[PATCH 6.1 0893/1146] mISDN: hfcmulti: dont call dev_kfree_skb/kfree_skb() under spin_lock_irqsave()

Greg Kroah-Hartman
2022-12-28T16:47:54Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ 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@huawei.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/isdn/hardware/mISDN/hfcmulti.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

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;
--
2.35.1