commit 49686cbbb3ebafe42e63868222f269d8053ead00 upstream.
nfs_idmap_legacy_upcall() is supposed to be called with 'aux' pointing
to a 'struct idmap', via the call to request_key_with_auxdata() in
nfs_idmap_request_key().
However it can also be reached via the request_key() system call in
which case 'aux' will be NULL, causing a NULL pointer dereference in
nfs_idmap_prepare_pipe_upcall(), assuming that the key description is
valid enough to get that far.
Fix this by making nfs_idmap_legacy_upcall() negate the key if no
auxdata is provided.
As usual, this bug was found by syzkaller. A simple reproducer using
the command-line keyctl program is:
keyctl request2 id_legacy uid:0 '' @s
Fixes: 57e62324e4 ("NFS: Store the legacy idmapper result in the keyring")
Reported-by: syzbot+5dfdbcf7b3eb5912abbb@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Trond Myklebust <trondmy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The idmap_init() and idmap_quit() functions only exist to call the
_keyring() version. Let's just call the keyring() functions directly.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Delete jump to a label on the next line, when that label is not
used elsewhere.
A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r@
identifier l;
@@
-if (...) goto l;
-l:
// </smpl>
Also drop the unnecessary ret variable.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
I added the nfs4 prefix to make it obvious that this file is built into
the NFS v4 module, and not the generic client.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
