6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon [ Upstream commit f25e93768fcc5d8287e50b1ec52a42e4c276df34 ] Validate IPC share configuration payload sizes before consuming variable-length fields. Bound veto list parsing and account for the separator byte when deriving the path length. Fixes: a677ebd8ca2f ("ksmbd: validate payload size in ipc response") Reported-by: Kanishka De Silva Reported-by: Farhad Alemi Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin --- fs/smb/server/mgmt/share_config.c | 38 +++++++++++++++++++++++-------- fs/smb/server/transport_ipc.c | 21 +++++++++++------ 2 files changed, 42 insertions(+), 17 deletions(-) diff --git a/fs/smb/server/mgmt/share_config.c b/fs/smb/server/mgmt/share_config.c index d8d03070ae44b..7db7345f1af94 100644 --- a/fs/smb/server/mgmt/share_config.c +++ b/fs/smb/server/mgmt/share_config.c @@ -88,9 +88,9 @@ static struct ksmbd_share_config *__share_lookup(const char *name) static int parse_veto_list(struct ksmbd_share_config *share, char *veto_list, - int veto_list_sz) + size_t veto_list_sz) { - int sz = 0; + size_t sz; if (!veto_list_sz) return 0; @@ -98,7 +98,7 @@ static int parse_veto_list(struct ksmbd_share_config *share, while (veto_list_sz > 0) { struct ksmbd_veto_pattern *p; - sz = strlen(veto_list); + sz = strnlen(veto_list, veto_list_sz); if (!sz) break; @@ -106,7 +106,7 @@ static int parse_veto_list(struct ksmbd_share_config *share, if (!p) return -ENOMEM; - p->pattern = kstrdup(veto_list, GFP_KERNEL); + p->pattern = kstrndup(veto_list, sz, GFP_KERNEL); if (!p->pattern) { kfree(p); return -ENOMEM; @@ -114,6 +114,9 @@ static int parse_veto_list(struct ksmbd_share_config *share, list_add(&p->list, &share->veto_list); + if (sz == veto_list_sz) + break; + veto_list += sz + 1; veto_list_sz -= (sz + 1); } @@ -160,13 +163,27 @@ static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work, share->name = kstrdup(name, GFP_KERNEL); if (!test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) { - int path_len = PATH_MAX; + size_t path_len; - if (resp->payload_sz) + if (resp->payload_sz <= resp->veto_list_sz) { + ret = -EINVAL; + } else { path_len = resp->payload_sz - resp->veto_list_sz; - - share->path = kstrndup(ksmbd_share_config_path(resp), path_len, - GFP_KERNEL); + if (resp->veto_list_sz) + path_len--; + + if (!path_len) { + ret = -EINVAL; + } else { + share->path = kstrndup( + ksmbd_share_config_path(resp), + path_len, GFP_KERNEL); + if (!share->path) + ret = -ENOMEM; + else + ret = 0; + } + } if (share->path) { share->path_sz = strlen(share->path); while (share->path_sz > 1 && @@ -179,7 +196,8 @@ static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work, share->force_directory_mode = resp->force_directory_mode; share->force_uid = resp->force_uid; share->force_gid = resp->force_gid; - ret = parse_veto_list(share, + if (!ret) + ret = parse_veto_list(share, KSMBD_SHARE_CONFIG_VETO_LIST(resp), resp->veto_list_sz); if (!ret && share->path) { diff --git a/fs/smb/server/transport_ipc.c b/fs/smb/server/transport_ipc.c index bbe039a05b1c3..80fd1316d176b 100644 --- a/fs/smb/server/transport_ipc.c +++ b/fs/smb/server/transport_ipc.c @@ -524,14 +524,21 @@ static int ipc_validate_msg(struct ipc_msg_table_entry *entry) if (entry->msg_sz < sizeof(struct ksmbd_share_config_response)) return -EINVAL; - if (resp->payload_sz) { - if (resp->payload_sz < resp->veto_list_sz) - return -EINVAL; + if (strnlen(resp->share_name, sizeof(resp->share_name)) == + sizeof(resp->share_name)) + return -EINVAL; - if (check_add_overflow(sizeof(struct ksmbd_share_config_response), - resp->payload_sz, &msg_sz)) - return -EINVAL; - } + if (resp->veto_list_sz > resp->payload_sz) + return -EINVAL; + + if (resp->flags != KSMBD_SHARE_FLAG_INVALID && + !(resp->flags & KSMBD_SHARE_FLAG_PIPE) && + resp->payload_sz <= resp->veto_list_sz) + return -EINVAL; + + if (check_add_overflow(sizeof(struct ksmbd_share_config_response), + resp->payload_sz, &msg_sz)) + return -EINVAL; break; } case KSMBD_EVENT_LOGIN_REQUEST_EXT: -- 2.53.0