[PATCH 2/2] smb/server: fix posix state check for directory rename

From: ChenXiaoSong <[email protected]>

Reproducer:

  1. server: systemctl start ksmbd
  2. client: mount -t cifs //${server_ip}/export /mnt # without posix option
  3. client: mkdir /mnt/dir1/; touch /mnt/dir1/file
  4. client: tail -f /mnt/dir1/file # open file
  5. client: mv /mnt/dir1 /mnt/dir2
             rename succeeded, but it was expected to fail with "Permission denied"

See POSIX-FSA 2.1.3.1.

work->tcon->posix_extensions only records whether POSIX extensions were
negotiated on the connection. It does not indicate that the handles
were opened with POSIX create contexts.

Fixes: c841bd3d8dec ("ksmbd: deny renaming directory with open children")
Signed-off-by: ChenXiaoSong <[email protected]>
---
 fs/smb/server/vfs.c       | 3 +--
 fs/smb/server/vfs_cache.c | 2 ++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 34975e18528c..28940c7b5f83 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -721,8 +721,7 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, struct ksmbd_file *old_fp,
 	if (err)
 		goto out_drop_write;
 
-	if (!work->tcon->posix_extensions && d_is_dir(old_child) &&
-	    ksmbd_has_open_files(old_fp)) {
+	if (d_is_dir(old_child) && ksmbd_has_open_files(old_fp)) {
 		err = -EACCES;
 		goto out3;
 	}
diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c
index c66584ed23ab..eac9886eb6e3 100644
--- a/fs/smb/server/vfs_cache.c
+++ b/fs/smb/server/vfs_cache.c
@@ -1152,6 +1152,8 @@ bool ksmbd_has_open_files(struct ksmbd_file *old_fp)
 			continue;
 		if (fp_dentry == dentry)
 			continue;
+		if (old_fp->is_posix_ctxt && fp->is_posix_ctxt)
+			continue;
 		if (is_subdir(fp_dentry, dentry)) {
 			ret = true;
 			break;
-- 
2.54.0