Bug#335969: linux-2.6: oops in cdc-acm when unplugging USB modem
Package: linux-2.6
Version: 2.6.12-10
Severity: normal
If a USB modem (in my case a Motorola phone) is unplugged while the
cdc-acm module is managing a PPP connection, the kernel oopses. If,
however, you kill the ppp connection and _then_ unplug the modem, all
is well.
This is not a new problem, btw, I've had it with all the 2.6 kernels
I've used. I'm finally reporting it because it seems nobody else is
noticing or complaining.
Here's the oops:
Oct 26 10:24:56 tytlal kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000
Oct 26 10:24:56 tytlal kernel: printing eip:
Oct 26 10:24:56 tytlal kernel: c01c2646
Oct 26 10:24:56 tytlal kernel: *pde = 00000000
Oct 26 10:24:56 tytlal kernel: Oops: 0000 [#1]
Oct 26 10:24:56 tytlal kernel: Modules linked in: nls_cp437 cifs ppp_deflate zlib_deflate bsd_comp ppp_async crc_ccitt ppp_generic slhc
cdc_acm snd_intel8x0 snd_ac97_codec hostap_crypt_ccmp hostap_crypt_tkip hostap binfmt_misc autofs4 ipv6 af_packet rtcmosram smapi thin
kpad radeon drm cpufreq_userspace cpufreq_powersave speedstep_ich speedstep_lib freq_table apm ide_scsi scsi_mod pcmcia e100 mii yenta_
socket rsrc_nonstatic pcmcia_core snd_pcm_oss snd_mixer_oss snd_pcm tpm_atmel tpm_nsc tpm snd_timer i2c_i801 snd soundcore i2c_core uhc
i_hcd snd_page_alloc usbcore intel_agp pci_hotplug agpgart ide_cd cdrom psmouse serio_raw evdev mousedev ext3 jbd mbcache ide_disk ide_
generic piix pdc202xx_new hpt34x cs5520 hpt366 sc1200 via82cxxx serverworks rz1000 cy82c693 cs5530 trm290 aec62xx slc90e66 opti621 trif
lex amd74xx siimage cmd64x pdc202xx_old atiixp ns87415 alim15x3 generic sis5513 ide_core aes_i586 dm_crypt dm_mod unix fbcon tileblit f
ont bitblit vesafb cfbcopyarea cfbimgblt cfbfillrect softcursor capability common
Oct 26 10:24:56 tytlal kernel: ap
Oct 26 10:24:56 tytlal kernel: CPU: 0
Oct 26 10:24:56 tytlal kernel: EIP: 0060:[get_kobj_path_length+38/64] Not tainted VLI
Oct 26 10:24:56 tytlal kernel: EFLAGS: 00210246 (2.6.12-1-686)
Oct 26 10:24:56 tytlal kernel: EIP is at get_kobj_path_length+0x26/0x40
Oct 26 10:24:56 tytlal kernel: eax: 00000000 ebx: 00000000 ecx: ffffffff edx: d8f944f8
Oct 26 10:24:56 tytlal kernel: esi: 00000001 edi: 00000000 ebp: ffffffff esp: dd1cbd50
Oct 26 10:24:56 tytlal kernel: ds: 007b es: 007b ss: 0068
Oct 26 10:24:56 tytlal kernel: Process pppd (pid: 29069, threadinfo=dd1ca000 task=c1efdaa0)
Oct 26 10:24:56 tytlal kernel: Stack: d62dac37 d8f944d4 e00cf378 d8f944f8 c01c26ef d8f944f8 d62dac88 c03308a8
Oct 26 10:24:56 tytlal kernel: d62dac37 d8f944d4 e00cf378 e00cf8e8 c0223b3d d8f944f8 000000d0 c02bf71c
Oct 26 10:24:56 tytlal kernel: dd1cbdcc d62dac29 e00cf360 c02bf71e c0330b00 00000000 00000000 d62dac37
Oct 26 10:24:56 tytlal kernel: Call Trace:
Oct 26 10:24:56 tytlal kernel: [kobject_get_path+31/128] kobject_get_path+0x1f/0x80
Oct 26 10:24:56 tytlal kernel: [class_hotplug+61/496] class_hotplug+0x3d/0x1f0
Oct 26 10:24:56 tytlal kernel: [class_hotplug+0/496] class_hotplug+0x0/0x1f0
Oct 26 10:24:56 tytlal kernel: [kobject_hotplug+479/752] kobject_hotplug+0x1df/0x2f0
Oct 26 10:24:56 tytlal kernel: [class_device_del+170/208] class_device_del+0xaa/0xd0
Oct 26 10:24:56 tytlal kernel: [class_device_unregister+16/32] class_device_unregister+0x10/0x20
Oct 26 10:24:56 tytlal kernel: [pg0+679171319/1069827072] acm_tty_close+0xb7/0x100 [cdc_acm]
Oct 26 10:24:56 tytlal kernel: [release_dev+355/1808] release_dev+0x163/0x710
Oct 26 10:24:56 tytlal kernel: [link_path_walk+102/288] link_path_walk+0x66/0x120
Oct 26 10:24:56 tytlal kernel: [permission+210/288] permission+0xd2/0x120
Oct 26 10:24:56 tytlal kernel: [tty_open+357/736] tty_open+0x165/0x2e0
Oct 26 10:24:56 tytlal kernel: [chrdev_open+139/368] chrdev_open+0x8b/0x170
Oct 26 10:24:56 tytlal kernel: [get_empty_filp+145/272] get_empty_filp+0x91/0x110
Oct 26 10:24:56 tytlal kernel: [dentry_open+214/528] dentry_open+0xd6/0x210
Oct 26 10:24:56 tytlal kernel: [filp_open+92/112] filp_open+0x5c/0x70
Oct 26 10:24:56 tytlal kernel: [get_unused_fd+87/192] get_unused_fd+0x57/0xc0
Oct 26 10:24:56 tytlal kernel: [sys_open+73/144] sys_open+0x49/0x90
Oct 26 10:24:56 tytlal kernel: [sysenter_past_esp+84/117] sysenter_past_esp+0x54/0x75
Oct 26 10:24:56 tytlal kernel: Code: 27 00 00 00 00 55 bd ff ff ff ff 57 56 be 01 00 00 00 53 31 db 8b 54 24 14 8d b6 00 00 00 00 8d bf
00 00 00 00 8b 3a 89 e9 89 d8 <f2> ae f7 d1 49 8b 52 24 8d 74 31 01 85 d2 75 ea 5b 89 f0 5e 5f
Oct 26 10:25:14 tytlal kernel: <6>usb 2-1: USB disconnect, address 6
-- System Information:
Debian Release: testing/unstable
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: i386 (i686)
Shell: /bin/sh linked to /bin/bash
Kernel: Linux 2.6.12-1-686
Locale: LANG=en_US, LC_CTYPE=en_US (charmap=ISO-8859-1)
Versions of packages linux-image-2.6.12-1-686 depends on:
ii coreutils [fileutils] 5.2.1-2.1 The GNU core utilities
ii initrd-tools 0.1.84 tools to create initrd image for p
ii module-init-tools 3.2-pre9-3 tools for managing Linux kernel mo
linux-image-2.6.12-1-686 recommends no packages.
-- no debconf information
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