[PATCH AUTOSEL 5.14 227/252] nfsd: fix crash on LOCKT on reexported NFSv3

Sasha Levin
2021-09-09T12:04:46Z

From: "J. Bruce Fields" <bfields@redhat.com>

[ Upstream commit 0bcc7ca40bd823193224e9f38bafbd8325aaf566 ]

Unlike other filesystems, NFSv3 tries to use fl_file in the GETLK case.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfsd/nfs4state.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index bebe86cce7c7..cde6b81aa22c 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7040,8 +7040,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
/*
* The NFSv4 spec allows a client to do a LOCKT without holding an OPEN,
* so we do a temporary open here just to get an open file to pass to
- * vfs_test_lock. (Arguably perhaps test_lock should be done with an
- * inode operation.)
+ * vfs_test_lock.
*/
static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
{
@@ -7056,7 +7055,9 @@ static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct
NFSD_MAY_READ));
if (err)
goto out;
+ lock->fl_file = nf->nf_file;
err = nfserrno(vfs_test_lock(nf->nf_file, lock));
+ lock->fl_file = NULL;
out:
fh_unlock(fhp);
nfsd_file_put(nf);
--
2.30.2