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atm: solos-pci: Fix potential deadlock on &cli_queue_lock
[ Upstream commitd5dba32b8f
] As &card->cli_queue_lock is acquired under softirq context along the following call chain from solos_bh(), other acquisition of the same lock inside process context should disable at least bh to avoid double lock. <deadlock #1> console_show() --> spin_lock(&card->cli_queue_lock) <interrupt> --> solos_bh() --> spin_lock(&card->cli_queue_lock) This flaw was found by an experimental static analysis tool I am developing for irq-related deadlock. To prevent the potential deadlock, the patch uses spin_lock_bh() on the card->cli_queue_lock under process context code consistently to prevent the possible deadlock scenario. Fixes:9c54004ea7
("atm: Driver for Solos PCI ADSL2+ card.") Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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1 changed files with 2 additions and 2 deletions
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@ -449,9 +449,9 @@ static ssize_t console_show(struct device *dev, struct device_attribute *attr,
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struct sk_buff *skb;
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unsigned int len;
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spin_lock(&card->cli_queue_lock);
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spin_lock_bh(&card->cli_queue_lock);
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skb = skb_dequeue(&card->cli_queue[SOLOS_CHAN(atmdev)]);
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spin_unlock(&card->cli_queue_lock);
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spin_unlock_bh(&card->cli_queue_lock);
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if(skb == NULL)
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return sprintf(buf, "No data.\n");
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