Re: NULL pointer dereference in usb_ifnum_to_if

2017-11-09 Thread Jaejoong Kim
Hi, 2017-11-09 3:40 GMT+09:00 Alan Stern : > On Wed, 8 Nov 2017, Philipp Kern wrote: > >> > If the bad access occurred because the uvc driver tried to access a >> > device that had been removed 5 seconds earlier, the most likely >> > explanation is a reference-counting error of some sort. >> >> Th

Re: NULL pointer dereference in usb_ifnum_to_if

2017-11-08 Thread Alan Stern
On Wed, 8 Nov 2017, Philipp Kern wrote: > > If the bad access occurred because the uvc driver tried to access a > > device that had been removed 5 seconds earlier, the most likely > > explanation is a reference-counting error of some sort. > > That sounds reasonable. Is there a way to debug this?

Re: NULL pointer dereference in usb_ifnum_to_if

2017-11-08 Thread Greg KH
On Wed, Nov 08, 2017 at 03:08:32PM +0100, Philipp Kern wrote: > Hi, > > I encountered a bunch of NULL pointer dereferences with the same stack > trace: > > [ 25.774914] usb 3-2: USB disconnect, device number 3 > [ 30.769840] BUG: unable to handle kernel NULL pointer dereference at (null) > [ 30.7

Re: NULL pointer dereference in usb_ifnum_to_if

2017-11-08 Thread Philipp Kern
Hi Alan, first of all thanks for your reply. My apologies for trying to condense too much and trying to read an unfamiliar codebase wrongly. :/ On 2017-11-08 17:08, Alan Stern wrote: On Wed, 8 Nov 2017, Philipp Kern wrote: Hi, I encountered a bunch of NULL pointer dereferences with the sam

Re: NULL pointer dereference in usb_ifnum_to_if

2017-11-08 Thread Alan Stern
On Wed, 8 Nov 2017, Philipp Kern wrote: > Hi, > > I encountered a bunch of NULL pointer dereferences with the same stack > trace: > > [ 25.774914] usb 3-2: USB disconnect, device number 3 > [ 30.769840] BUG: unable to handle kernel NULL pointer dereference at > (null) > [ 30.769846] IP: [] usb

NULL pointer dereference in usb_ifnum_to_if

2017-11-08 Thread Philipp Kern
Hi, I encountered a bunch of NULL pointer dereferences with the same stack trace: [ 25.774914] usb 3-2: USB disconnect, device number 3 [ 30.769840] BUG: unable to handle kernel NULL pointer dereference at (null) [ 30.769846] IP: [] usb_ifnum_to_if+0x25/0x60 [ 30.769851] PGD 0 [ 30.769852] O