Messages in this thread | | | Date | Sat, 30 Apr 2005 10:53:06 -0400 | Subject | Re: [PATCH] cifs: handle termination of cifs oplockd kernel thread | From | "J. Bruce Fields" <> |
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On Sat, Apr 30, 2005 at 08:28:27AM -0500, Steve French wrote: > Miklos Szeredi wrote: > > >>>- network/userspace filesystems should be fine aswell > >>> > >>> > >>They should, but again I wonder if NFS with all it's complexity is > >>being careful enough with what it accepts from the server. > >> > >> > That is the fun of trying to get our network filesystems up to the > 20th century. There is at lot more work that has to be done here, but > it is gradually improving. At least for cifs but probably for NFSv4 > (and possibly AFS) it is possible for the client to validate that the > server is who it says it is, and both NFSv4 (actually the newer NFS > RPC) and CIFS of course allow packet signing which helps, not sure if > AFS allows packet signing.
None of this helps in the situation Miklos is considering, where the attacker is a user on the client doing the mount. So presumably the user gets to choose a server under his/her control, and all the authentication does is prove to the user that s/he got the right server, which doesn't protect the kernel at all.
The only defense is auditing the client code's handling of data it receives from the server.
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