From 074b07d94e0bb6ddce5690a9b7e2373088e8b33a Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Wed, 5 Jan 2022 14:15:03 -0500 Subject: [PATCH] nfsd: fix crash on COPY_NOTIFY with special stateid RTM says "If the special ONE stateid is passed to nfs4_preprocess_stateid_op(), it returns status=0 but does not set *cstid. nfsd4_copy_notify() depends on stid being set if status=0, and thus can crash if the client sends the right COPY_NOTIFY RPC." RFC 7862 says "The cna_src_stateid MUST refer to either open or locking states provided earlier by the server. If it is invalid, then the operation MUST fail." The RFC doesn't specify an error, and the choice doesn't matter much as this is clearly illegal client behavior, but bad_stateid seems reasonable. Simplest is just to guarantee that nfs4_preprocess_stateid_op, called with non-NULL cstid, errors out if it can't return a stateid. Reported-by: rtm@csail.mit.edu Fixes: 624322f1adc5 ("NFSD add COPY_NOTIFY operation") Signed-off-by: J. Bruce Fields Signed-off-by: Chuck Lever Reviewed-by: Olga Kornievskaia Tested-by: Olga Kornievskaia --- fs/nfsd/nfs4state.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index eb920f855969..72900b89cf84 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6058,7 +6058,11 @@ nfs4_preprocess_stateid_op(struct svc_rqst *rqstp, *nfp = NULL; if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) { - status = check_special_stateids(net, fhp, stateid, flags); + if (cstid) + status = nfserr_bad_stateid; + else + status = check_special_stateids(net, fhp, stateid, + flags); goto done; }