The patch number 9492 was added via Mauro Carvalho Chehab <[EMAIL PROTECTED]>
to http://linuxtv.org/hg/v4l-dvb master development tree.

Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel

If anyone has any objections, please let us know by sending a message to:
        [EMAIL PROTECTED]

------

From: Daniel J Blueman  <[EMAIL PROTECTED]>
unplug oops from dvb_frontend_init...


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 <[EMAIL PROTECTED]>


---

 linux/drivers/media/dvb/dvb-usb/dvb-usb-urb.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff -r 96770c51cf54 -r 749ce3d8e6c0 
linux/drivers/media/dvb/dvb-usb/dvb-usb-urb.c
--- a/linux/drivers/media/dvb/dvb-usb/dvb-usb-urb.c     Mon Oct 27 18:13:47 
2008 +0000
+++ b/linux/drivers/media/dvb/dvb-usb/dvb-usb-urb.c     Mon Jun 02 23:05:14 
2008 +0000
@@ -13,13 +13,13 @@ int dvb_usb_generic_rw(struct dvb_usb_de
 {
        int actlen,ret = -ENOMEM;
 
+       if (!d || wbuf == NULL || wlen == 0)
+               return -EINVAL;
+
        if (d->props.generic_bulk_ctrl_endpoint == 0) {
                err("endpoint for generic control not specified.");
                return -EINVAL;
        }
-
-       if (wbuf == NULL || wlen == 0)
-               return -EINVAL;
 
        if ((ret = mutex_lock_interruptible(&d->usb_mutex)))
                return ret;


---

Patch is available at: 
http://linuxtv.org/hg/v4l-dvb/rev/749ce3d8e6c04e147c7ee3352e863e48506713a9

_______________________________________________
linuxtv-commits mailing list
[email protected]
http://www.linuxtv.org/cgi-bin/mailman/listinfo/linuxtv-commits

Reply via email to