An offset from client could be a negative value, It could allows to write data outside the bounds of the allocated buffer. Note that this issue is coming when setting 'vfs objects = streams_xattr parameter' in ksmbd.conf. Cc: stable@xxxxxxxxxxxxxxx # v5.15+ Reported-by: Jordy Zomer <jordyzomer@xxxxxxxxxx> Signed-off-by: Jordy Zomer <jordyzomer@xxxxxxxxxx> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 7b6a3952f228..23879555880f 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -6882,6 +6882,8 @@ int smb2_write(struct ksmbd_work *work) } offset = le64_to_cpu(req->Offset); + if (offset < 0) + return -EINVAL; length = le32_to_cpu(req->Length); if (req->Channel == SMB2_CHANNEL_RDMA_V1 ||
