Re: NULL pointer deref at wext ioctl (Re: [PATCH] compat-2.6: adding ethtool.h to compat-2.6.31.h)

[Johannes Berg <johannes@sipsolutions.net>]

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On Wed, 2009-10-07 at 20:28 +0100, Hin-Tak Leung wrote:
> On Wed, Oct 7, 2009 at 8:16 PM, Hin-Tak Leung <hintak.leung@gmail.com> wrote:
> 
> > It is probably just a transient problem with recent activities - I had
> > a NULL pointer deref from loading rtl8187 of compat-wireless
> > v2.6.32-rc3-39563-g98c2609 -
> >
> > BUG: unable to handle kernel NULL pointer dereference at 000000000000003d
> > IP: [<ffffffff8147822c>] wext_ioctl_dispatch+0xd9/0x180
> > PGD 61c2b067 PUD 6246f067 PMD 0
> > Oops: 0000 [#1] SMP
> > ...
> > Call Trace:
> >  [<ffffffff814783f5>] wext_handle_ioctl+0x4d/0x98
> >  [<ffffffff813e53a5>] dev_ioctl+0x625/0x662
> >  [<ffffffff813cfa45>] sock_ioctl+0x225/0x248
> >  [<ffffffff811237a3>] vfs_ioctl+0x31/0xaa
> >  [<ffffffff811e1801>] ? security_d_instantiate+0x37/0x4d
> >  [<ffffffff81123c88>] do_vfs_ioctl+0x46c/0x4c3
> >  [<ffffffff81123d44>] sys_ioctl+0x65/0x9c
> >  [<ffffffff81012082>] system_call_fastpath+0x16/0x1b
> >
> > I'm sure whatever changes made this happen will go away soon, so I'll
> > just re-try in a few days... but if anybody knows what commit causes
> > this (and what fixes it!), I'd like to know.
> >
> 
> Hiya, It looks like I last used compat-wireless successfully was on
> 25th (I am not saying it breaks after - I just haven't tried until
> yesterday, possibly), and most of the recent changes are per-driver,
> but there is a big code drop from Johannes dated 27th on 'wext:
> refactor' . Changes from that or dependent changes?

Probably -- but I don't see this problem on stock kernel and I'm not
sure what could be causing it for compat-wireless.

This will be the old copy of wext_ioctl_dispatch. It'd certainly help to
get disassembly/the source line of the oops.

johannes

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