On Tue, 22 Nov 2011, Norbert Preining wrote: > Hi all, > > (please Cc) > > running current git kernel (commit f8f5ed7c9) I see this Oops > when connecting an USB stick: > [ 65.428179] usb 2-1: new high-speed USB device number 2 using ehci_hcd > [ 65.563400] usb 2-1: New USB device found, idVendor=1687, idProduct=3252 > [ 65.565004] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > [ 65.566519] usb 2-1: Product: USB2.0 FlashDisk > [ 65.567998] usb 2-1: Manufacturer: Kingmax > [ 65.569460] usb 2-1: SerialNumber: AA04012700039580 > [ 66.045924] Initializing USB Mass Storage driver... > [ 66.047551] scsi6 : usb-storage 2-1:1.0 > [ 66.049146] usbcore: registered new interface driver usb-storage > [ 66.050606] USB Mass Storage support registered. > [ 67.808567] scsi 6:0:0:0: Direct-Access Kingmax USB2.0 FlashDisk 1100 PQ: 0 ANSI: 0 CCS > [ 67.813844] sd 6:0:0:0: Attached scsi generic sg2 type 0 > [ 67.821873] sd 6:0:0:0: [sdb] 7471104 512-byte logical blocks: (3.82 GB/3.56 GiB) > [ 67.827475] sd 6:0:0:0: [sdb] Write Protect is off > [ 67.832164] sd 6:0:0:0: [sdb] Mode Sense: 43 00 00 00 > [ 67.837710] sd 6:0:0:0: [sdb] No Caching mode page present > [ 67.842228] sd 6:0:0:0: [sdb] Assuming drive cache: write through > [ 67.848325] sd 6:0:0:0: [sdb] No Caching mode page present > [ 67.849838] sd 6:0:0:0: [sdb] Assuming drive cache: write through > [ 67.852328] BUG: unable to handle kernel NULL pointer dereference at 00000000000002d9 > [ 67.853898] IP: [<ffffffffa0249e6b>] last_sector_hacks.part.2+0x72/0xe0 [usb_storage] This is odd. I've never seen a problem in that routine before. What is "last_sector_hacks.part.2"? In my kernel source tree there is a last_sector_hacks() function in drivers/usb/storage/transport.c, but what does the ".part.2" refer to? I can't see many places in the routine which might dereference a NULL pointer. About the only possibility is the line: disk = srb->request->rq_disk; This would get an error if srb->request was NULL. Can you add a little debugging code to test for that case? If it is NULL, just "goto done". Alan Stern -- 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
