From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Tue, 29 Jan 2019 12:46:17 +1000
Subject: [PATCH] cifs: limit amount of data we request for xattrs to
CIFSMaxBufSize
Git-commit: c4627e66f73a28c5515b908c90c2bf7120086497
Patch-mainline: v5.0-rc5
References: bsc#1144333
minus the various headers and blobs that will be part of the reply.
or else we might trigger a session reconnect.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/smb2ops.c | 4 +++-
fs/cifs/smb2pdu.h | 15 +++++++++++++--
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 153238fc4fa9..6f96e2292856 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -866,7 +866,9 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon,
FILE_READ_EA,
FILE_FULL_EA_INFORMATION,
SMB2_O_INFO_FILE,
- SMB2_MAX_EA_BUF,
+ CIFSMaxBufSize -
+ MAX_SMB2_CREATE_RESPONSE_SIZE -
+ MAX_SMB2_CLOSE_RESPONSE_SIZE,
&rsp_iov, &buftype, cifs_sb);
if (rc) {
/*
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index e9cc6775df21..538e2299805f 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -85,6 +85,7 @@
#define NUMBER_OF_SMB2_COMMANDS 0x0013
/* 52 transform hdr + 64 hdr + 88 create rsp */
+#define SMB2_TRANSFORM_HEADER_SIZE 52
#define MAX_SMB2_HDR_SIZE 204
#define SMB2_PROTO_NUMBER cpu_to_le32(0x424d53fe)
@@ -648,6 +649,13 @@ struct smb2_create_req {
__u8 Buffer[0];
} __packed;
+/*
+ * Maximum size of a SMB2_CREATE response is 64 (smb2 header) +
+ * 88 (fixed part of create response) + 520 (path) + 150 (contexts) +
+ * 2 bytes of padding.
+ */
+#define MAX_SMB2_CREATE_RESPONSE_SIZE 824
+
struct smb2_create_rsp {
struct smb2_sync_hdr sync_hdr;
__le16 StructureSize; /* Must be 89 */
@@ -996,6 +1004,11 @@ struct smb2_close_req {
__u64 VolatileFileId; /* opaque endianness */
} __packed;
+/*
+ * Maximum size of a SMB2_CLOSE response is 64 (smb2 header) + 60 (data)
+ */
+#define MAX_SMB2_CLOSE_RESPONSE_SIZE 124
+
struct smb2_close_rsp {
struct smb2_sync_hdr sync_hdr;
__le16 StructureSize; /* 60 */
@@ -1398,8 +1411,6 @@ struct smb2_file_link_info { /* encoding of request for level 11 */
char FileName[0]; /* Name to be assigned to new link */
} __packed; /* level 11 Set */
-#define SMB2_MAX_EA_BUF 65536
-
struct smb2_file_full_ea_info { /* encoding of response for level 15 */
__le32 next_entry_offset;
__u8 flags;
--
2.16.4