[PATCH 5.15 173/917] ksmbd: set unique value to volume serial field in FS_VOLUME_INFORMATION

Greg Kroah-Hartman
2021-11-16T01:05:02Z

From: Namjae Jeon <linkinjeon@kernel.org>

commit 5d2f0b1083eb158bdff01dd557e2c25046c0a7d2 upstream.

Steve French reported ksmbd set fixed value to volume serial field in
FS_VOLUME_INFORMATION. Volume serial value needs to be set to a unique
value for client fscache. This patch set crc value that is generated
with share name, path name and netbios name to volume serial.

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org # v5.15
Reported-by: Steve French <smfrench@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ksmbd/Kconfig | 1 +
fs/ksmbd/server.c | 1 +
fs/ksmbd/smb2pdu.c | 9 ++++++++-
3 files changed, 10 insertions(+), 1 deletion(-)

--- a/fs/ksmbd/Kconfig
+++ b/fs/ksmbd/Kconfig
@@ -19,6 +19,7 @@ config SMB_SERVER
select CRYPTO_GCM
select ASN1
select OID_REGISTRY
+ select CRC32
default n
help
Choose Y here if you want to allow SMB3 compliant clients
--- a/fs/ksmbd/server.c
+++ b/fs/ksmbd/server.c
@@ -632,5 +632,6 @@ MODULE_SOFTDEP("pre: sha512");
MODULE_SOFTDEP("pre: aead2");
MODULE_SOFTDEP("pre: ccm");
MODULE_SOFTDEP("pre: gcm");
+MODULE_SOFTDEP("pre: crc32");
module_init(ksmbd_server_init)
module_exit(ksmbd_server_exit)
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -4891,11 +4891,18 @@ static int smb2_get_info_filesystem(stru
{
struct filesystem_vol_info *info;
size_t sz;
+ unsigned int serial_crc = 0;

info = (struct filesystem_vol_info *)(rsp->Buffer);
info->VolumeCreationTime = 0;
+ serial_crc = crc32_le(serial_crc, share->name,
+ strlen(share->name));
+ serial_crc = crc32_le(serial_crc, share->path,
+ strlen(share->path));
+ serial_crc = crc32_le(serial_crc, ksmbd_netbios_name(),
+ strlen(ksmbd_netbios_name()));
/* Taking dummy value of serial number*/
- info->SerialNumber = cpu_to_le32(0xbc3ac512);
+ info->SerialNumber = cpu_to_le32(serial_crc);
len = smbConvertToUTF16((__le16 *)info->VolumeLabel,
share->name, PATH_MAX,
conn->local_nls, 0);