5.4-stable review patch. If anyone has any objections, please let me know.
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From: Pali Rohár pali@kernel.org
[ Upstream commit a3e771afbb3bce91c8296828304903e7348003fe ]
For TRANS2 QUERY_PATH_INFO request when the path does not exist, the Windows NT SMB server returns error response STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile without the SMBFLG_RESPONSE flag set. Similarly it returns STATUS_DELETE_PENDING when the file is being deleted. And looks like that any error response from TRANS2 QUERY_PATH_INFO does not have SMBFLG_RESPONSE flag set.
So relax check in check_smb_hdr() for detecting if the packet is response for this special case.
This change fixes stat() operation against Windows NT SMB servers and also all operations which depends on -ENOENT result from stat like creat() or mkdir().
Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/misc.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index db1fcdedf289a..af9752535dbab 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -306,6 +306,14 @@ check_smb_hdr(struct smb_hdr *smb) if (smb->Command == SMB_COM_LOCKING_ANDX) return 0;
+ /* + * Windows NT server returns error resposne (e.g. STATUS_DELETE_PENDING + * or STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile or any other) + * for some TRANS2 requests without the RESPONSE flag set in header. + */ + if (smb->Command == SMB_COM_TRANSACTION2 && smb->Status.CifsError != 0) + return 0; + cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", get_mid(smb)); return 1;