Ondrej Mosnacek 8e29eebe4c lsm: fix default return value for inode_getsecctx
commit b36995b8609a5a8fe5cf259a1ee768fcaed919f8 upstream.

-EOPNOTSUPP is the return value that implements a "no-op" hook, not 0.

Without this fix having only the BPF LSM enabled (with no programs
attached) can cause uninitialized variable reads in
nfsd4_encode_fattr(), because the BPF hook returns 0 without touching
the 'ctxlen' variable and the corresponding 'contextlen' variable in
nfsd4_encode_fattr() remains uninitialized, yet being treated as valid
based on the 0 return value.

Cc: stable@vger.kernel.org
Fixes: 98e828a065 ("security: Refactor declaration of LSM hooks")
Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:55:00 +00:00
2023-04-05 11:23:43 +02:00
2023-06-21 15:45:38 +02:00
2023-11-20 11:06:57 +01:00

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