From: Steve French stfrench@microsoft.com
commit 3c3317daef0afa0cd541fc9c1bfd6ce8bbf1129a upstream.
When mounting with modefromsid mount option, it was possible to get the error on stat of a fifo or char or block device: "cannot stat <filename>: Operation not supported"
Special devices can be stored as reparse points by some servers (e.g. Windows NFS server and when using the SMB3.1.1 POSIX Extensions) but when the modefromsid mount option is used the client attempts to get the ACL for the file which requires opening with OPEN_REPARSE_POINT create option.
Signed-off-by: Steve French stfrench@microsoft.com CC: Stable stable@vger.kernel.org Reviewed-by: Ronnie Sahlberg lsahlber@redhat.com Reviewed-by: Shyam Prasad N sprasad@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/cifs/smb2ops.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -3072,7 +3072,12 @@ get_smb2_acl_by_path(struct cifs_sb_info oparms.tcon = tcon; oparms.desired_access = READ_CONTROL; oparms.disposition = FILE_OPEN; - oparms.create_options = cifs_create_options(cifs_sb, 0); + /* + * When querying an ACL, even if the file is a symlink we want to open + * the source not the target, and so the protocol requires that the + * client specify this flag when opening a reparse point + */ + oparms.create_options = cifs_create_options(cifs_sb, 0) | OPEN_REPARSE_POINT; oparms.fid = &fid; oparms.reconnect = false;