| Message ID | 20181226140934.12903-1-baijiaju1990@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | isdn: hisax: hfc_pci: Fix a possible concurrency use-after-free bug in HFCPCI_l1hw() | expand |
From: Jia-Ju Bai <baijiaju1990@gmail.com> Date: Wed, 26 Dec 2018 22:09:34 +0800 > In drivers/isdn/hisax/hfc_pci.c, the functions hfcpci_interrupt() and > HFCPCI_l1hw() may be concurrently executed. > > HFCPCI_l1hw() > line 1173: if (!cs->tx_skb) > > hfcpci_interrupt() > line 942: spin_lock_irqsave(); > line 1066: dev_kfree_skb_irq(cs->tx_skb); > > Thus, a possible concurrency use-after-free bug may occur > in HFCPCI_l1hw(). > > To fix these bugs, the calls to spin_lock_irqsave() and > spin_unlock_irqrestore() are added in HFCPCI_l1hw(), to protect the > access to cs->tx_skb. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Applied.
diff --git a/drivers/isdn/hisax/hfc_pci.c b/drivers/isdn/hisax/hfc_pci.c index ea0e4c6de3fb..0109e0e8bcb6 100644 --- a/drivers/isdn/hisax/hfc_pci.c +++ b/drivers/isdn/hisax/hfc_pci.c @@ -1170,11 +1170,13 @@ HFCPCI_l1hw(struct PStack *st, int pr, void *arg) if (cs->debug & L1_DEB_LAPD) debugl1(cs, "-> PH_REQUEST_PULL"); #endif + spin_lock_irqsave(&cs->lock, flags); if (!cs->tx_skb) { test_and_clear_bit(FLG_L1_PULL_REQ, &st->l1.Flags); st->l1.l1l2(st, PH_PULL | CONFIRM, NULL); } else test_and_set_bit(FLG_L1_PULL_REQ, &st->l1.Flags); + spin_unlock_irqrestore(&cs->lock, flags); break; case (HW_RESET | REQUEST): spin_lock_irqsave(&cs->lock, flags);
In drivers/isdn/hisax/hfc_pci.c, the functions hfcpci_interrupt() and HFCPCI_l1hw() may be concurrently executed. HFCPCI_l1hw() line 1173: if (!cs->tx_skb) hfcpci_interrupt() line 942: spin_lock_irqsave(); line 1066: dev_kfree_skb_irq(cs->tx_skb); Thus, a possible concurrency use-after-free bug may occur in HFCPCI_l1hw(). To fix these bugs, the calls to spin_lock_irqsave() and spin_unlock_irqrestore() are added in HFCPCI_l1hw(), to protect the access to cs->tx_skb. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/isdn/hisax/hfc_pci.c | 2 ++ 1 file changed, 2 insertions(+)