Re: [PATCH v2 3/7] ksmbd: add validation in smb2_ioctl

Namjae Jeon
2021-09-26T03:26:33Z

2021-09-25 22:16 GMT+09:00, Namjae Jeon <linkinjeon@kernel.org>:
> Add validation for request/response buffer size check in smb2_ioctl and
> fsctl_copychunk() take copychunk_ioctl_req pointer and the other arguments
> instead of smb2_ioctl_req structure and remove an unused smb2_ioctl_req
> argument of fsctl_validate_negotiate_info.
>
> Cc: Tom Talpey <tom@talpey.com>
> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
> Cc: Ralph Böhme <slow@samba.org>
> Cc: Steve French <smfrench@gmail.com>
> Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
> Acked-by: Hyunchul Lee <hyc.lee@gmail.com>
> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
> ---
> fs/ksmbd/smb2pdu.c | 96 +++++++++++++++++++++++++++++++++++-----------
> fs/ksmbd/vfs.c | 2 +-
> fs/ksmbd/vfs.h | 2 +-
> 3 files changed, 75 insertions(+), 25 deletions(-)
>
> diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
> index 2f7ce7f28eb6..c54e9e35fbc5 100644
> --- a/fs/ksmbd/smb2pdu.c
> +++ b/fs/ksmbd/smb2pdu.c
> @@ -6909,24 +6909,26 @@ int smb2_lock(struct ksmbd_work *work)
> return err;
> }
>
> -static int fsctl_copychunk(struct ksmbd_work *work, struct smb2_ioctl_req
> *req,
> +static int fsctl_copychunk(struct ksmbd_work *work,
> + struct copychunk_ioctl_req *ci_req,
> + unsigned int cnt_code,
> + unsigned int input_count,
> + unsigned long long volatile_id,
> + unsigned long long persistent_id,
> struct smb2_ioctl_rsp *rsp)
> {
> - struct copychunk_ioctl_req *ci_req;
> struct copychunk_ioctl_rsp *ci_rsp;
> struct ksmbd_file *src_fp = NULL, *dst_fp = NULL;
> struct srv_copychunk *chunks;
> unsigned int i, chunk_count, chunk_count_written = 0;
> unsigned int chunk_size_written = 0;
> loff_t total_size_written = 0;
> - int ret, cnt_code;
> + int ret = 0;
>
> - cnt_code = le32_to_cpu(req->CntCode);
> - ci_req = (struct copychunk_ioctl_req *)&req->Buffer[0];
> ci_rsp = (struct copychunk_ioctl_rsp *)&rsp->Buffer[0];
>
> - rsp->VolatileFileId = req->VolatileFileId;
> - rsp->PersistentFileId = req->PersistentFileId;
> + rsp->VolatileFileId = cpu_to_le64(volatile_id);
> + rsp->PersistentFileId = cpu_to_le64(persistent_id);
> ci_rsp->ChunksWritten =
> cpu_to_le32(ksmbd_server_side_copy_max_chunk_count());
> ci_rsp->ChunkBytesWritten =
> @@ -6936,12 +6938,13 @@ static int fsctl_copychunk(struct ksmbd_work *work,
> struct smb2_ioctl_req *req,
>
> chunks = (struct srv_copychunk *)&ci_req->Chunks[0];
> chunk_count = le32_to_cpu(ci_req->ChunkCount);
> + if (chunk_count == 0)
> + goto out;
> total_size_written = 0;
>
> /* verify the SRV_COPYCHUNK_COPY packet */
> if (chunk_count > ksmbd_server_side_copy_max_chunk_count() ||
> - le32_to_cpu(req->InputCount) <
> - offsetof(struct copychunk_ioctl_req, Chunks) +
> + input_count < offsetof(struct copychunk_ioctl_req, Chunks) +
> chunk_count * sizeof(struct srv_copychunk)) {
> rsp->hdr.Status = STATUS_INVALID_PARAMETER;
> return -EINVAL;
> @@ -6962,9 +6965,7 @@ static int fsctl_copychunk(struct ksmbd_work *work,
> struct smb2_ioctl_req *req,
>
> src_fp = ksmbd_lookup_foreign_fd(work,
> le64_to_cpu(ci_req->ResumeKey[0]));
> - dst_fp = ksmbd_lookup_fd_slow(work,
> - le64_to_cpu(req->VolatileFileId),
> - le64_to_cpu(req->PersistentFileId));
> + dst_fp = ksmbd_lookup_fd_slow(work, volatile_id, persistent_id);
> ret = -EINVAL;
> if (!src_fp ||
> src_fp->persistent_id != le64_to_cpu(ci_req->ResumeKey[1])) {
> @@ -7039,8 +7040,8 @@ static __be32 idev_ipv4_address(struct in_device
> *idev)
> }
>
> static int fsctl_query_iface_info_ioctl(struct ksmbd_conn *conn,
> - struct smb2_ioctl_req *req,
> - struct smb2_ioctl_rsp *rsp)
> + struct smb2_ioctl_rsp *rsp,
> + int out_buf_len)
> {
> struct network_interface_info_ioctl_rsp *nii_rsp = NULL;
> int nbytes = 0;
> @@ -7123,6 +7124,8 @@ static int fsctl_query_iface_info_ioctl(struct
> ksmbd_conn *conn,
> sockaddr_storage->addr6.ScopeId = 0;
> }
>
> + if (out_buf_len - nbytes < sizeof(struct
> network_interface_info_ioctl_rsp))
> + break;
Moved this check to the top of loop to avoid unneeded behavior when
out_buf_len is smaller than network_interface_info_ioctl_rsp.

