Bug 16473 (mantis-oops)
| Summary: | mantis driver: Oops: BUG: unable to handle kernel NULL pointer dereference | ||
|---|---|---|---|
| Product: | v4l-dvb | Reporter: | Ronny (bRainKiller_01) |
| Component: | dvb-other | Assignee: | Alan (alan) |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | high | CC: | alan, florian, idl0r |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 2.6.34.1 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
complete trace log
check for null pointer before calling dvb_unregister_frontend or dvb_frontend_detach |
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Created attachment 27276 [details]
check for null pointer before calling dvb_unregister_frontend or dvb_frontend_detach
well, a quick patch
IMHO, it would be much better if dvb_frontend_detach, dvb_unregister_frontend and so forth perform a NULL-check instead of blindly accessing a class member.
I can reproduce it here with 2.6.{34,35,36}.
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_DEV=y
CONFIG_DVB_CORE=y
CONFIG_MEDIA_ATTACH=y
CONFIG_MANTIS_CORE=m
CONFIG_DVB_MANTIS=m
CONFIG_DVB_FE_CUSTOMISE=y
CONFIG_DVB_TDA10023=m
and CONFIG_DVB_PLL=y (Auto selected)
modprobe mantis and it will fail.
It doesn't fail if CONFIG_DVB_TDA10023=y.
A patch referencing this bug report has been merged in Linux v3.7-rc1: commit e1d45ae10aea8e8a403e5d96bf5902ee670007ff Author: Alan Cox <alan@linux.intel.com> Date: Thu Aug 9 12:33:52 2012 -0300 [media] mantis: fix silly crash case |
Created attachment 27275 [details] complete trace log I tried to load the mantis module but I guess had some required frontend modules disabled. The mantis module could not be loaded and it failed with a null pointer exception. Jun 30 21:33:24 [kernel] BUG: unable to handle kernel NULL pointer dereference at 0000000000000308 Jun 30 21:33:24 [kernel] IP: [<ffffffff81447ccf>] dvb_unregister_frontend+0xf/0x100 Jun 30 21:33:24 [kernel] PGD 22d13b067 PUD 22c938067 PMD 0