Messages in this thread | | | Date | Thu, 17 Apr 2008 08:25:32 +0400 | From | "Cyrill Gorcunov" <> | Subject | Re: [patch 1/3] NFS: fix potential NULL pointer dereference |
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On Thu, Apr 17, 2008 at 12:40 AM, Trond Myklebust <trond.myklebust@fys.uio.no> wrote: > > On Thu, 2008-04-17 at 00:19 +0400, Cyrill Gorcunov wrote: > > Trond, I've just pointed the problem and its solution (which is seems > > to be a bit ugly, according to the rest nfs coding principle). So if > > you prefer to have such a check in 'walk_path' function - just say me > > that. You choose :) Thanks for comments > > > > > So? The defensive coding principle is that you perform validity checks > > > when the pointer is created. Otherwise, we could equally well have added > > > the NULL deref check to nfs4_path_walk()... > > No, your fix was correct, it was just incomplete. > > The point I was making above was that defensive programming means that > _all_ these validity/NULL pointer checks should really be done in > nfs4_validate_mount_data and nfs_validate_mount_data. We shouldn't rely > on checks in other parts of the code. > > In fact, as an example: it looks to me as if the lack of a > nfs_server.hostname, leads to a lack of nfs_client->cl_hostname, which > will eventually cause an Oops if you 'cat /proc/fs/nfsfs/servers', or if > you hit the printk in nfs_update_inode(), or various other dprintk()s. > > Trond > >
Thanks Trond, I'll remake it ASAP (but can't guarantie that it will be soon ;)
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