possible. Additionally, 'queue_id' checking moved out from the loop
since there is no point to check it there.

Fixes: 35fcde7f8deb ("xsk: support for Tx")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: William Tu <u9012063@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/xdp/xsk.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 547fc4554b22..c90854bc3048 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -218,6 +218,9 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
 
 	mutex_lock(&xs->mutex);
 
+	if (xs->queue_id >= xs->dev->real_num_tx_queues)
+		goto out;
+
 	while (xskq_peek_desc(xs->tx, &desc)) {
 		char *buffer;
 		u64 addr;
@@ -228,12 +231,6 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
 			goto out;
 		}
 
-		if (xskq_reserve_addr(xs->umem->cq))
-			goto out;
-
-		if (xs->queue_id >= xs->dev->real_num_tx_queues)
-			goto out;
-
 		len = desc.len;
 		skb = sock_alloc_send_skb(sk, len, 1, &err);
 		if (unlikely(!skb)) {
@@ -245,7 +242,7 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
 		addr = desc.addr;
 		buffer = xdp_umem_get_data(xs->umem, addr);
 		err = skb_store_bits(skb, 0, buffer, len);
-		if (unlikely(err)) {
+		if (unlikely(err) || xskq_reserve_addr(xs->umem->cq)) {
 			kfree_skb(skb);
 			goto out;
 		}
-- 
2.20.1


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200116170509.12787-1-sashal@kernel.org>
2020-01-16 16:58 ` [PATCH AUTOSEL 4.19 280/671] bpf: Add missed newline in verifier verbose log Sasha Levin
2020-01-16 16:59 ` [PATCH AUTOSEL 4.19 353/671] nfp: bpf: fix static check error through tightening shift amount adjustment Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 383/671] signal/bpfilter: Fix bpfilter_kernl to use send_sig not force_sig Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 390/671] net: core: support XDP generic on stacked devices Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 417/671] bpf: fix the check that forwarding is enabled in bpf_ipv6_fib_lookup Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 437/671] tools: bpftool: use correct argument in cgroup errors Sasha Levin
2020-01-16 17:01 ` Sasha Levin [this message]
2020-01-16 17:02 ` [PATCH AUTOSEL 4.19 483/671] net: fix bpf_xdp_adjust_head regression for generic-XDP Sasha Levin
2020-01-16 17:02 ` [PATCH AUTOSEL 4.19 494/671] tools: bpftool: fix arguments for p_err() in do_event_pipe() Sasha Levin
2020-01-16 17:02 ` [PATCH AUTOSEL 4.19 495/671] tools: bpftool: fix format strings and arguments for jsonw_printf() Sasha Levin
2020-01-16 17:02 ` [PATCH AUTOSEL 4.19 529/671] xsk: avoid store-tearing when assigning queues Sasha Levin
2020-01-16 17:02 ` [PATCH AUTOSEL 4.19 530/671] xsk: avoid store-tearing when assigning umem Sasha Levin
2020-01-16 17:03 ` [PATCH AUTOSEL 4.19 558/671] bpf: fix BTF limits Sasha Levin
2020-01-16 17:04 ` [PATCH AUTOSEL 4.19 602/671] xsk: Fix registration of Rx-only sockets Sasha Levin
2020-01-16 17:04 ` [PATCH AUTOSEL 4.19 603/671] bpf, offload: Unlock on error in bpf_offload_dev_create() Sasha Levin
2020-01-16 17:05 ` [PATCH AUTOSEL 4.19 666/671] samples/bpf: Fix broken xdp_rxq_info due to map order assumptions Sasha Levin

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200116170509.12787-198-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=bjorn.topel@intel.com \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=i.maximets@samsung.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=u9012063@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

BPF Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/bpf/0 bpf/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 bpf bpf/ https://lore.kernel.org/bpf \
		bpf@vger.kernel.org
	public-inbox-index bpf

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.bpf


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git