> nbytes += sizeof(struct network_interface_info_ioctl_rsp);
> }
> rtnl_unlock();
> @@ -7143,11 +7146,16 @@ static int fsctl_query_iface_info_ioctl(struct
> ksmbd_conn *conn,
>
> static int fsctl_validate_negotiate_info(struct ksmbd_conn *conn,
> struct validate_negotiate_info_req *neg_req,
> - struct validate_negotiate_info_rsp *neg_rsp)
> + struct validate_negotiate_info_rsp *neg_rsp,
> + unsigned int in_buf_len)
> {
> int ret = 0;
> int dialect;
>
> + if (in_buf_len < sizeof(struct validate_negotiate_info_req) +
> + le16_to_cpu(neg_req->DialectCount) * sizeof(__le16))
> + return -EINVAL;
> +
> dialect = ksmbd_lookup_dialect_by_id(neg_req->Dialects,
> neg_req->DialectCount);
> if (dialect == BAD_PROT_ID || dialect != conn->dialect) {
> @@ -7181,7 +7189,7 @@ static int fsctl_validate_negotiate_info(struct
> ksmbd_conn *conn,
> static int fsctl_query_allocated_ranges(struct ksmbd_work *work, u64 id,
> struct file_allocated_range_buffer *qar_req,
> struct file_allocated_range_buffer *qar_rsp,
> - int in_count, int *out_count)
> + unsigned int in_count, unsigned int *out_count)
> {
> struct ksmbd_file *fp;
> loff_t start, length;
> @@ -7208,7 +7216,8 @@ static int fsctl_query_allocated_ranges(struct
> ksmbd_work *work, u64 id,
> }
>
> static int fsctl_pipe_transceive(struct ksmbd_work *work, u64 id,
> - int out_buf_len, struct smb2_ioctl_req *req,
> + unsigned int out_buf_len,
> + struct smb2_ioctl_req *req,
> struct smb2_ioctl_rsp *rsp)
> {
> struct ksmbd_rpc_command *rpc_resp;
> @@ -7322,8 +7331,7 @@ int smb2_ioctl(struct ksmbd_work *work)
> {
> struct smb2_ioctl_req *req;
> struct smb2_ioctl_rsp *rsp, *rsp_org;
> - int cnt_code, nbytes = 0;
> - int out_buf_len;
> + unsigned int cnt_code, nbytes = 0, out_buf_len, in_buf_len;
> u64 id = KSMBD_NO_FID;
> struct ksmbd_conn *conn = work->conn;
> int ret = 0;
> @@ -7352,7 +7360,8 @@ 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(KSMBD_IPC_MAX_PAYLOAD, out_buf_len);
> + out_buf_len = min_t(u32, MAX_STREAM_PROT_LEN, out_buf_len);
I have updated this line to get correct out_buf_len which doesn't
exceed max stream protocl lengh.
+ out_buf_len =
+ min_t(u32, MAX_STREAM_PROT_LEN - offsetof(struct
smb2_ioctl_rsp, Buffer) - 4,
+ out_buf_len);

Will send it on next version.

