Subject: Re: [PATCH 3/3 V13] RO/NX protection for loadable kernel

From: matthieu castet <[email-masked]>
Date: Tue, 11 Jan 2011 23:42:47 +0100

Kees Cook a écrit :
> Hi,
> 
> I was just shown this[1] on Xen from an Ubuntu bug report[2].
> 
> [    1.230382] NX-protecting the kernel data: 3884k
> [    1.231002] BUG: unable to handle kernel paging request at c1782ae0
> ...
> [    1.231145] Call Trace:
> [    1.231152]  [<c0138481>] ? __change_page_attr+0x2c1/0x370
> [    1.231161]  [<c02163a1>] ? __purge_vmap_area_lazy+0xc1/0x180
> [    1.231169]  [<c013857c>] ? __change_page_attr_set_clr+0x4c/0xb0
> [    1.231176]  [<c0138838>] ? change_page_attr_set_clr+0x128/0x300
> [    1.231183]  [<c010798e>] ? __raw_callee_save_xen_restore_fl+0x6/0x8
> [    1.231192]  [<c0159ca1>] ? vprintk+0x171/0x3f0
> [    1.231198]  [<c0138bdf>] ? set_memory_nx+0x5f/0x70
> 
> 
> Does Xen have different size page table allocations or something weird?
> 
Note that this one isn't related to this one but to "Add NX protection for kernel data".

But have no idea how xen page table work.

Matthieu
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to [email-masked]
More majordomo info at  http://vger.kernel.org/majordomo-info.html