From c0cd3fc6824122014da2b3b0cb7ddeaa2946ec8e Mon Sep 17 00:00:00 2001 From: Aleksandr Khromov Date: Mon, 24 Aug 2026 21:23:32 +0900 Subject: ksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATION smb2_get_info_filesystem() reports 48 bytes for FS_CONTROL_INFORMATION, that is the whole of struct smb2_fs_control_info, but never assigns FileSystemControlFlags. Those four bytes go to the client as they are found in the response buffer. The buffer is zeroed on allocation, so a standalone request leaks nothing. A compound request can leak: the offset of the next response is advanced by the length pinned for the previous one, so a reply that was written into the buffer and then dropped in favour of the short error response of smb2_set_err_rsp() stays there, and the next reply is laid over it with only the header cleared. ksmbd does not implement quota tracking, so report no control flags. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: Aleksandr Khromov Signed-off-by: Namjae Jeon --- fs/smb/server/smb2pdu.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 486cd745dd21..2fbd9010513e 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -7500,6 +7500,7 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work, info->FreeSpaceStopFiltering = 0; info->DefaultQuotaThreshold = cpu_to_le64(SMB2_NO_FID); info->DefaultQuotaLimit = cpu_to_le64(SMB2_NO_FID); + info->FileSystemControlFlags = 0; info->Padding = 0; rsp->OutputBufferLength = cpu_to_le32(48); fixed_len = 48; -- cgit v1.2.3