[PATCH 1/2] hp100: Fix a possible sleep-in-atomic bug in hp100_login_to_vg_hub

From: Jia-Ju Bai
Date: Wed Dec 13 2017 - 04:45:40 EST


The driver may sleep under a spinlock.
The function call path is:
hp100_set_multicast_list (acquire the spinlock)
hp100_login_to_vg_hub
schedule_timeout_interruptible --> may sleep

To fix it, schedule_timeout_interruptible is replaced with udelay.

This bug is found by my static analysis tool(DSAC) and checked by my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/net/ethernet/hp/hp100.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/hp/hp100.c b/drivers/net/ethernet/hp/hp100.c
index c8c7ad2..6addcbd 100644
--- a/drivers/net/ethernet/hp/hp100.c
+++ b/drivers/net/ethernet/hp/hp100.c
@@ -2636,8 +2636,7 @@ static int hp100_login_to_vg_hub(struct net_device *dev, u_short force_relogin)
do {
if (~(hp100_inb(VG_LAN_CFG_1) & HP100_LINK_UP_ST))
break;
- if (!in_interrupt())
- schedule_timeout_interruptible(1);
+ udelay(10);
} while (time_after(time, jiffies));

/* Start an addressed training and optionally request promiscuous port */
@@ -2672,8 +2671,7 @@ static int hp100_login_to_vg_hub(struct net_device *dev, u_short force_relogin)
do {
if (hp100_inb(VG_LAN_CFG_1) & HP100_LINK_CABLE_ST)
break;
- if (!in_interrupt())
- schedule_timeout_interruptible(1);
+ udelay(10);
} while (time_before(jiffies, time));

if (time_after_eq(jiffies, time)) {
@@ -2696,8 +2694,7 @@ static int hp100_login_to_vg_hub(struct net_device *dev, u_short force_relogin)
#endif
break;
}
- if (!in_interrupt())
- schedule_timeout_interruptible(1);
+ udelay(10);
} while (time_after(time, jiffies));
}

--
1.7.9.5