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| author | J. Bruce Fields <bfields@redhat.com> | 2019-12-06 16:07:32 -0500 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2019-12-09 11:44:07 -0500 |
| commit | d781e3df710745fbbaee4eb07fd5b64331a1b175 (patch) | |
| tree | b9b95fce122ce1041e0aa379944d3c2eb6912f9b | |
| parent | 2e577f0faca4640348c398cb85d60a1eedac4b1e (diff) | |
| download | linux-d781e3df710745fbbaee4eb07fd5b64331a1b175.tar.bz2 | |
nfsd4: avoid NULL deference on strange COPY compounds
With cross-server COPY we've introduced the possibility that the current
or saved filehandle might not have fh_dentry/fh_export filled in, but we
missed a place that assumed it was. I think this could be triggered by
a compound like:
PUTFH(foreign filehandle)
GETATTR
SAVEFH
COPY
First, check_if_stalefh_allowed sets no_verify on the first (PUTFH) op.
Then op_func = nfsd4_putfh runs and leaves current_fh->fh_export NULL.
need_wrongsec_check returns true, since this PUTFH has OP_IS_PUTFH_LIKE
set and GETATTR does not have OP_HANDLES_WRONGSEC set.
We should probably also consider tightening the checks in
check_if_stalefh_allowed and double-checking that we don't assume the
filehandle is verified elsewhere in the compound. But I think this
fixes the immediate issue.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 4e48f1cccab3 "NFSD: allow inter server COPY to have... "
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | fs/nfsd/nfs4proc.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index d33c39c18cdd..30c75b961d68 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2368,7 +2368,8 @@ nfsd4_proc_compound(struct svc_rqst *rqstp) if (op->opdesc->op_flags & OP_CLEAR_STATEID) clear_current_stateid(cstate); - if (need_wrongsec_check(rqstp)) + if (current_fh->fh_export && + need_wrongsec_check(rqstp)) op->status = check_nfsd_access(current_fh->fh_export, rqstp); } encode_op: |