This small program causes kernel oops: #include <fcntl.h> #include <poll.h> int main() { int fd; struct pollfd pfd; fd = open("/dev/net/tun", O_RDWR); pfd.fd = fd; pfd.events = POLLIN | POLLOUT; poll(&pfd, 1, 0); } Software versions: Gnu C 4.4.0 Gnu make 3.81 binutils 2.19.51.20090622 util-linux 2.15.1-rc1 mount support module-init-tools 3.8 e2fsprogs 1.41.5 reiserfsprogs 3.6.21 pcmciautils 014 Linux C Library 2.9 Dynamic linker (ldd) 2.9 Procps 3.2.8 Net-tools 1.60 Kbd 1.15 Sh-utils 7.4 wireless-tools 29 Modules Loaded tun ppp_async option usb_storage binfmt_misc ppdev kqemu sbp2 lp parport snd_hda_codec_realtek joydev snd_hda_intel snd_hda_codec snd_pcm_oss snd_mixer_oss snd_pcm arc4 snd_seq_dummy snd_seq_oss ecb snd_seq_midi snd_rawmidi ath5k snd_seq_midi_event snd_seq snd_timer snd_seq_device pcmcia mac80211 nsc_ircc ath psmouse snd sdhci_pci sdhci acer_wmi yenta_socket rsrc_nonstatic uvcvideo tifm_7xx1 tifm_core serio_raw soundcore iTCO_wdt iTCO_vendor_support irda led_class pcmcia_core videodev v4l1_compat v4l2_compat_ioctl32 cfg80211 pcspkr snd_page_alloc crc_ccitt ohci1394 ieee1394 tg3 usbhid fbcon tileblit font bitblit softcursor i915 drm i2c_algo_bit video output intel_agp dmesg output: [14610.772456] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [14610.772464] IP: [<ffffffffa0455b63>] tun_chr_poll+0x33/0xf0 [tun] [14610.772473] PGD 2885f067 PUD 2bd8f067 PMD 0 [14610.772477] Oops: 0000 [#4] SMP [14610.772480] last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:29/PNP0C09:00/PNP0C0A:00/power_supply/BAT0/voltage_now [14610.772484] CPU 0 [14610.772486] Modules linked in: tun ppp_async option usb_storage binfmt_misc ppdev kqemu sbp2 lp parport snd_hda_codec_realtek joydev snd_hda_intel snd_hda_codec snd_pcm_oss snd_mixer_oss snd_pcm arc4 snd_seq_dummy snd_seq_oss ecb snd_seq_midi snd_rawmidi ath5k snd_seq_midi_event snd_seq snd_timer snd_seq_device pcmcia mac80211 nsc_ircc ath psmouse snd sdhci_pci sdhci acer_wmi yenta_socket rsrc_nonstatic uvcvideo tifm_7xx1 tifm_core serio_raw soundcore iTCO_wdt iTCO_vendor_support irda led_class pcmcia_core videodev v4l1_compat v4l2_compat_ioctl32 cfg80211 pcspkr snd_page_alloc crc_ccitt ohci1394 ieee1394 tg3 usbhid fbcon tileblit font bitblit softcursor i915 drm i2c_algo_bit video output intel_agp [14610.772532] Pid: 7896, comm: tun-crash Tainted: G D 2.6.31-rc1-git10-generic-vanilla #1 Extensa 5220 [14610.772534] RIP: 0010:[<ffffffffa0455b63>] [<ffffffffa0455b63>] tun_chr_poll+0x33/0xf0 [tun] [14610.772539] RSP: 0018:ffff88002bdbdb08 EFLAGS: 00010246 [14610.772541] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88002bdbdb88 [14610.772544] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88007add0fe0 [14610.772546] RBP: ffff88002bdbdb28 R08: 00007feea2ddb2e0 R09: 00007feea2def160 [14610.772548] R10: 00007fffc0c0a150 R11: 0000000000000246 R12: ffff88002bdf8000 [14610.772550] R13: 0000000000000000 R14: ffff88002bdf8000 R15: 0000000000000000 [14610.772553] FS: 00007feea2fdf6f0(0000) GS:ffff88000199d000(0000) knlGS:0000000000000000 [14610.772555] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [14610.772557] CR2: 0000000000000080 CR3: 000000002bdf7000 CR4: 00000000000006b0 [14610.772560] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [14610.772562] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [14610.772565] Process tun-crash (pid: 7896, threadinfo ffff88002bdbc000, task ffff880028838000) [14610.772566] Stack: [14610.772568] ffff88002bdbdf04 ffff88002bdbde0c ffff88002bdbde04 ffff88002bdf8000 [14610.772572] <0> ffff88002bdbdf38 ffffffff8111eef5 ffff88002bdbdb58 01ffffff810ccaf2 [14610.772575] <0> 00007fffc0c0a3d0 0000000000000000 ffff88002bdbdb88 00000001810e221d [14610.772580] Call Trace: [14610.772587] [<ffffffff8111eef5>] do_sys_poll+0x235/0x510 [14610.772591] [<ffffffff8111eaf0>] ? __pollwait+0x0/0xf0 [14610.772596] [<ffffffff81504b49>] ? _spin_lock+0x9/0x10 [14610.772598] [<ffffffff81504b49>] ? _spin_lock+0x9/0x10 [14610.772601] [<ffffffff811219de>] ? __d_lookup+0x12e/0x150 [14610.772605] [<ffffffffa0455862>] ? tun_chr_open+0x32/0xe0 [tun] [14610.772609] [<ffffffffa0455862>] ? tun_chr_open+0x32/0xe0 [tun] [14610.772612] [<ffffffff81504dcd>] ? unlock_kernel+0x2d/0x40 [14610.772617] [<ffffffff812e351b>] ? misc_open+0x1bb/0x200 [14610.772622] [<ffffffff811118da>] ? chrdev_open+0xfa/0x1b0 [14610.772626] [<ffffffff810cb849>] ? find_get_page+0x19/0xa0 [14610.772629] [<ffffffff810cd831>] ? filemap_fault+0xb1/0x450 [14610.772632] [<ffffffff810ccaf2>] ? unlock_page+0x22/0x30 [14610.772636] [<ffffffff810e4ce9>] ? __do_fault+0x419/0x4e0 [14610.772639] [<ffffffff810e8d12>] ? handle_mm_fault+0x1b2/0x950 [14610.772643] [<ffffffff811271bb>] ? mntput_no_expire+0x2b/0x100 [14610.772647] [<ffffffff81030389>] ? default_spin_lock_flags+0x9/0x10 [14610.772651] [<ffffffff81260f9a>] ? __up_read+0x9a/0xc0 [14610.772656] [<ffffffff81073199>] ? up_read+0x9/0x10 [14610.772659] [<ffffffff8111f3b7>] sys_poll+0x77/0x110 [14610.772663] [<ffffffff81011ec2>] system_call_fastpath+0x16/0x1b [14610.772665] Code: 48 89 1c 24 4c 89 64 24 08 49 89 fc 4c 89 6c 24 10 4c 89 74 24 18 48 89 f3 48 8b bf a0 00 00 00 e8 73 f6 ff ff 48 85 db 49 89 c5 <4c> 8b b0 80 00 00 00 0f 85 98 00 00 00 49 8d 45 18 49 39 45 18 [14610.772694] RIP [<ffffffffa0455b63>] tun_chr_poll+0x33/0xf0 [tun] [14610.772698] RSP <ffff88002bdbdb08> [14610.772699] CR2: 0000000000000080 [14610.772702] ---[ end trace 9813be85d2509042 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html