6.6-stable review patch. If anyone has any objections, please let me know.
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From: I Viswanath viswanathiyyappan@gmail.com
[ Upstream commit 958baf5eaee394e5fd976979b0791a875f14a179 ]
syzbot reported WARNING in rtl8150_start_xmit/usb_submit_urb. This is the sequence of events that leads to the warning:
rtl8150_start_xmit() { netif_stop_queue(); usb_submit_urb(dev->tx_urb); }
rtl8150_set_multicast() { netif_stop_queue(); netif_wake_queue(); <-- wakes up TX queue before URB is done }
rtl8150_start_xmit() { netif_stop_queue(); usb_submit_urb(dev->tx_urb); <-- double submission }
rtl8150_set_multicast being the ndo_set_rx_mode callback should not be calling netif_stop_queue and notif_start_queue as these handle TX queue synchronization.
The net core function dev_set_rx_mode handles the synchronization for rtl8150_set_multicast making it safe to remove these locks.
Reported-and-tested-by: syzbot+78cae3f37c62ad092caa@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=78cae3f37c62ad092caa Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Tested-by: Michal Pecio michal.pecio@gmail.com Signed-off-by: I Viswanath viswanathiyyappan@gmail.com Link: https://patch.msgid.link/20250924134350.264597-1-viswanathiyyappan@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/rtl8150.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c index ddff6f19ff98e..92add3daadbb1 100644 --- a/drivers/net/usb/rtl8150.c +++ b/drivers/net/usb/rtl8150.c @@ -664,7 +664,6 @@ static void rtl8150_set_multicast(struct net_device *netdev) rtl8150_t *dev = netdev_priv(netdev); u16 rx_creg = 0x9e;
- netif_stop_queue(netdev); if (netdev->flags & IFF_PROMISC) { rx_creg |= 0x0001; dev_info(&netdev->dev, "%s: promiscuous mode\n", netdev->name); @@ -678,7 +677,6 @@ static void rtl8150_set_multicast(struct net_device *netdev) rx_creg &= 0x00fc; } async_set_registers(dev, RCR, sizeof(rx_creg), rx_creg); - netif_wake_queue(netdev); }
static netdev_tx_t rtl8150_start_xmit(struct sk_buff *skb,