Re: [BUG] NULL pointer dereference in dev_get_drvdata

From: Mauro Carvalho Chehab
Date: Tue Mar 29 2011 - 22:00:16 EST


Em 29-03-2011 22:28, Steven Rostedt escreveu:
> While running ktest.pl with randconfig tests on latest Linus (before
> 2.6.38-rc9 was released), several tests triggered a bug similar to this:
>
> Starting udev: udevd-work[880]: '/usr/bin/vmmouse_detect' unexpected exit with status 0x000b
> udevd-work[881]: '/usr/bin/vmmouse_detect' unexpected exit with status 0x000b
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
> IP: [<ffffffff818a6e9e>] dev_get_drvdata+0xe/0x39
> PGD 74dc7067 PUD 741ef067 PMD 0
> Oops: 0000 [#1] SMP
> last sysfs file: /sys/devices/virtual/net/teql0/address
> CPU 1
> Modules linked in: ide_pci_generic iTCO_wdt iTCO_vendor_support ide_core
>
> Pid: 994, comm: v4l_id Not tainted 2.6.38-test-09043-gc585015 #1 /DG965MQ
> RIP: 0010:[<ffffffff818a6e9e>] [<ffffffff818a6e9e>] dev_get_drvdata+0xe/0x39
> RSP: 0018:ffff8800743dbb68 EFLAGS: 00010202
> RAX: 0000000000000000 RBX: ffff8800743dbba0 RCX: 0000000000000000
> RDX: ffffffff8408b740 RSI: 0000000000000000 RDI: 0000000000000010
> RBP: ffff8800743dbb68 R08: ffff8800743dbb98 R09: 00000000000023e7
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: ffff88007784f888 R14: ffff880076f82140 R15: 0000000000000000
> FS: 00007f4059724700(0000) GS:ffff88007e280000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000018 CR3: 00000000742bb000 CR4: 00000000000006e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process v4l_id (pid: 994, threadinfo ffff8800743da000, task ffff880074dac420)
> Stack:
> ffff8800743dbb88 ffffffff818e4129 ffff880074dac420 ffffffff8408b740
> ffff8800743dbbc8 ffffffff818e1865 2222222222222222 2222222222222222
> ffff88007784f000 0000000000000000 ffff88007784f888 ffff880076f82140
> Call Trace:
> [<ffffffff818e4129>] st_kim_ref+0x2c/0x42
> [<ffffffff818e1865>] st_register+0x29/0x444
> [<ffffffff81dc6415>] fmc_prepare+0x75/0x382
> [<ffffffff81dc9109>] fm_v4l2_fops_open+0x5a/0xce
> [<ffffffff81d40bab>] v4l2_open+0x180/0x212
> [<ffffffff811c6fc5>] chrdev_open+0x1c5/0x204
> [<ffffffff811c6e00>] ? cdev_put+0x45/0x45
> [<ffffffff811bf61e>] __dentry_open+0x2a1/0x467
> [<ffffffff811c0bd8>] nameidata_to_filp+0x75/0x83
> [<ffffffff811d2c5f>] do_last+0x716/0x902
> [<ffffffff811d02e7>] ? path_init+0x1fd/0x46f
> [<ffffffff811d3d07>] path_openat+0x102/0x4cd
> [<ffffffff811d413d>] do_filp_open+0x6b/0xb5
> [<ffffffff822671ab>] ? _raw_spin_unlock+0x40/0x4c
> [<ffffffff811e387e>] ? alloc_fd+0x165/0x17e
> [<ffffffff811c0c7f>] do_sys_open+0x99/0x16a
> [<ffffffff811c0d77>] sys_open+0x27/0x30
> [<ffffffff82270a82>] system_call_fastpath+0x16/0x1b
> Code: 90 55 48 89 e5 0f 1f 44 00 00 48 ff 05 ac 70 5d 02 f0 ff 07 48 ff 05 aa 70 5d 02 c9 c3 55 48 89 e5 0f 1f 44 00 00 48 85 ff 74 20
> 8b 47 08 48 ff 05 97 70 5d 02 48 85 c0 74 10 48 8b 80 b8 00
> RIP [<ffffffff818a6e9e>] dev_get_drvdata+0xe/0x39
> RSP <ffff8800743dbb68>
> CR2: 0000000000000018
>
> As not all configs triggered this, but when a config did trigger it, it
> was consistent. I ran the "config-bisect" of ktest.pl to find the dirty
> culprit, and it came up with:
>
> ***************************************
> Found bad config: CONFIG_RADIO_WL128X
> ***************************************
>
> When I removed the config, sure enough, the bug goes away. I added it
> back in and the bug re-appeared.
>
> The .config can be downloaded here:
> http://rostedt.homelinux.com/private/mxtest-boot-randconfig-fail-20110228232103/config
>
> and the full dmesg here:
> http://rostedt.homelinux.com/private/mxtest-boot-randconfig-fail-20110228232103/dmesg
>
> -- Steve

Thanks for reporting it.

There were a change at ST interface, affecting this new driver.

I'm updating the fix today to -next:

commit f3149c7d9d989796306c6e65afbf4e89b3f81436
Author: Manjunatha Halli <manjunatha_halli@xxxxxx>
Date: Wed Mar 23 07:44:30 2011 -0300

[media] radio: wl128x: Update registration process with ST

As underlying ST driver registration API's have changed with
latest 2.6.38-rc8 kernel this patch will update the FM driver
accordingly.

Signed-off-by: Manjunatha Halli <manjunatha_halli@xxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>

It is already on my tree:
ssh://master.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-next.git

It should be available soon at kernel.org mirrors.

Could you please test it?

Thanks!
Mauro

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