On Wed, 12 Oct 2011 23:59:26 +0200 Antonio Ospite <ospite@xxxxxxxxxxxxxxxxx> wrote: > The change in 8280b66 does not cover the case when v4l2_dev is already > NULL, fix that. > > With a Kinect sensor, seen as an USB camera using GSPCA in this context, > a NULL pointer dereference BUG can be triggered by just unplugging the > device after the camera driver has been loaded. > > Signed-off-by: Antonio Ospite <ospite@xxxxxxxxxxxxxxxxx> > --- > Hi, > > can anyone reproduce this? > Ping. David, does the change below fix it for you, I sent the patch last week. Regards, Antonio > This is the complete trace, I left it out of the commit message, but feel free > to include it if you think it is worth it. > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 > IP: [<ffffffffa10cc604>] v4l2_device_release+0xb8/0xe8 [videodev] > PGD 0 > Oops: 0000 [#1] SMP > CPU 0 > Modules linked in: snd_usb_audio snd_usbmidi_lib gspca_kinect gspca_main > videodev media v4l2_compat_ioctl32 hidp snd_hrtimer ebtable_nat ebtables > powernow_k8 mperf cpufreq_powersave cpufreq_conservative cpufreq_stats > cpufreq_userspace ipt_MASQUERADE xt_CHECKSUM bridge stp ppdev lp bnep rfcomm > tun sit tunnel4 ip6table_raw ip6table_mangle ip6t_REJECT ip6t_LOG > nf_conntrack_ipv6 nf_defrag_ipv6 ip6t_rt ip6table_filter ip6_tables decnet > binfmt_misc uinput fuse xt_tcpudp ipt_REJECT ipt_ULOG xt_limit xt_state > xt_multiport iptable_filter iptable_nat nf_nat nf_conntrack_ipv4 nf_conntrack > nf_defrag_ipv4 iptable_mangle iptable_raw ip_tables x_tables nfsd nfs lockd > fscache auth_rpcgss nfs_acl sunrpc it87 hwmon_vid loop kvm_amd kvm > snd_hda_codec_hdmi snd_hda_codec_via nvidia(P) snd_hda_intel snd_hda_codec > snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_midi snd_rawmidi cryptd > aes_x86_64 snd_seq_midi_event aes_generic ecb snd_seq btusb bluetooth evdev > snd_timer snd_seq_device edac_core parport_pc pcspkr parport rfkill snd > edac_mce_amd k8temp crc16 soundcore mxm_wmi snd_page_alloc asus_atk0110 shpchp > video pci_hotplug i2c_nforce2 wmi i2c_core processor thermal_sys button ext3 > jbd mbcache dm_mod sg sd_mod sr_mod crc_t10dif cdrom ata_generic usb_storage > usbhid hid uas ahci libahci pata_amd libata scsi_mod forcedeth floppy ohci_hcd > ehci_hcd usbcore [last unloaded: scsi_wait_scan] > > Pid: 125, comm: khubd Tainted: P 3.1.0-rc9-ao2 #3 System manufacturer System Product Name/M3N78-VM > RIP: 0010:[<ffffffffa10cc604>] [<ffffffffa10cc604>] v4l2_device_release+0xb8/0xe8 [videodev] > RSP: 0018:ffff88011639fc10 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff8800ca61a088 RCX: 0000000000000001 > RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffffa10db000 > RBP: 0000000000000000 R08: ffffffff8119b320 R09: ffffffff8119b320 > R10: 0000000000000001 R11: 0000000000000001 R12: ffff8800ca61a000 > R13: ffffffff8164ffb0 R14: 0000000000000000 R15: 000000000000001f > FS: 00007f61275f37a0(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 0000000000000090 CR3: 00000001150de000 CR4: 00000000000006f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process khubd (pid: 125, threadinfo ffff88011639e000, task ffff88011639d590) > Stack: > ffff8800ca5d8380 ffff8800ca61a098 ffff8800ca66c200 ffffffff81232e94 > ffff8800ca61a0d0 ffffffff8119a7fa ffffffff8119b320 ffff8800ca61a0d0 > ffffffff8119a7ab ffff8800ca56dc00 ffffffffa10e1068 ffffffff8119b93a > Call Trace: > [<ffffffff81232e94>] ? device_release+0x41/0x72 > [<ffffffff8119a7fa>] ? kobject_release+0x4f/0x6c > [<ffffffff8119b320>] ? add_uevent_var+0xdc/0xdc > [<ffffffff8119a7ab>] ? kobject_del+0x2d/0x2d > [<ffffffff8119b93a>] ? kref_put+0x3e/0x47 > [<ffffffffa0039f15>] ? usb_unbind_interface+0x4d/0x111 [usbcore] > [<ffffffff81235b9b>] ? __device_release_driver+0x7d/0xc9 > [<ffffffff81235c02>] ? device_release_driver+0x1b/0x27 > [<ffffffff81235804>] ? bus_remove_device+0x7c/0x8b > [<ffffffff812337e6>] ? device_del+0x129/0x177 > [<ffffffffa00384f7>] ? usb_disable_device+0x6a/0x159 [usbcore] > [<ffffffffa003250c>] ? usb_disconnect+0x8c/0x108 [usbcore] > [<ffffffffa00324ed>] ? usb_disconnect+0x6d/0x108 [usbcore] > [<ffffffffa0033bc5>] ? hub_thread+0x58e/0xec6 [usbcore] > [<ffffffff81036e08>] ? set_next_entity+0x32/0x52 > [<ffffffff8105ec53>] ? add_wait_queue+0x3c/0x3c > [<ffffffffa0033637>] ? usb_remote_wakeup+0x2f/0x2f [usbcore] > [<ffffffff8105e60d>] ? kthread+0x76/0x7e > [<ffffffff81332f34>] ? kernel_thread_helper+0x4/0x10 > [<ffffffff8105e597>] ? kthread_worker_fn+0x139/0x139 > [<ffffffff81332f30>] ? gs_change+0x13/0x13 > Code: 0d a1 e8 7a ec 25 e0 48 8b 83 78 02 00 00 48 85 c0 74 18 48 83 78 08 00 74 11 83 bb b0 02 00 00 03 74 08 4c 89 e7 e8 03 5a ff ff > 83 bd 90 00 00 00 00 b8 00 00 00 00 4c 89 e7 48 0f 44 e8 ff > RIP [<ffffffffa10cc604>] v4l2_device_release+0xb8/0xe8 [videodev] > RSP <ffff88011639fc10> > CR2: 0000000000000090 > ---[ end trace 99f7feddc91f30d6 ]--- > > Thanks, > Antonio Ospite > http://ao2.it > > drivers/media/video/v4l2-dev.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c > index d721565..a5c9ed1 100644 > --- a/drivers/media/video/v4l2-dev.c > +++ b/drivers/media/video/v4l2-dev.c > @@ -181,7 +181,7 @@ static void v4l2_device_release(struct device *cd) > * TODO: In the long run all drivers that use v4l2_device should use the > * v4l2_device release callback. This check will then be unnecessary. > */ > - if (v4l2_dev->release == NULL) > + if (v4l2_dev && v4l2_dev->release == NULL) > v4l2_dev = NULL; > > /* Release video_device and perform other > -- > 1.7.7 > > -- Antonio Ospite http://ao2.it PGP public key ID: 0x4553B001 A: Because it messes up the order in which people normally read text. See http://en.wikipedia.org/wiki/Posting_style Q: Why is top-posting such a bad thing?
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