From 34061d6b76a41b1e43c19e1e50d98e5d77f77d4e Mon Sep 17 00:00:00 2001 From: Hyunchul Lee Date: Sat, 16 Oct 2021 08:39:54 +0900 Subject: [PATCH] ksmbd: validate OutputBufferLength of QUERY_DIR, QUERY_INFO, IOCTL requests Validate OutputBufferLength of QUERY_DIR, QUERY_INFO, IOCTL requests and check the free size of response buffer for these requests. Acked-by: Namjae Jeon Signed-off-by: Hyunchul Lee Signed-off-by: Steve French --- fs/ksmbd/smb2pdu.c | 68 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 52 insertions(+), 16 deletions(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 7999d8bc6892..e0f3a44e1599 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -3762,6 +3762,24 @@ static int verify_info_level(int info_level) return 0; } +static int smb2_calc_max_out_buf_len(struct ksmbd_work *work, + unsigned short hdr2_len, + unsigned int out_buf_len) +{ + int free_len; + + if (out_buf_len > work->conn->vals->max_trans_size) + return -EINVAL; + + free_len = (int)(work->response_sz - + (get_rfc1002_len(work->response_buf) + 4)) - + hdr2_len; + if (free_len < 0) + return -EINVAL; + + return min_t(int, out_buf_len, free_len); +} + int smb2_query_dir(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; @@ -3838,9 +3856,13 @@ int smb2_query_dir(struct ksmbd_work *work) memset(&d_info, 0, sizeof(struct ksmbd_dir_info)); d_info.wptr = (char *)rsp->Buffer; d_info.rptr = (char *)rsp->Buffer; - d_info.out_buf_len = (work->response_sz - (get_rfc1002_len(rsp_org) + 4)); - d_info.out_buf_len = min_t(int, d_info.out_buf_len, le32_to_cpu(req->OutputBufferLength)) - - sizeof(struct smb2_query_directory_rsp); + d_info.out_buf_len = + smb2_calc_max_out_buf_len(work, 8, + le32_to_cpu(req->OutputBufferLength)); + if (d_info.out_buf_len < 0) { + rc = -EINVAL; + goto err_out; + } d_info.flags = srch_flag; /* @@ -4074,12 +4096,11 @@ static int smb2_get_ea(struct ksmbd_work *work, struct ksmbd_file *fp, le32_to_cpu(req->Flags)); } - buf_free_len = work->response_sz - - (get_rfc1002_len(rsp_org) + 4) - - sizeof(struct smb2_query_info_rsp); - - if (le32_to_cpu(req->OutputBufferLength) < buf_free_len) - buf_free_len = le32_to_cpu(req->OutputBufferLength); + buf_free_len = + smb2_calc_max_out_buf_len(work, 8, + le32_to_cpu(req->OutputBufferLength)); + if (buf_free_len < 0) + return -EINVAL; rc = ksmbd_vfs_listxattr(path->dentry, &xattr_list); if (rc < 0) { @@ -4390,6 +4411,8 @@ static void get_file_stream_info(struct ksmbd_work *work, struct path *path = &fp->filp->f_path; ssize_t xattr_list_len; int nbytes = 0, streamlen, stream_name_len, next, idx = 0; + int buf_free_len; + struct smb2_query_info_req *req = ksmbd_req_buf_next(work); generic_fillattr(file_mnt_user_ns(fp->filp), file_inode(fp->filp), &stat); @@ -4403,6 +4426,12 @@ static void get_file_stream_info(struct ksmbd_work *work, goto out; } + buf_free_len = + smb2_calc_max_out_buf_len(work, 8, + le32_to_cpu(req->OutputBufferLength)); + if (buf_free_len < 0) + goto out; + while (idx < xattr_list_len) { stream_name = xattr_list + idx; streamlen = strlen(stream_name); @@ -4427,6 +4456,10 @@ static void get_file_stream_info(struct ksmbd_work *work, streamlen = snprintf(stream_buf, streamlen + 1, ":%s", &stream_name[XATTR_NAME_STREAM_LEN]); + next = sizeof(struct smb2_file_stream_info) + streamlen * 2; + if (next > buf_free_len) + break; + file_info = (struct smb2_file_stream_info *)&rsp->Buffer[nbytes]; streamlen = smbConvertToUTF16((__le16 *)file_info->StreamName, stream_buf, streamlen, @@ -4437,12 +4470,13 @@ static void get_file_stream_info(struct ksmbd_work *work, file_info->StreamSize = cpu_to_le64(stream_name_len); file_info->StreamAllocationSize = cpu_to_le64(stream_name_len); - next = sizeof(struct smb2_file_stream_info) + streamlen; nbytes += next; + buf_free_len -= next; file_info->NextEntryOffset = cpu_to_le32(next); } - if (!S_ISDIR(stat.mode)) { + if (!S_ISDIR(stat.mode) && + buf_free_len >= sizeof(struct smb2_file_stream_info) + 7 * 2) { file_info = (struct smb2_file_stream_info *) &rsp->Buffer[nbytes]; streamlen = smbConvertToUTF16((__le16 *)file_info->StreamName, @@ -7453,11 +7487,13 @@ int smb2_ioctl(struct ksmbd_work *work) } cnt_code = le32_to_cpu(req->CntCode); - out_buf_len = le32_to_cpu(req->MaxOutputResponse); - out_buf_len = - min_t(u32, work->response_sz - work->next_smb2_rsp_hdr_off - - (offsetof(struct smb2_ioctl_rsp, Buffer) - 4), - out_buf_len); + ret = smb2_calc_max_out_buf_len(work, 48, + le32_to_cpu(req->MaxOutputResponse)); + if (ret < 0) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + goto out; + } + out_buf_len = (unsigned int)ret; in_buf_len = le32_to_cpu(req->InputCount); switch (cnt_code) { -- 2.11.0