Messages in this thread | | | Date | Thu, 17 Feb 2011 20:36:47 -0800 (PST) | Subject | Re: BUG: Bad page map in process udevd (anon_vma: (null)) in 2.6.38-rc4 | From | David Miller <> |
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From: Linus Torvalds <torvalds@linux-foundation.org> Date: Thu, 17 Feb 2011 20:30:42 -0800
> On Thu, Feb 17, 2011 at 7:16 PM, Eric W. Biederman > <ebiederm@xmission.com> wrote: >> BUG: unable to handle kernel paging request at ffff8801adf8d760 >> IP: [<ffffffff8140c7ca>] unregister_netdevice_queue+0x3a/0xb0 > > Yup. That's the "list_move()". The disassembly is exactly what I'd > expect from __list_del(): > > 16: 48 8b 93 a0 00 00 00 mov 0xa0(%rbx),%rdx > 1d: 48 8b 83 a8 00 00 00 mov 0xa8(%rbx),%rax > 24: 48 8d bb a0 00 00 00 lea 0xa0(%rbx),%rdi > 2b:* 48 89 42 08 mov %rax,0x8(%rdx) <-- trapping instruction > 2f: 48 89 10 mov %rdx,(%rax) > > So I think we can consider this confirmed: it really is the stale > queue left over on the stack (introduced by commit 443457242beb). With > CONFIG_DEBUG_PAGEALLOC, you get a page fault when it tries to update > the now stale pointers. > > The patch from Eric Dumazet (which adds a few more cases to my patch > and hopefully catches them all) almost certainly fixes this rather > nasty memory corruption.
Eric D., please get a final version of the fix posted to netdev and I'll make sure it slithers it's way to Linus's tree :-)
Thanks!
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