Re: [BUG] skge: a possible sleep-in-atomic bug in skge_remove

Stephen Hemminger
2017-12-13T05:18:55Z

On Tue, 12 Dec 2017 20:57:01 -0500 (EST)
David Miller <davem@davemloft.net> wrote:

> From: Stephen Hemminger <stephen@networkplumber.org>
> Date: Tue, 12 Dec 2017 10:22:40 -0800
>
> > On Tue, 12 Dec 2017 08:34:45 -0500 (EST)
> > David Miller <davem@davemloft.net> wrote:
> >
> >> From: Jia-Ju Bai <baijiaju1990@gmail.com>
> >> Date: Tue, 12 Dec 2017 16:38:12 +0800
> >>
> >> > According to drivers/net/ethernet/marvell/skge.c, the driver may sleep
> >> > under a spinlock.
> >> > The function call path is:
> >> > skge_remove (acquire the spinlock)
> >> > free_irq --> may sleep
> >> >
> >> > I do not find a good way to fix it, so I only report.
> >> > This possible bug is found by my static analysis tool (DSAC) and
> >> > checked by my code review.
> >>
> >> This was added by:
> >>
> >> commit a9e9fd7182332d0cf5f3e601df3e71dd431b70d7
> >> Author: Stephen Hemminger <shemminger@vyatta.com>
> >> Date: Tue Sep 27 13:41:37 2011 -0400
> >>
> >> skge: handle irq better on single port card
> >>
> >> I think the free_irq() can be moved below the unlock.
> >>
> >> Stephen, please take a look.
> >
> > The IRQ was being free twice.
> > How did you see it, I really doubt any multi-port SKGE cards
> > still exist.
>
> He sees it by reading the code, please take a look at this
> and move the free_irq() out of the spin locked section since
> it can sleep.

Thanks, I was hoping for some automated static analysis tool.