Messages in this thread Patch in this message | | | Date | Fri, 16 Apr 2004 17:16:28 -0700 | From | Chris Wright <> | Subject | Re: [CHECKER] Probable security holes in 2.6.5 |
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> [BUG] > /home/kash/linux/linux-2.6.5/drivers/scsi/3w-xxxx.c:780:tw_chrdev_ioctl: > ERROR:TAINT: 673:780:Passing unbounded user value "((1025 + > (*tw_ioctl).data_buffer_length) - 1)" as arg 2 to function > "copy_to_user", which uses it unsafely in model > [SOURCE_MODEL=(lib,copy_from_user,user,taintscalar)] > [SINK_MODEL=(lib,copy_to_user,user,trustingsink)] [PATH= "error != 0" > on line 674 is false] > } > > tw_ioctl = (TW_New_Ioctl *)cpu_addr; > > /* Now copy down the entire ioctl */ > Start ---> > error = copy_from_user(tw_ioctl, (void *)arg, data_buffer_length + > sizeof(TW_New_Ioctl) - 1); > > ... DELETED 101 lines ... > > retval = -ENOTTY; > goto out2; > } > > /* Now copy the response to userspace */ > Error ---> > error = copy_to_user((void *)arg, tw_ioctl, sizeof(TW_New_Ioctl) + > tw_ioctl->data_buffer_length - 1); > if (error == 0) > retval = 0; > out2:
The data_buffer_length was validated once, however upon second copy it's conceivable it could've been maliciously changed, so just use validated one. Patch below.
thanks, -chris -- Linux Security Modules http://lsm.immunix.org http://lsm.bkbits.net
===== drivers/scsi/3w-xxxx.c 1.40 vs edited ===== --- 1.40/drivers/scsi/3w-xxxx.c Tue Sep 23 08:00:30 2003 +++ edited/drivers/scsi/3w-xxxx.c Fri Apr 16 14:48:24 2004 @@ -683,7 +683,7 @@ break; case TW_OP_AEN_LISTEN: dprintk(KERN_WARNING "3w-xxxx: tw_chrdev_ioctl(): caught TW_AEN_LISTEN.\n"); - memset(tw_ioctl->data_buffer, 0, tw_ioctl->data_buffer_length); + memset(tw_ioctl->data_buffer, 0, data_buffer_length); spin_lock_irqsave(tw_dev->host->host_lock, flags); if (tw_dev->aen_head == tw_dev->aen_tail) { @@ -777,7 +777,7 @@ } /* Now copy the response to userspace */ - error = copy_to_user((void *)arg, tw_ioctl, sizeof(TW_New_Ioctl) + tw_ioctl->data_buffer_length - 1); + error = copy_to_user((void *)arg, tw_ioctl, sizeof(TW_New_Ioctl) + data_buffer_length - 1); if (error == 0) retval = 0; out2: - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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