Bug 49491

Summary:	NULL pointer dereference in page_waitqueue during FireWire I/O
Product:	Drivers	Reporter:	Stefan Richter (stefanr)
Component:	IEEE1394	Assignee:	drivers_ieee1394
Status:	RESOLVED UNREPRODUCIBLE
Severity:	normal
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.2.0-26-generic (Ubuntu 12.04)	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	panic screenshot 1 panic screenshot 2

Description Stefan Richter 2012-10-24 21:50:29 UTC

Reported in a thread with subject: "diag" on linux1394-user (http://marc.info/?t=135092061600002):  After about a minute of I/O by a FireWire hardware testing tool called fwdiag which performs asynchronous traffic between two OHCI-1394 controllers (https://gitorious.org/~eviljoel/cfk_misc/fwdiag-cleanup/), a NULL pointer dereference occurred.

pointer: 0000000000000690
in page_waitqueue+06e/0x90
call trace:
unlock_page+0x1d/0x40
filemap_fault+0x3ba/0x3e0
__do_fault+0x72/0x550
? rb_insert_color+0x110/0x150
handle_pte_fault+0xfa0x200
? cpumask_any_but+0x2d/0x40
handle_mm_fault+0x1f8/0x350
do_page_fault+0x150/0x520
? mprotect_fixup+0x17d/0x2b0
? sys_mprotect+0x1f0/0x250
page_fault+0x25/0x30

Comment 1 Stefan Richter 2012-10-24 21:55:53 UTC

Created attachment 84731 [details]
panic screenshot 1

Comment 2 Stefan Richter 2012-10-24 21:56:38 UTC

Created attachment 84741 [details]
panic screenshot 2

Comment 3 Stefan Richter 2012-10-25 19:53:18 UTC

Happened once on the reporter's machine and hasn't been reproduced by him or by the fwdiag developer.