6.10-stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown neilb@suse.de
[ Upstream commit 40927f3d0972bf86357a32a5749be71a551241b6 ]
It is not safe to dereference fl->c.flc_owner without first confirming fl->fl_lmops is the expected manager. nfsd4_deleg_getattr_conflict() tests fl_lmops but largely ignores the result and assumes that flc_owner is an nfs4_delegation anyway. This is wrong.
With this patch we restore the "!= &nfsd_lease_mng_ops" case to behave as it did before the change mentioned below. This is the same as the current code, but without any reference to a possible delegation.
Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation") Signed-off-by: NeilBrown neilb@suse.de Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfsd/nfs4state.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 07f2496850c4c..a366fb1c1b9b4 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -8859,7 +8859,15 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry, */ if (type == F_RDLCK) break; - goto break_lease; + + nfsd_stats_wdeleg_getattr_inc(nn); + spin_unlock(&ctx->flc_lock); + + status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ)); + if (status != nfserr_jukebox || + !nfsd_wait_for_delegreturn(rqstp, inode)) + return status; + return 0; } if (type == F_WRLCK) { struct nfs4_delegation *dp = fl->c.flc_owner; @@ -8868,7 +8876,6 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry, spin_unlock(&ctx->flc_lock); return 0; } -break_lease: nfsd_stats_wdeleg_getattr_inc(nn); dp = fl->c.flc_owner; refcount_inc(&dp->dl_stid.sc_count);