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authorJ. Bruce Fields <bfields@redhat.com>2019-12-06 16:07:32 -0500
committerJ. Bruce Fields <bfields@redhat.com>2019-12-09 11:44:07 -0500
commitd781e3df710745fbbaee4eb07fd5b64331a1b175 (patch)
treeb9b95fce122ce1041e0aa379944d3c2eb6912f9b /fs/nfsd
parent2e577f0faca4640348c398cb85d60a1eedac4b1e (diff)
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>
Diffstat (limited to 'fs/nfsd')
-rw-r--r--fs/nfsd/nfs4proc.c3
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: