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authorJia-Ju Bai <baijiaju1990@gmail.com>2018-12-26 22:09:34 +0800
committerDavid S. Miller <davem@davemloft.net>2018-12-28 21:27:31 -0800
commit7418e6520f22a2e35815122fa5a53d5bbfa2c10f (patch)
tree732d18013dc3e3eb26f1c5d2b9b9c9d541b8ed1c /drivers/isdn
parentf9fc54d313fab2834f44f516459cdc8ac91d797f (diff)
isdn: hisax: hfc_pci: Fix a possible concurrency use-after-free bug in HFCPCI_l1hw()
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> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn')
-rw-r--r--drivers/isdn/hisax/hfc_pci.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/isdn/hisax/hfc_pci.c b/drivers/isdn/hisax/hfc_pci.c
index 5b719b561860..81dd465afcf4 100644
--- a/drivers/isdn/hisax/hfc_pci.c
+++ b/drivers/isdn/hisax/hfc_pci.c
@@ -1169,11 +1169,13 @@ 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);