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When inadvertently hot-unplugging a WT-220U USB DVB-T receiver with 2.6.24, I was met with an oops [1]. The problem is relevant to 2.6.25/26-rc also. dvb_frontend_init() was called either from re-creation of the kdvb-fe0 thread - seems unlikely, or someone called dvb_frontend_reinitialise(), causing this path in the thread - really unlikely, as I can't find any call-site for it. Either way, quite a number of drivers call dvb_usb_generic_rw() [2] without checking the validity of the relevant member in the dvb_usb_device struct - which had changed. Having dvb_usb_generic_rw() sanity-check and fail (rather than loading from 0x120) seems reasonable defensive programming [3], in light of it being called in this way. The problem with this, is that drivers don't check the return code of the init call [4]. Does it make sense to cook a patch which allows the failure to be propagated back up, or am I missing something else? Thanks, Daniel <whoops, hot unplug> [83711.538485] dvb-usb: bulk message failed: -71 (1/0) [83711.538875] dvb-usb: bulk message failed: -71 (1/0) [83711.538899] usb 7-5: USB disconnect, address 3 [83711.538905] dvb-usb: bulk message failed: -22 (1/0) [83711.538924] dvb-usb: bulk message failed: -22 (1/0) [83711.538943] dvb-usb: bulk message failed: -22 (1/0) [83711.588979] dvb-usb: bulk message failed: -22 (1/0) [83711.589031] dvb-usb: bulk message failed: -22 (1/0) [83711.589078] dvb-usb: bulk message failed: -22 (1/0) [83711.589122] dvb-usb: bulk message failed: -22 (1/0) [83711.589167] dvb-usb: bulk message failed: -22 (1/0) [83711.639233] dvb-usb: bulk message failed: -22 (1/0) [83711.639282] dvb-usb: bulk message failed: -22 (1/0) [83711.639330] dvb-usb: bulk message failed: -22 (1/0) [83711.639374] dvb-usb: bulk message failed: -22 (1/0) [83711.639421] dvb-usb: bulk message failed: -22 (1/0) [83711.658391] dvb-usb: bulk message failed: -22 (1/0) [83768.174281] dvb-usb: bulk message failed: -22 (2/-32512) [83768.174350] Unable to handle kernel NULL pointer dereference<6>dvb-usb: WideView WT-220U PenType Receiver (Typhoon/Freecom) successfully deinitialized and disconnected. [83768.174459] at 0000000000000120 RIP: [83768.174459] [<ffffffff88339b4f>] :dvb_usb:dvb_usb_generic_rw+0x2f/0x1a0 [83768.174580] PGD 0 [83768.174643] Oops: 0000 [1] SMP [83768.174723] CPU 0 [83768.174782] Modules linked in: nfsd auth_rpcgss exportfs nfs lockd nfs_acl sunrpc af_packet xt_length ipt_tos ipt_TOS xt_CLASSIFY sch_sfq sch_htb ipt_MASQUERADE ipt_REDIRECT xt_limit xt_state xt_tcpudp iptable_nat nf_nat nf_conntrack_ipv4 nf_conntrack iptable_mangle iptable_filter ip_tables x_tables xfs sbp2 parport_pc lp parport loop ftdi_sio usbserial evdev dvb_usb_dtt200u dvb_usb dvb_core i2c_core sky2 iTCO_wdt iTCO_vendor_support snd_hda_intel shpchp snd_pcm snd_timer snd_page_alloc snd_hwdep snd pci_hotplug soundcore ipv6 button intel_agp ext3 jbd mbcache sg sd_mod ata_generic pata_acpi ahci ata_piix libata scsi_mod ohci1394 ieee1394 ehci_hcd uhci_hcd usbcore e1000 thermal processor fan fbcon tileblit font bitblit softcursor fuse [83768.176968] Pid: 5732, comm: kdvb-fe-0 Not tainted 2.6.24-16-server #1 [83768.177009] RIP: 0010:[<ffffffff88339b4f>] [<ffffffff88339b4f>] :dvb_usb:dvb_usb_generic_rw+0x2f/0x1a0 [83768.177096] RSP: 0018:ffff810021939df0 EFLAGS: 00010286 [83768.177138] RAX: ffff81003bc7cc00 RBX: 0000000000000001 RCX: 0000000000000000 [83768.177181] RDX: 0000000000000001 RSI: ffff810021939e67 RDI: 0000000000000000 [83768.177223] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [83768.177267] R10: ffff810001009880 R11: 0000000000000001 R12: ffff81003c10b400 [83768.177311] R13: ffff81003c10b5b0 R14: ffff810021939ec0 R15: 0000000000000000 [83768.177354] FS: 0000000000000000(0000) GS:ffffffff805c3000(0000) knlGS:0000000000000000 [83768.177409] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b [83768.177449] CR2: 0000000000000120 CR3: 0000000000201000 CR4: 00000000000006e0 [83768.177491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [83768.177534] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [83768.177576] Process kdvb-fe-0 (pid: 5732, threadinfo ffff810021938000, task ffff81003bd1b7a0) [83768.177629] Stack: ffff81003e9b6828 0000000000000000 ffff8100378369f8 0000000000000000 [83768.177800] ffff81003bd1b7a0 ffff810037836d48 ffff81003bc7cc30 ffff81003c10b400 [83768.177943] ffff81003c10b5b0 ffff810021939ec0 ffff81003c10b5e0 ffffffff88342452 [83768.178054] Call Trace: [83768.178130] [<ffffffff88342452>] :dvb_usb_dtt200u:dtt200u_fe_init+0x22/0x30 [83768.178178] [<ffffffff88339f6a>] :dvb_usb:dvb_usb_fe_wakeup+0x3a/0x50 [83768.178229] [<ffffffff88325c41>] :dvb_core:dvb_frontend_init+0x21/0x70 [83768.178278] [<ffffffff8832746b>] :dvb_core:dvb_frontend_thread+0x8b/0x370 [83768.178329] [<ffffffff883273e0>] :dvb_core:dvb_frontend_thread+0x0/0x370 [83768.178382] [<ffffffff80253e3b>] kthread+0x4b/0x80 [83768.178427] [<ffffffff8020d198>] child_rip+0xa/0x12 [83768.178473] [<ffffffff80253df0>] kthread+0x0/0x80 [83768.178514] [<ffffffff8020d18e>] child_rip+0x0/0x12 [83768.178557] [83768.178594] [83768.178594] Code: 44 8b 87 20 01 00 00 49 89 f4 45 89 ce 45 85 c0 0f 84 ad 00 [83768.179167] RIP [<ffffffff88339b4f>] :dvb_usb:dvb_usb_generic_rw+0x2f/0x1a0 [83768.179234] RSP <ffff810021939df0> [83768.179271] CR2: 0000000000000120 [83768.179419] ---[ end trace dba8483163cb1700 ]--- Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> |
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|---|---|---|
| .. | ||
| b2c2 | ||
| bt8xx | ||
| dm1105 | ||
| dvb-core | ||
| dvb-usb | ||
| frontends | ||
| pluto2 | ||
| siano | ||
| ttpci | ||
| ttusb-budget | ||
| ttusb-dec | ||
| Kconfig | ||
| Makefile | ||