> + in_buf_len = le32_to_cpu(req->InputCount);
>
> switch (cnt_code) {
> case FSCTL_DFS_GET_REFERRALS:
> @@ -7380,6 +7389,7 @@ int smb2_ioctl(struct ksmbd_work *work)
> break;
> }
> case FSCTL_PIPE_TRANSCEIVE:
> + out_buf_len = min_t(u32, KSMBD_IPC_MAX_PAYLOAD, out_buf_len);
> nbytes = fsctl_pipe_transceive(work, id, out_buf_len, req, rsp);
> break;
> case FSCTL_VALIDATE_NEGOTIATE_INFO:
> @@ -7388,9 +7398,16 @@ int smb2_ioctl(struct ksmbd_work *work)
> goto out;
> }
>
> + if (in_buf_len < sizeof(struct validate_negotiate_info_req))
> + return -EINVAL;
> +
> + if (out_buf_len < sizeof(struct validate_negotiate_info_rsp))
> + return -EINVAL;
> +
> ret = fsctl_validate_negotiate_info(conn,
> (struct validate_negotiate_info_req *)&req->Buffer[0],
> - (struct validate_negotiate_info_rsp *)&rsp->Buffer[0]);
> + (struct validate_negotiate_info_rsp *)&rsp->Buffer[0],
> + in_buf_len);
> if (ret < 0)
> goto out;
>
> @@ -7399,7 +7416,7 @@ int smb2_ioctl(struct ksmbd_work *work)
> rsp->VolatileFileId = cpu_to_le64(SMB2_NO_FID);
> break;
> case FSCTL_QUERY_NETWORK_INTERFACE_INFO:
> - nbytes = fsctl_query_iface_info_ioctl(conn, req, rsp);
> + nbytes = fsctl_query_iface_info_ioctl(conn, rsp, out_buf_len);
> if (nbytes < 0)
> goto out;
> break;
> @@ -7426,15 +7443,33 @@ int smb2_ioctl(struct ksmbd_work *work)
> goto out;
> }
>
> + if (in_buf_len < sizeof(struct copychunk_ioctl_req)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> if (out_buf_len < sizeof(struct copychunk_ioctl_rsp)) {
> ret = -EINVAL;
> goto out;
> }
>
> nbytes = sizeof(struct copychunk_ioctl_rsp);
> - fsctl_copychunk(work, req, rsp);
> + rsp->VolatileFileId = req->VolatileFileId;
> + rsp->PersistentFileId = req->PersistentFileId;
> + fsctl_copychunk(work,
> + (struct copychunk_ioctl_req *)&req->Buffer[0],
> + le32_to_cpu(req->CntCode),
> + le32_to_cpu(req->InputCount),
> + le64_to_cpu(req->VolatileFileId),
> + le64_to_cpu(req->PersistentFileId),
> + rsp);
> break;
> case FSCTL_SET_SPARSE:
> + if (in_buf_len < sizeof(struct file_sparse)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> ret = fsctl_set_sparse(work, id,
> (struct file_sparse *)&req->Buffer[0]);
> if (ret < 0)
> @@ -7453,6 +7488,11 @@ int smb2_ioctl(struct ksmbd_work *work)
> goto out;
> }
>
> + if (in_buf_len < sizeof(struct file_zero_data_information)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> zero_data =
> (struct file_zero_data_information *)&req->Buffer[0];
>
> @@ -7472,6 +7512,11 @@ int smb2_ioctl(struct ksmbd_work *work)
> break;
> }
> case FSCTL_QUERY_ALLOCATED_RANGES:
> + if (in_buf_len < sizeof(struct file_allocated_range_buffer)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> ret = fsctl_query_allocated_ranges(work, id,
> (struct file_allocated_range_buffer *)&req->Buffer[0],
> (struct file_allocated_range_buffer *)&rsp->Buffer[0],
> @@ -7512,6 +7557,11 @@ int smb2_ioctl(struct ksmbd_work *work)
> struct duplicate_extents_to_file *dup_ext;
> loff_t src_off, dst_off, length, cloned;
>
> + if (in_buf_len < sizeof(struct duplicate_extents_to_file)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> dup_ext = (struct duplicate_extents_to_file *)&req->Buffer[0];
>
> fp_in = ksmbd_lookup_fd_slow(work, dup_ext->VolatileFileHandle,
> diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c
> index b41954294d38..835b384b0895 100644
> --- a/fs/ksmbd/vfs.c
> +++ b/fs/ksmbd/vfs.c
> @@ -1023,7 +1023,7 @@ int ksmbd_vfs_zero_data(struct ksmbd_work *work,
> struct ksmbd_file *fp,
>
> int ksmbd_vfs_fqar_lseek(struct ksmbd_file *fp, loff_t start, loff_t
> length,
> struct file_allocated_range_buffer *ranges,
> - int in_count, int *out_count)
> + unsigned int in_count, unsigned int *out_count)
> {
> struct file *f = fp->filp;
> struct inode *inode = file_inode(fp->filp);
> diff --git a/fs/ksmbd/vfs.h b/fs/ksmbd/vfs.h
> index 7b1dcaa3fbdc..b0d5b8feb4a3 100644
> --- a/fs/ksmbd/vfs.h
> +++ b/fs/ksmbd/vfs.h
> @@ -166,7 +166,7 @@ int ksmbd_vfs_zero_data(struct ksmbd_work *work, struct
> ksmbd_file *fp,
> struct file_allocated_range_buffer;
> int ksmbd_vfs_fqar_lseek(struct ksmbd_file *fp, loff_t start, loff_t
> length,
> struct file_allocated_range_buffer *ranges,
> - int in_count, int *out_count);
> + unsigned int in_count, unsigned int *out_count);
> int ksmbd_vfs_unlink(struct user_namespace *user_ns,
> struct dentry *dir, struct dentry *dentry);
> void *ksmbd_vfs_init_kstat(char **p, struct ksmbd_kstat *ksmbd_kstat);
> --
> 2.25.1
>
>