On (Tue) 15 Feb 2011 [20:14:50], Sergei Shtylyov wrote: > Hello. > > Jiri Slaby wrote: > > >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. Thanks for looking at this! > >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@xxxxxxx> > >Cc: baoyb <baoyb@xxxxxxxxxxx> > >Cc: Greg Kroah-Hartman <gregkh@xxxxxxx> > >Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> > >--- > > 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 b004b2a..9c014e2 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__); > > Should be {} on the *else* branch too, according to Documentation/CodingStyle... If you're fixing that, might as well return in the 'if' above so that this entire 'else' block becomes non-indented. Amit -- http://log.amitshah.net/ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
