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authorJuergen Gross <jgross@suse.com>2021-02-02 08:09:38 +0100
committerJakub Kicinski <kuba@kernel.org>2021-02-04 19:54:37 +0100
commitec7d8e7dd3a59528e305a18e93f1cb98f7faf83b (patch)
tree862d98a349b7ce7e275630f5fa2c27ed884725ef /drivers/net/xen-netback
parentselftests/tls: fix selftest with CHACHA20-POLY1305 (diff)
downloadlinux-ec7d8e7dd3a59528e305a18e93f1cb98f7faf83b.tar.xz
linux-ec7d8e7dd3a59528e305a18e93f1cb98f7faf83b.zip
xen/netback: avoid race in xenvif_rx_ring_slots_available()
Since commit 23025393dbeb3b8b3 ("xen/netback: use lateeoi irq binding") xenvif_rx_ring_slots_available() is no longer called only from the rx queue kernel thread, so it needs to access the rx queue with the associated queue held. Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com> Fixes: 23025393dbeb3b8b3 ("xen/netback: use lateeoi irq binding") Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Wei Liu <wl@xen.org> Link: https://lore.kernel.org/r/20210202070938.7863-1-jgross@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/xen-netback')
-rw-r--r--drivers/net/xen-netback/rx.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
index b8febe1d1bfd..accc991d153f 100644
--- a/drivers/net/xen-netback/rx.c
+++ b/drivers/net/xen-netback/rx.c
@@ -38,10 +38,15 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
RING_IDX prod, cons;
struct sk_buff *skb;
int needed;
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->rx_queue.lock, flags);
skb = skb_peek(&queue->rx_queue);
- if (!skb)
+ if (!skb) {
+ spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
return false;
+ }
needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
if (skb_is_gso(skb))
@@ -49,6 +54,8 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
if (skb->sw_hash)
needed++;
+ spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
+
do {
prod = queue->rx.sring->req_prod;
cons = queue->rx.req_cons;