[PATCH 6.1 167/215] lockd: ensure we use the correct file descriptor when unlocking

Greg Kroah-Hartman
2024-03-04T21:50:13Z

From: Jeff Layton <jlayton@kernel.org>

[ Upstream commit 69efce009f7df888e1fede3cb2913690eb829f52 ]

Shared locks are set on O_RDONLY descriptors and exclusive locks are set
on O_WRONLY ones. nlmsvc_unlock however calls vfs_lock_file twice, once
for each descriptor, but it doesn't reset fl_file. Ensure that it does.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/lockd/svclock.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -659,11 +659,13 @@ nlmsvc_unlock(struct net *net, struct nl
nlmsvc_cancel_blocked(net, file, lock);

lock->fl.fl_type = F_UNLCK;
- if (file->f_file[O_RDONLY])
- error = vfs_lock_file(file->f_file[O_RDONLY], F_SETLK,
+ lock->fl.fl_file = file->f_file[O_RDONLY];
+ if (lock->fl.fl_file)
+ error = vfs_lock_file(lock->fl.fl_file, F_SETLK,
&lock->fl, NULL);
- if (file->f_file[O_WRONLY])
- error = vfs_lock_file(file->f_file[O_WRONLY], F_SETLK,
+ lock->fl.fl_file = file->f_file[O_WRONLY];
+ if (lock->fl.fl_file)
+ error |= vfs_lock_file(lock->fl.fl_file, F_SETLK,
&lock->fl, NULL);

return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;