6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: NeilBrown <neilb@xxxxxxx>
[ 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@xxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
--
2.43.0
