This is a note to let you know that I've just added the patch titled mISDN: hfcmulti: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: misdn-hfcmulti-don-t-call-dev_kfree_skb-kfree_skb-un.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 775b532561a580ef5180ae0c47883ca811842ba6 Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Mon Dec 12 16:41:39 2022 +0800 mISDN: hfcmulti: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() [ Upstream commit 1232946cf522b8de9e398828bde325d7c41f29dd ] It is not allowed to call kfree_skb() or consume_skb() from hardware interrupt context or with hardware interrupts being disabled. skb_queue_purge() is called under spin_lock_irqsave() in handle_dmsg() and hfcm_l1callback(), kfree_skb() is called in them, to fix this, use skb_queue_splice_init() to move the dch->squeue to a free queue, also enqueue the tx_skb and rx_skb, at last calling __skb_queue_purge() to free the SKBs afer unlock. Fixes: af69fb3a8ffa ("Add mISDN HFC multiport driver") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Reviewed-by: Alexander Duyck <alexanderduyck@xxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/isdn/hardware/mISDN/hfcmulti.c b/drivers/isdn/hardware/mISDN/hfcmulti.c index 4f7eaa17fb27..e840609c50eb 100644 --- a/drivers/isdn/hardware/mISDN/hfcmulti.c +++ b/drivers/isdn/hardware/mISDN/hfcmulti.c @@ -3217,6 +3217,7 @@ static int hfcm_l1callback(struct dchannel *dch, u_int cmd) { struct hfc_multi *hc = dch->hw; + struct sk_buff_head free_queue; u_long flags; switch (cmd) { @@ -3245,6 +3246,7 @@ hfcm_l1callback(struct dchannel *dch, u_int cmd) l1_event(dch->l1, HW_POWERUP_IND); break; case HW_DEACT_REQ: + __skb_queue_head_init(&free_queue); /* start deactivation */ spin_lock_irqsave(&hc->lock, flags); if (hc->ctype == HFC_TYPE_E1) { @@ -3264,20 +3266,21 @@ hfcm_l1callback(struct dchannel *dch, u_int cmd) plxsd_checksync(hc, 0); } } - skb_queue_purge(&dch->squeue); + skb_queue_splice_init(&dch->squeue, &free_queue); if (dch->tx_skb) { - dev_kfree_skb(dch->tx_skb); + __skb_queue_tail(&free_queue, dch->tx_skb); dch->tx_skb = NULL; } dch->tx_idx = 0; if (dch->rx_skb) { - dev_kfree_skb(dch->rx_skb); + __skb_queue_tail(&free_queue, dch->rx_skb); dch->rx_skb = NULL; } test_and_clear_bit(FLG_TX_BUSY, &dch->Flags); if (test_and_clear_bit(FLG_BUSY_TIMER, &dch->Flags)) del_timer(&dch->timer); spin_unlock_irqrestore(&hc->lock, flags); + __skb_queue_purge(&free_queue); break; case HW_POWERUP_REQ: spin_lock_irqsave(&hc->lock, flags); @@ -3384,6 +3387,9 @@ handle_dmsg(struct mISDNchannel *ch, struct sk_buff *skb) case PH_DEACTIVATE_REQ: test_and_clear_bit(FLG_L2_ACTIVATED, &dch->Flags); if (dch->dev.D.protocol != ISDN_P_TE_S0) { + struct sk_buff_head free_queue; + + __skb_queue_head_init(&free_queue); spin_lock_irqsave(&hc->lock, flags); if (debug & DEBUG_HFCMULTI_MSG) printk(KERN_DEBUG @@ -3405,14 +3411,14 @@ handle_dmsg(struct mISDNchannel *ch, struct sk_buff *skb) /* deactivate */ dch->state = 1; } - skb_queue_purge(&dch->squeue); + skb_queue_splice_init(&dch->squeue, &free_queue); if (dch->tx_skb) { - dev_kfree_skb(dch->tx_skb); + __skb_queue_tail(&free_queue, dch->tx_skb); dch->tx_skb = NULL; } dch->tx_idx = 0; if (dch->rx_skb) { - dev_kfree_skb(dch->rx_skb); + __skb_queue_tail(&free_queue, dch->rx_skb); dch->rx_skb = NULL; } test_and_clear_bit(FLG_TX_BUSY, &dch->Flags); @@ -3424,6 +3430,7 @@ handle_dmsg(struct mISDNchannel *ch, struct sk_buff *skb) #endif ret = 0; spin_unlock_irqrestore(&hc->lock, flags); + __skb_queue_purge(&free_queue); } else ret = l1_event(dch->l1, hh->prim); break;