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| author | Jiri Slaby <jslaby@suse.cz> | 2011-02-15 15:55:07 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-17 10:30:25 -0800 |
| commit | 38237fd2be9421c104f84cc35665097bdce89013 (patch) | |
| tree | 5f8a8906662f9d0a398db53332d8f2204878b0c6 | |
| parent | 637d11bfb814637ec7b81e878db3ffea6408a89a (diff) | |
| download | blackbird-obmc-linux-38237fd2be9421c104f84cc35665097bdce89013.tar.gz blackbird-obmc-linux-38237fd2be9421c104f84cc35665097bdce89013.zip | |
USB: serial/usb_wwan, fix tty NULL dereference
tty_port_tty_get may return without any problems NULL. Handle this
case and do not oops in usb_wwan_indat_callback by dereferencing it.
The oops:
Unable to handle kernel paging request for data at address 0x000000d8
Faulting instruction address: 0xc0175b3c
Oops: Kernel access of bad area, sig: 11 [#1]
PowerPC 40x Platform
last sysfs file:
/sys/devices/pci0000:00/0000:00:00.0/0000:01:00.0/0000:02:09.2/usb1/idVendor
Modules linked in:
NIP: c0175b3c LR: c0175e7c CTR: c0215c90
REGS: c77f7d50 TRAP: 0300 Not tainted (2.6.37-rc5)
MSR: 00021030 <ME,CE,IR,DR> CR: 88482028 XER: 2000005f
DEAR: 000000d8, ESR: 00000000
TASK = c7141b90[1149] 'wvdial' THREAD: c2750000
GPR00: 00021030 c77f7e00 c7141b90 00000000 0000000e 00000000 0000000e c0410680
GPR08: c683db00 00000000 00000001 c03c81f8 88482028 10073ef4 ffffffb9 ffffff94
GPR16: 00000000 fde036c0 00200200 00100100 00000001 ffffff8d c34fabcc 00000000
GPR24: c71120d4 00000000 00000000 0000000e 00021030 00000000 00000000 0000000e
NIP [c0175b3c] tty_buffer_request_room+0x2c/0x194
LR [c0175e7c] tty_insert_flip_string_fixed_flag+0x3c/0xb0
Call Trace:
[c77f7e00] [00000003] 0x3 (unreliable)
[c77f7e30] [c0175e7c] tty_insert_flip_string_fixed_flag+0x3c/0xb0
[c77f7e60] [c0215df4] usb_wwan_indat_callback+0x164/0x170
...
References: https://bugzilla.kernel.org/show_bug.cgi?id=24582
Cc: Amit Shah <amitshah@gmx.net>
Cc: baoyb <baoyb@avit.org.cn>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/serial/usb_wwan.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c index b004b2a485c3..9c014e2ecd68 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -295,12 +295,15 @@ static void usb_wwan_indat_callback(struct urb *urb) __func__, status, endpoint); } else { tty = tty_port_tty_get(&port->port); - if (urb->actual_length) { - tty_insert_flip_string(tty, data, urb->actual_length); - tty_flip_buffer_push(tty); - } else - dbg("%s: empty read urb received", __func__); - tty_kref_put(tty); + if (tty) { + if (urb->actual_length) { + tty_insert_flip_string(tty, data, + urb->actual_length); + tty_flip_buffer_push(tty); + } else + dbg("%s: empty read urb received", __func__); + tty_kref_put(tty); + } /* Resubmit urb so we continue receiving */ if (status != -ESHUTDOWN) { |
